CS-Notes/notes/计算机网络.md

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* [<EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD>](#<23><>һ<EFBFBD><D2BB>-<2D><><EFBFBD><EFBFBD>)
    * [<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#<23><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
    * [ISP](#isp)
    * [<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#<23><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
    * [<EFBFBD><EFBFBD><EFBFBD><EFBFBD>֮<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD>ŷ<EFBFBD>ʽ](#<23><><EFBFBD><EFBFBD>֮<EFBFBD><D6AE><EFBFBD><EFBFBD>ͨ<EFBFBD>ŷ<EFBFBD>ʽ)
    * [<EFBFBD><EFBFBD>·<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>齻<EFBFBD><EFBFBD>](#<23><>·<EFBFBD><C2B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>齻<EFBFBD><E9BDBB>)
        * [1. <20><>·<EFBFBD><C2B7><EFBFBD><EFBFBD>](#1-<2D><>·<EFBFBD><C2B7><EFBFBD><EFBFBD>)
        * [2. <20><><EFBFBD>Ľ<EFBFBD><C4BD><EFBFBD>](#2-<2D><><EFBFBD>Ľ<EFBFBD><C4BD><EFBFBD>)
        * [3. <20><><EFBFBD>齻<EFBFBD><E9BDBB>](#3-<2D><><EFBFBD>齻<EFBFBD><E9BDBB>)
    * [ʱ<EFBFBD><EFBFBD>](#ʱ<><CAB1>)
        * [1. <20><><EFBFBD><EFBFBD>ʱ<EFBFBD><CAB1>](#1-<2D><><EFBFBD><EFBFBD>ʱ<EFBFBD><CAB1>)
        * [2. <20><><EFBFBD><EFBFBD>ʱ<EFBFBD><CAB1>](#2-<2D><><EFBFBD><EFBFBD>ʱ<EFBFBD><CAB1>)
        * [3. <20><><EFBFBD><EFBFBD>ʱ<EFBFBD><CAB1>](#3-<2D><><EFBFBD><EFBFBD>ʱ<EFBFBD><CAB1>)
        * [4. <20>Ŷ<EFBFBD>ʱ<EFBFBD><CAB1>](#4-<2D>Ŷ<EFBFBD>ʱ<EFBFBD><CAB1>)
    * [<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϵ<EFBFBD>ṹ*](#<23><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϵ<EFBFBD>ṹ)
        * [1. <20>߲<EFBFBD>Э<EFBFBD><D0AD>](#1-<2D>߲<EFBFBD>Э<EFBFBD><D0AD>)
        * [2. <20><><EFBFBD><EFBFBD>Э<EFBFBD><D0AD>](#2-<2D><><EFBFBD><EFBFBD>Э<EFBFBD><D0AD>)
        * [3. <20><><EFBFBD><EFBFBD><EFBFBD>ڸ<EFBFBD><DAB8><EFBFBD>֮<EFBFBD><D6AE><EFBFBD>Ĵ<EFBFBD><C4B4>ݹ<EFBFBD><DDB9><EFBFBD>](#3-<2D><><EFBFBD><EFBFBD><EFBFBD>ڸ<EFBFBD><DAB8><EFBFBD>֮<EFBFBD><D6AE><EFBFBD>Ĵ<EFBFBD><C4B4>ݹ<EFBFBD><DDB9><EFBFBD>)
        * [4. TCP/IP <20><>ϵ<EFBFBD>ṹ](#4-tcpip-<2D><>ϵ<EFBFBD>ṹ)
* [<EFBFBD>ڶ<EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#<23>ڶ<EFBFBD><DAB6><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
    * [ͨ<EFBFBD>ŷ<EFBFBD>ʽ](#ͨ<>ŷ<EFBFBD>ʽ)
    * [<EFBFBD><EFBFBD>ͨ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#<23><>ͨ<EFBFBD><CDA8><EFBFBD><EFBFBD>)
    * [<EFBFBD>ŵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ü<EFBFBD><EFBFBD><EFBFBD>](#<23>ŵ<EFBFBD><C5B5><EFBFBD><EFBFBD>ü<EFBFBD><C3BC><EFBFBD>)
        * [1. Ƶ<>ָ<EFBFBD><D6B8>á<EFBFBD>ʱ<EFBFBD>ָ<EFBFBD><D6B8><EFBFBD>](#1-Ƶ<>ָ<EFBFBD><D6B8><EFBFBD>ʱ<EFBFBD>ָ<EFBFBD><D6B8><EFBFBD>)
        * [2. ͳ<><CDB3>ʱ<EFBFBD>ָ<EFBFBD><D6B8><EFBFBD>](#2-ͳ<><CDB3>ʱ<EFBFBD>ָ<EFBFBD><D6B8><EFBFBD>)
        * [3. <20><><EFBFBD>ָ<EFBFBD><D6B8><EFBFBD>](#3-<2D><><EFBFBD>ָ<EFBFBD><D6B8><EFBFBD>)
        * [4. <20><><EFBFBD>ָ<EFBFBD><D6B8><EFBFBD>](#4-<2D><><EFBFBD>ָ<EFBFBD><D6B8><EFBFBD>)
* [<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><C2B7>](#<23><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><C2B7>)
    * [<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#<23><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
        * [1. <20><>װ<EFBFBD><D7B0>֡](#1-<2D><>װ<EFBFBD><D7B0>֡)
        * [2. ͸<><CDB8><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#2-͸<><CDB8><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
        * [3. <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#3-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
    * [<EFBFBD><EFBFBD><EFBFBD>Ե<EFBFBD><EFBFBD>ŵ<EFBFBD> - PPP Э<><D0AD>](#<23><><EFBFBD>Ե<EFBFBD><D4B5>ŵ<EFBFBD>---ppp-Э<><D0AD>)
    * [<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#<23><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
    * [<EFBFBD>㲥<EFBFBD>ŵ<EFBFBD> - CSMA/CD Э<><D0AD>*](#<23>㲥<EFBFBD>ŵ<EFBFBD>---csmacd-Э<><D0AD>)
    * [<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#<23><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
    * [MAC <20><>](#mac-<2D><>)
    * [<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#<23><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
* [<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>*](#<23><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
    * [<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Э<EFBFBD><EFBFBD> IP <20><><EFBFBD><EFBFBD>](#<23><><EFBFBD><EFBFBD>Э<EFBFBD><D0AD>-ip-<2D><><EFBFBD><EFBFBD>)
    * [IP <20><><EFBFBD>ݱ<EFBFBD><DDB1><EFBFBD>ʽ](#ip-<2D><><EFBFBD>ݱ<EFBFBD><DDB1><EFBFBD>ʽ)
    * [IP <20><>ַ<EFBFBD><D6B7>ַ](#ip-<2D><>ַ<EFBFBD><D6B7>ַ)
        * [1. <20><><EFBFBD><EFBFBD>](#1-<2D><><EFBFBD><EFBFBD>)
        * [2. <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#2-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
        * [3. <20>޷<EFBFBD><DEB7><EFBFBD>](#3-<2D>޷<EFBFBD><DEB7><EFBFBD>)
    * [IP <20><>ַ<EFBFBD><D6B7> MAC <20><>ַ](#ip-<2D><>ַ<EFBFBD><D6B7>-mac-<2D><>ַ)
    * [<EFBFBD><EFBFBD>ַ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Э<EFBFBD><EFBFBD> ARP](#<23><>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD>Э<EFBFBD><D0AD>-arp)
    * [·<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ľṹ](#·<><C2B7><EFBFBD><EFBFBD><EFBFBD>Ľṹ)
    * [<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#<23><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><C2B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
    * [·<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ת<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#·<><C2B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ת<EFBFBD><D7AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
    * [·<EFBFBD><EFBFBD>ѡ<EFBFBD><EFBFBD>Э<EFBFBD><EFBFBD>](#·<><C2B7>ѡ<EFBFBD><D1A1>Э<EFBFBD><D0AD>)
        * [1. <20>ڲ<EFBFBD><DAB2><EFBFBD><EFBFBD><EFBFBD>Э<EFBFBD><D0AD> RIP](#1-<2D>ڲ<EFBFBD><DAB2><EFBFBD><EFBFBD><EFBFBD>Э<EFBFBD><D0AD>-rip)
        * [2. <20>ڲ<EFBFBD><DAB2><EFBFBD><EFBFBD><EFBFBD>Э<EFBFBD><D0AD> OSPF](#2-<2D>ڲ<EFBFBD><DAB2><EFBFBD><EFBFBD><EFBFBD>Э<EFBFBD><D0AD>-ospf)
        * [3. <20>ⲿ<EFBFBD><E2B2BF><EFBFBD><EFBFBD>Э<EFBFBD><D0AD> BGP](#3-<2D>ⲿ<EFBFBD><E2B2BF><EFBFBD><EFBFBD>Э<EFBFBD><D0AD>-bgp)
    * [<EFBFBD><EFBFBD><EFBFBD>ʿ<EFBFBD><EFBFBD>Ʊ<EFBFBD><EFBFBD><EFBFBD>Э<EFBFBD><EFBFBD> ICMP](#<23><><EFBFBD>ʿ<EFBFBD><CABF>Ʊ<EFBFBD><C6B1><EFBFBD>Э<EFBFBD><D0AD>-icmp)
    * [<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̽<EFBFBD><EFBFBD> PING](#<23><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̽<EFBFBD><CCBD>-ping)
    * [IP <20>ಥ](#ip-<2D>ಥ)
    * [<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ר<EFBFBD><EFBFBD><EFBFBD><EFBFBD> VPN](#<23><><EFBFBD><EFBFBD>ר<EFBFBD><D7A8><EFBFBD><EFBFBD>-vpn)
    * [<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ַת<EFBFBD><EFBFBD> NAT](#<23><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ַת<D6B7><D7AA>-nat)
* [<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>*](#<23><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
    * [UDP <20><> TCP <20><><EFBFBD>ص<EFBFBD>](#udp-<2D><>-tcp-<2D><><EFBFBD>ص<EFBFBD>)
    * [UDP <20>ײ<EFBFBD><D7B2><EFBFBD>ʽ](#udp-<2D>ײ<EFBFBD><D7B2><EFBFBD>ʽ)
    * [TCP <20>ײ<EFBFBD><D7B2><EFBFBD>ʽ](#tcp-<2D>ײ<EFBFBD><D7B2><EFBFBD>ʽ)
    * [TCP <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#tcp-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
    * [TCP <20><><EFBFBD>Ĵλ<C4B4><CEBB><EFBFBD>](#tcp-<2D><><EFBFBD>Ĵλ<C4B4><CEBB><EFBFBD>)
    * [TCP <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#tcp-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
    * [TCP <20>ɿ<EFBFBD><C9BF><EFBFBD><EFBFBD><EFBFBD>](#tcp-<2D>ɿ<EFBFBD><C9BF><EFBFBD><EFBFBD><EFBFBD>)
    * [TCP <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#tcp-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
    * [TCP ӵ<><D3B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#tcp-ӵ<><D3B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
        * [<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʼ<EFBFBD><EFBFBD>ӵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#<23><><EFBFBD><EFBFBD>ʼ<EFBFBD><CABC>ӵ<EFBFBD><D3B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
        * [<EFBFBD><EFBFBD><EFBFBD>ش<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ָ<EFBFBD>](#<23><><EFBFBD>ش<EFBFBD><D8B4><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ָ<EFBFBD>)
* [<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Ӧ<>ò<EFBFBD>*](#<23><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-Ӧ<>ò<EFBFBD>)
    * [<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϵͳ DNS](#<23><><EFBFBD><EFBFBD>ϵͳ-dns)
        * [1. <20><><EFBFBD>νṹ](#1-<2D><><EFBFBD>νṹ)
        * [2. <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#2-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
    * [<EFBFBD>ļ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Э<EFBFBD><EFBFBD> FTP](#<23>ļ<EFBFBD><C4BC><EFBFBD><EFBFBD><EFBFBD>Э<EFBFBD><D0AD>-ftp)
    * [Զ<EFBFBD><EFBFBD><EFBFBD>ն<EFBFBD>Э<EFBFBD><EFBFBD> TELNET](#Զ<><D4B6><EFBFBD>ն<EFBFBD>Э<EFBFBD><D0AD>-telnet)
    * [<EFBFBD><EFBFBD>ά<EFBFBD><EFBFBD> WWW](#<23><>ά<EFBFBD><CEAC>-www)
    * [<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʼ<EFBFBD>Э<EFBFBD><EFBFBD>](#<23><><EFBFBD><EFBFBD><EFBFBD>ʼ<EFBFBD>Э<EFBFBD><D0AD>)
        * [POP3](#pop3)
        * [IMAP](#imap)
        * [SMTP](#smtp)
    * [<EFBFBD><EFBFBD>̬<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Э<EFBFBD><EFBFBD> DHCP](#<23><>̬<EFBFBD><CCAC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Э<EFBFBD><D0AD>-dhcp)
    * [<EFBFBD><EFBFBD><EFBFBD>Ե㴫<EFBFBD><EFBFBD> P2P](#<23><><EFBFBD>Ե㴫<D4B5><E3B4AB>-p2p)
    * [Web ҳ<><D2B3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#web-ҳ<><D2B3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
    * [<EFBFBD><EFBFBD><EFBFBD>ö˿<EFBFBD>](#<23><><EFBFBD>ö˿<C3B6>)
* [<EFBFBD>ο<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#<23>ο<EFBFBD><CEBF><EFBFBD><EFBFBD><EFBFBD>)
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# <20><>һ<EFBFBD><D2BB> <20><><EFBFBD><EFBFBD>

## <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǰѶ<EFBFBD><EFBFBD>ֲ<EFBFBD>ͬ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>˻<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>硣

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/04ff7ae6-7bee-4cf8-82f8-dfe2ba1f3616.jpg)

## ISP

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ṩ<EFBFBD><EFBFBD> ISP <20><><EFBFBD>Դӻ<D4B4><D3BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> IP <20><>ַ<EFBFBD><D6B7>ͬʱӵ<CAB1><D3B5>ͨ<EFBFBD><CDA8><EFBFBD><EFBFBD>·<EFBFBD>Լ<EFBFBD>·<EFBFBD><C2B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>豸<EFBFBD><E8B1B8><EFBFBD><EFBFBD><EFBFBD>˻<EFBFBD><CBBB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> ISP <20><><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD>ķ<EFBFBD><C4B7>þͿ<C3BE><CDBF>Խ<EFBFBD><D4BD>뻥<EFBFBD><EBBBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

Ŀǰ<EFBFBD>Ļ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD>ֶ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> ISP <20>ṹ<EFBFBD><E1B9B9>ISP <20><><EFBFBD>ݸ<EFBFBD><DDB8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ĵ<EFBFBD>С<EFBFBD><D0A1>Ϊ<EFBFBD><CEAA><EFBFBD><EFBFBD> ISP<53><50><EFBFBD><EFBFBD><EFBFBD><EFBFBD> ISP <20>ͱ<EFBFBD><CDB1><EFBFBD> ISP<53><50>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> IXP <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> ISP ֱ<><D6B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>þ<EFBFBD><C3BE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> ISP<53><50>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/17d807ef-03bf-4824-a97c-ea5fb58ec61d.jpg)

## <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

1. <20><>Ե<EFBFBD><D4B5><EFBFBD>֣<EFBFBD><D6A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڻ<EFBFBD><DABB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϵ<EFBFBD><CFB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>û<EFBFBD><C3BB><EFBFBD><EFBFBD><EFBFBD>ֱ<EFBFBD><D6B1>ʹ<EFBFBD>ã<EFBFBD>
2. <20><><EFBFBD>IJ<EFBFBD><C4B2>֣<EFBFBD><D6A3>ɴ<EFBFBD><C9B4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Щ<EFBFBD><D0A9><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><C2B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ɣ<EFBFBD>Ϊ<EFBFBD><CEAA>Ե<EFBFBD><D4B5><EFBFBD>ֵ<EFBFBD><D6B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ṩ<EFBFBD><E1B9A9><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/005d83c2-e64a-41f0-bbdd-51c71d494a18.jpg)

## <20><><EFBFBD><EFBFBD>֮<EFBFBD><D6AE><EFBFBD><EFBFBD>ͨ<EFBFBD>ŷ<EFBFBD>ʽ

**1. <20>ͻ<EFBFBD> - <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>C/S<><53>**

<EFBFBD>ͻ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ƿ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>󷽣<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ƿ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ṩ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>

**2. <20>Եȣ<D4B5>P2P<32><50>**

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֿͻ<EFBFBD><EFBFBD>ͷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

## <20><>·<EFBFBD><C2B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>齻<EFBFBD><E9BDBB>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/b97958dd-3e43-45f7-97f5-3ec20f3f8b88.jpg)

### 1. <20><>·<EFBFBD><C2B7><EFBFBD><EFBFBD>

<EFBFBD><EFBFBD>·<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڵ绰ͨ<EFBFBD><EFBFBD>ϵͳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>û<EFBFBD>Ҫͨ<EFBFBD><EFBFBD>֮ǰ<EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD>ר<EFBFBD>õ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD>Ź<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʼ<EFBFBD><EFBFBD>ռ<EFBFBD>ø<EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD>ŵĹ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>в<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һֱ<EFBFBD><EFBFBD>ʹ<EFBFBD>ô<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>˵<EFBFBD>·<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʺܵͣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 10%<25><>

### 2. <20><><EFBFBD>Ľ<EFBFBD><C4BD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD>Ľ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʾ<EFBFBD>ͨ<EFBFBD><EFBFBD>ϵͳ<EFBFBD><EFBFBD><EFBFBD>ʾֽ<EFBFBD><EFBFBD>յ<EFBFBD>һ<EFBFBD>ݱ<EFBFBD><EFBFBD><EFBFBD>֮<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȴ洢<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ȼ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͬĿ<EFBFBD>ĵصı<EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD>ת<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD>Ŀ<EFBFBD>ĵأ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̾<EFBFBD><EFBFBD>Ǵ洢ת<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̡<EFBFBD>

### 3. <20><><EFBFBD>齻<EFBFBD><E9BDBB>

<EFBFBD><EFBFBD><EFBFBD>齻<EFBFBD><EFBFBD>Ҳʹ<EFBFBD><EFBFBD><EFBFBD>˴洢ת<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ת<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ƿ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>DZ<EFBFBD><EFBFBD>ġ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݳ<EFBFBD>Ϊһ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ģ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ŀ<EFBFBD><EFBFBD>ܺܳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD>Ƚ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>з֣<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ܴ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ĵ<EFBFBD>С<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ÿ<EFBFBD><EFBFBD><EFBFBD>зֵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǰ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ײ<EFBFBD>֮<EFBFBD><EFBFBD><EFBFBD>ͳ<EFBFBD>Ϊ<EFBFBD>˷<EFBFBD><EFBFBD>飬<EFBFBD>ײ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ŀ<EFBFBD>ĵ<EFBFBD>ַ<EFBFBD><EFBFBD>Դ<EFBFBD><EFBFBD>ַ<EFBFBD>ȿ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϣ<EFBFBD><EFBFBD>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/6f4af159-8b03-4246-8d0e-222db65bb83c.jpg)

<EFBFBD>洢ת<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD>ϴ<EFBFBD><EFBFBD>Ͷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ķ<EFBFBD><EFBFBD>飬<EFBFBD><EFBFBD><EFBFBD>˲<EFBFBD><EFBFBD><EFBFBD>Ҫռ<EFBFBD>ö˵<EFBFBD><EFBFBD>˵<EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><EFBFBD>Դ<EFBFBD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڱ<EFBFBD><EFBFBD>Ľ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȱ<EFBFBD><EFBFBD>ĸ<EFBFBD>С<EFBFBD><EFBFBD><EFBFBD>洢ת<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ٶ<EFBFBD>Ҳ<EFBFBD>͸<EFBFBD><EFBFBD>졣

## ʱ<><CAB1>

<EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD> = <20><><EFBFBD><EFBFBD>ʱ<EFBFBD><CAB1> + <20><><EFBFBD><EFBFBD>ʱ<EFBFBD><CAB1> + <20><><EFBFBD><EFBFBD>ʱ<EFBFBD><CAB1> + <20>Ŷ<EFBFBD>ʱ<EFBFBD><CAB1>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/ceee91c2-da26-4169-94c3-e4608b46b9ac.png)

### 1. <20><><EFBFBD><EFBFBD>ʱ<EFBFBD><CAB1>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>֡<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD>ʱ<EFBFBD>䡣

![](http://latex.codecogs.com/gif.latex?\\\\delay=\frac{l(bit)}{v(bit/s)})

<EFBFBD><EFBFBD><EFBFBD><EFBFBD> l <20><>ʾ<EFBFBD><CABE><EFBFBD><EFBFBD>֡<EFBFBD>ij<EFBFBD><C4B3>ȣ<EFBFBD>v <20><>ʾ<EFBFBD><CABE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʡ<EFBFBD>

### 2. <20><><EFBFBD><EFBFBD>ʱ<EFBFBD><CAB1>

<EFBFBD><EFBFBD><EFBFBD>Ų<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ŵ<EFBFBD><EFBFBD>д<EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD>ľ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD><EFBFBD>ѵ<EFBFBD>ʱ<EFBFBD>䣬<EFBFBD><EFBFBD><EFBFBD>Ų<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ٶȽӽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>١<EFBFBD>

![](http://latex.codecogs.com/gif.latex?\\\\delay=\frac{l(m)}{v(m/s)})

<EFBFBD><EFBFBD><EFBFBD><EFBFBD> l <20><>ʾ<EFBFBD>ŵ<EFBFBD><C5B5><EFBFBD><EFBFBD>ȣ<EFBFBD>v <20><>ʾ<EFBFBD><CABE><EFBFBD>Ų<EFBFBD><C5B2><EFBFBD><EFBFBD>ŵ<EFBFBD><C5B5>ϵĴ<CFB5><C4B4><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʡ<EFBFBD>

### 3. <20><><EFBFBD><EFBFBD>ʱ<EFBFBD><CAB1>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>յ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD>д<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD>ʱ<EFBFBD>䣬<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ײ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȡ<EFBFBD><EFBFBD><EFBFBD>ݲ<EFBFBD><EFBFBD>ֵȡ<EFBFBD>

### 4. <20>Ŷ<EFBFBD>ʱ<EFBFBD><CAB1>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>к<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ŷӵȴ<EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD>䣬ȡ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>統ǰ<EFBFBD><EFBFBD>ͨ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

## <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϵ<EFBFBD>ṹ*

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/1005dc9d-9049-4b06-9524-6171e56ebd8c.png)

### 1. <20>߲<EFBFBD>Э<EFBFBD><D0AD>

<EFBFBD><EFBFBD>ͼ a <20><>ʾ<EFBFBD><CABE><EFBFBD><EFBFBD><EFBFBD>б<EFBFBD>ʾ<EFBFBD><CABE><EFBFBD>ͻỰ<CDBB><E1BBB0><EFBFBD><EFBFBD>;<EFBFBD><CDBE><EFBFBD>£<EFBFBD>

1. <20><>ʾ<EFBFBD>㣺<EFBFBD><E3A3BA>Ϣ<EFBFBD><CFA2><EFBFBD>﷨<EFBFBD><EFB7A8><EFBFBD><EFBFBD><EFBFBD>Լ<EFBFBD><D4BC><EFBFBD><EFBFBD>ǵĹ<C7B5><C4B9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ܽ<EFBFBD><DCBD>ܡ<EFBFBD>ת<EFBFBD><D7AA><EFBFBD><EFBFBD><EFBFBD>롢ѹ<EBA1A2><D1B9><EFBFBD><EFBFBD>ѹ<EFBFBD><D1B9><EFBFBD><EFBFBD>
2. <20>Ự<EFBFBD>㣺<EFBFBD><E3A3BA>ͬ<EFBFBD><CDAC><EFBFBD><EFBFBD><EFBFBD>ϵ<EFBFBD><CFB5>û<EFBFBD>֮<EFBFBD>佨<EFBFBD><E4BDA8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ự<EFBFBD><E1BBB0>

### 2. <20><><EFBFBD><EFBFBD>Э<EFBFBD><D0AD>

1. Ӧ<>ò㣺Ϊ<E3A3BA>ض<EFBFBD>Ӧ<EFBFBD>ó<EFBFBD><C3B3><EFBFBD><EFBFBD>ṩ<EFBFBD><E1B9A9><EFBFBD>ݴ<EFBFBD><DDB4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> HTTP<54><50>DNS <20>ȡ<EFBFBD><C8A1><EFBFBD><EFBFBD>ݵ<EFBFBD>λΪ<CEBB><CEAA><EFBFBD>ġ<EFBFBD>

2. <20><><EFBFBD><EFBFBD><EFBFBD>㣺<EFBFBD>ṩ<EFBFBD><E1B9A9><EFBFBD>ǽ<EFBFBD><C7BD>̼<EFBFBD><CCBC><EFBFBD>ͨ<EFBFBD><CDA8><EFBFBD><EFBFBD><EFBFBD>ݴ<EFBFBD><DDB4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ӧ<EFBFBD>ò<EFBFBD>Э<EFBFBD><D0AD><EFBFBD>ܶ࣬<DCB6><E0A3AC><EFBFBD><EFBFBD>ͨ<EFBFBD>õ<EFBFBD><C3B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Э<EFBFBD><D0AD><EFBFBD>Ϳ<EFBFBD><CDBF><EFBFBD>֧<EFBFBD>ֲ<EFBFBD><D6B2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ӧ<EFBFBD>ò<EFBFBD>Э<EFBFBD>顣<EFBFBD><E9A1A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Э<EFBFBD>飺<EFBFBD><E9A3BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Э<EFBFBD><D0AD> TCP<43><50><EFBFBD>ṩ<EFBFBD><E1B9A9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӡ<EFBFBD><D3A1>ɿ<EFBFBD><C9BF><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݴ<EFBFBD><DDB4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݵ<EFBFBD>λΪ<CEBB><CEAA><EFBFBD>ĶΣ<C4B6><CEA3>û<EFBFBD><C3BB><EFBFBD><EFBFBD>ݱ<EFBFBD>Э<EFBFBD><D0AD> UDP<44><50><EFBFBD>ṩ<EFBFBD><E1B9A9><EFBFBD><EFBFBD><EFBFBD>ӡ<EFBFBD><D3A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ŭ<EFBFBD><C5AC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݴ<EFBFBD><DDB4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݵ<EFBFBD>λΪ<CEBB>û<EFBFBD><C3BB><EFBFBD><EFBFBD>ݱ<EFBFBD><DDB1><EFBFBD>

3. <20><><EFBFBD><EFBFBD><EFBFBD>㣺Ϊ<E3A3BA><CEAA><EFBFBD><EFBFBD>֮<EFBFBD><D6AE><EFBFBD>ṩ<EFBFBD><E1B9A9><EFBFBD>񣬶<EFBFBD><F1A3ACB6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Э<EFBFBD><D0AD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD><CEAA><EFBFBD><EFBFBD><EFBFBD>еĽ<D0B5><C4BD><EFBFBD><EFBFBD>ṩ<EFBFBD><E1B9A9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ı<EFBFBD><C4B1>Ķλ<C4B6><CEBB><EFBFBD><EFBFBD>û<EFBFBD><C3BB><EFBFBD><EFBFBD>ݱ<EFBFBD><DDB1><EFBFBD>װ<EFBFBD>ɷ<EFBFBD><C9B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>д<EFBFBD><D0B4>䡣

4. <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD>㣺<EFBFBD><E3A3BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ԵĻ<D4B5><C4BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>֮<EFBFBD>䣬<EFBFBD><E4A3AC><EFBFBD><EFBFBD><EFBFBD><EFBFBD>֮<EFBFBD><D6AE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>кܶ<D0BA><DCB6><EFBFBD>·<EFBFBD><C2B7><EFBFBD><EFBFBD>·<EFBFBD><C2B7>Э<EFBFBD><D0AD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD><CEAA><EFBFBD>ڽ<EFBFBD><DABD><EFBFBD>֮<EFBFBD><D6AE><EFBFBD>ṩ<EFBFBD><E1B9A9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><C2B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>㴫<EFBFBD><E3B4AB><EFBFBD>ķ<EFBFBD><C4B7><EFBFBD><EFBFBD><EFBFBD>װ<EFBFBD><D7B0>֡<EFBFBD><D6A1>

5. <20><><EFBFBD><EFBFBD><EFBFBD>㣺<EFBFBD><E3A3BA><EFBFBD>ǵ<EFBFBD><C7B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڴ<EFBFBD><DAB4><EFBFBD>ý<EFBFBD><C3BD><EFBFBD>ϴ<EFBFBD><CFB4><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݱ<EFBFBD><DDB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ָ<EFBFBD><D6B8><EFBFBD><EFBFBD><EFBFBD>Ĵ<EFBFBD><C4B4><EFBFBD>ý<EFBFBD>塣<EFBFBD><E5A1A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ǿ<EFBFBD><C7BE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>δ<EFBFBD><CEB4><EFBFBD>ý<EFBFBD><C3BD><EFBFBD><EFBFBD>ͨ<EFBFBD><CDA8><EFBFBD>ֶεIJ<CEB5><C4B2>죬ʹ<ECA3AC><CAB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϵ<EFBFBD><CFB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><C2B7><EFBFBD>о<EFBFBD><D0BE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Щ<EFBFBD><D0A9><EFBFBD>졣

### 3. <20><><EFBFBD><EFBFBD><EFBFBD>ڸ<EFBFBD><DAB8><EFBFBD>֮<EFBFBD><D6AE><EFBFBD>Ĵ<EFBFBD><C4B4>ݹ<EFBFBD><DDB9><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>µĹ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>У<EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>²<EFBFBD>Э<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD><EFBFBD>ײ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>β<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϵĹ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>в<EFBFBD><EFBFBD>ϲ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ײ<EFBFBD><EFBFBD><EFBFBD>β<EFBFBD><EFBFBD><EFBFBD><EFBFBD>

·<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֻ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Э<EFBFBD>飬<EFBFBD><EFBFBD>Ϊ·<EFBFBD><EFBFBD><EFBFBD><EFBFBD>λ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>У<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ҪΪ<EFBFBD><EFBFBD><EFBFBD>̻<EFBFBD><EFBFBD><EFBFBD>Ӧ<EFBFBD>ó<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ṩ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҳ<EFBFBD>Ͳ<EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ӧ<EFBFBD>ò㡣

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/f7d5da89-2d75-4d8f-85e7-6b608865dc00.jpg)

### 4. TCP/IP <20><>ϵ<EFBFBD>ṹ

<EFBFBD><EFBFBD>ֻ<EFBFBD><EFBFBD><EFBFBD>IJ㣬<EFBFBD>൱<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Э<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϲ<EFBFBD>Ϊ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӿڲ㡣

<EFBFBD><EFBFBD><EFBFBD>ڵ<EFBFBD> TCP/IP <20><>ϵ<EFBFBD>ṹ<EFBFBD><E1B9B9><EFBFBD>ϸ<EFBFBD><CFB8><EFBFBD>ѭ OSI <20>ֲ<EFBFBD><D6B2><EFBFBD><EFBFBD>Ӧ<EEA3AC>ò<EFBFBD><C3B2><EFBFBD><EFBFBD>ܻ<EFBFBD>ֱ<EFBFBD><D6B1>ʹ<EFBFBD><CAB9> IP <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӿڲ㡣

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/3e2200b3-1c18-4853-ae42-7788e8e1f939.png)

TCP/IP Э<><D0AD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB>ɳ©<C9B3><C2A9>״<EFBFBD><D7B4><EFBFBD>м<EFBFBD>С<EFBFBD><D0A1><EFBFBD>ߴ<EFBFBD><DFB4><EFBFBD>IP Э<><D0AD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ռ<EFBFBD>þ<EFBFBD><C3BE><EFBFBD><EFBFBD><EFBFBD><EFBFBD>صĵ<D8B5>λ<EFBFBD><CEBB>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/9ecaebee-670e-4cb2-9cdb-3029c00f33bd.png)

# <20>ڶ<EFBFBD><DAB6><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

## ͨ<>ŷ<EFBFBD>ʽ

1. <20><><EFBFBD><EFBFBD>ͨ<EFBFBD>ţ<EFBFBD><C5A3>ֳ<EFBFBD>Ϊ<EFBFBD><CEAA><EFBFBD><EFBFBD>ͨ<EFBFBD>ţ<EFBFBD>
2. ˫<><CBAB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD>ţ<EFBFBD><C5A3>ֳ<EFBFBD>Ϊ<EFBFBD><CEAA>˫<EFBFBD><CBAB>ͨ<EFBFBD>ţ<EFBFBD>
3. ˫<><CBAB>ͬʱͨ<CAB1>ţ<EFBFBD><C5A3>ֳ<EFBFBD>Ϊȫ˫<C8AB><CBAB>ͨ<EFBFBD>š<EFBFBD>

## <20><>ͨ<EFBFBD><CDA8><EFBFBD><EFBFBD>

ģ<EFBFBD><EFBFBD><EFBFBD>ź<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>źţ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ź<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ɢ<EFBFBD><EFBFBD><EFBFBD>źš<EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD><EFBFBD><EFBFBD>ư<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ź<EFBFBD>ת<EFBFBD><EFBFBD>Ϊģ<EFBFBD><EFBFBD><EFBFBD>źš<EFBFBD>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/d2c55c84-aa1f-43c1-bd97-457bcb7816b3.png)

## <20>ŵ<EFBFBD><C5B5><EFBFBD><EFBFBD>ü<EFBFBD><C3BC><EFBFBD>

### 1. Ƶ<>ָ<EFBFBD><D6B8>á<EFBFBD>ʱ<EFBFBD>ָ<EFBFBD><D6B8><EFBFBD>

Ƶ<EFBFBD>ָ<EFBFBD><EFBFBD>õ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>û<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͬ<EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD>ռ<EFBFBD>ò<EFBFBD>ͬ<EFBFBD><EFBFBD>Ƶ<EFBFBD>ʴ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><EFBFBD>ʱ<EFBFBD>ָ<EFBFBD><EFBFBD>õ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>û<EFBFBD><EFBFBD>ڲ<EFBFBD>ͬ<EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD>ռ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͬ<EFBFBD><EFBFBD>Ƶ<EFBFBD>ʴ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><EFBFBD>

ʹ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ַ<EFBFBD>ʽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD>ţ<EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD>ŵĹ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>û<EFBFBD><EFBFBD><EFBFBD>һֱռ<EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ŵ<EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڼ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݵ<EFBFBD>ͻ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʣ<EFBFBD>û<EFBFBD><EFBFBD>Ҫһֱռ<EFBFBD><EFBFBD><EFBFBD>ŵ<EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ó<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>û<EFBFBD>ʹ<EFBFBD>ã<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ַ<EFBFBD>ʽ<EFBFBD><EFBFBD><EFBFBD>ŵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʶ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ߡ<EFBFBD>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/543d47a1-f0dd-414f-b23c-0c142c814854.png)

### 2. ͳ<><CDB3>ʱ<EFBFBD>ָ<EFBFBD><D6B8><EFBFBD>

<EFBFBD>Ƕ<EFBFBD>ʱ<EFBFBD>ָ<EFBFBD><EFBFBD>õ<EFBFBD>һ<EFBFBD>ָĽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̶<EFBFBD>ÿ<EFBFBD><EFBFBD><EFBFBD>û<EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD>ָ<EFBFBD><EFBFBD><EFBFBD>֡<EFBFBD>е<EFBFBD>λ<EFBFBD>ã<EFBFBD>ֻҪ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݾͼ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD>ָ<EFBFBD><EFBFBD><EFBFBD>֡Ȼ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>͡<EFBFBD>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/29058e09-bb72-4040-a73d-4c497895e9ce.jpg)

### 3. <20><><EFBFBD>ָ<EFBFBD><D6B8><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ƶ<EFBFBD>ָ<EFBFBD><EFBFBD>á<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڹ<EFBFBD><EFBFBD><EFBFBD>Ƶ<EFBFBD>ʺܸߣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϰ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ò<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ƶ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʾ<EFBFBD><EFBFBD>ʹ<EFBFBD>õĹ<EFBFBD><EFBFBD>ز<EFBFBD><EFBFBD><EFBFBD>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/78534153-88d1-4f83-a6e0-59064dbdc43a.png)

### 4. <20><><EFBFBD>ָ<EFBFBD><D6B8><EFBFBD>

Ϊÿ<EFBFBD><EFBFBD><EFBFBD>û<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> m bit <20><><EFBFBD><EFBFBD>Ƭ<EFBFBD><C6AC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>е<EFBFBD><D0B5><EFBFBD>Ƭ<EFBFBD><C6AC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ƭ $\vec{S}$ <20><> $\vec{T}$ <20><>

![](http://latex.codecogs.com/gif.latex?\\\\\vec{S}\cdot\vec{T}=0)

Ϊ<EFBFBD>˷<EFBFBD><EFBFBD>㣬ȡ m=8<><38><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ƭ $\vec{S}$ Ϊ 00011011<31><31><EFBFBD><EFBFBD>ӵ<EFBFBD>и<EFBFBD><D0B8><EFBFBD>Ƭ<EFBFBD><C6AC><EFBFBD>û<EFBFBD><C3BB><EFBFBD><EFBFBD>ͱ<EFBFBD><CDB1><EFBFBD> 1 ʱ<>ͷ<EFBFBD><CDB7>͸<EFBFBD><CDB8><EFBFBD>Ƭ<EFBFBD><C6AC><EFBFBD><EFBFBD><EFBFBD>ͱ<EFBFBD><CDB1><EFBFBD> 0 ʱ<>ͷ<EFBFBD><CDB7>͸<EFBFBD><CDB8><EFBFBD>Ƭ<EFBFBD>ķ<EFBFBD><C4B7><EFBFBD> 11100100<30><30>

<EFBFBD>ڼ<EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD> 00011011 <20><><EFBFBD><EFBFBD> (-1 -1 -1 +1 +1 -1 +1 +1)<29><><EFBFBD><EFBFBD><EFBFBD>Եõ<D4B5>

![](http://latex.codecogs.com/gif.latex?\\\\\frac{1}{m}\vec{S}\cdot\vec{S}=1)

![](http://latex.codecogs.com/gif.latex?\\\\\frac{1}{m}\vec{S}\cdot\vec{S'}=-1)

<EFBFBD><EFBFBD><EFBFBD><EFBFBD> $\vec{S'}$ Ϊ $\vec{S}$ <20>ķ<EFBFBD><C4B7>롣

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>֪<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ն<EFBFBD>ʹ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ƭ $\vec{S}$ <20>Խ<EFBFBD><D4BD>յ<EFBFBD><D5B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݽ<EFBFBD><DDBD><EFBFBD><EFBFBD>ڻ<EFBFBD><DABB><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ 0 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>û<EFBFBD><C3BB><EFBFBD><EFBFBD>͵<EFBFBD><CDB5><EFBFBD><EFBFBD>ݣ<EFBFBD><DDA3><EFBFBD><EFBFBD><EFBFBD>Ϊ 1 <20><><EFBFBD><EFBFBD><EFBFBD>û<EFBFBD><C3BB><EFBFBD><EFBFBD>͵ı<CDB5><C4B1><EFBFBD> 1<><31><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ -1 <20><><EFBFBD><EFBFBD><EFBFBD>û<EFBFBD><C3BB><EFBFBD><EFBFBD>͵ı<CDB5><C4B1><EFBFBD> 0<><30>

<EFBFBD><EFBFBD><EFBFBD>ָ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD><EFBFBD>͵<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊԭ<EFBFBD>ȵ<EFBFBD> m <20><><EFBFBD><EFBFBD>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/0042edad-8e3b-4279-bd93-6906fcd1b640.jpg)

# <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><C2B7>

## <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

### 1. <20><>װ<EFBFBD><D7B0>֡

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>㴫<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ķ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ײ<EFBFBD><EFBFBD><EFBFBD>β<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڱ<EFBFBD><EFBFBD><EFBFBD>֡<EFBFBD>Ŀ<EFBFBD>ʼ<EFBFBD>ͽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/ea5ed9b2-6d9f-48fb-b890-0288caf9088a.jpg)

### 2. ͸<><CDB8><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

͸<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʾһ<EFBFBD><EFBFBD>ʵ<EFBFBD>ʴ<EFBFBD><EFBFBD>ڵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>￴<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>񲻴<EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>

֡<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ײ<EFBFBD><EFBFBD><EFBFBD>β<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>֡<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݲ<EFBFBD><EFBFBD>ֺ<EFBFBD><EFBFBD>к<EFBFBD><EFBFBD>ײ<EFBFBD>β<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͬ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݣ<EFBFBD><EFBFBD><EFBFBD>ô֡<EFBFBD>Ŀ<EFBFBD>ʼ<EFBFBD>ͽ<EFBFBD><EFBFBD><EFBFBD>λ<EFBFBD>þͻᱻ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ж<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>г<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ײ<EFBFBD>β<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͬ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǰ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ת<EFBFBD><EFBFBD><EFBFBD>ַ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>þ<EFBFBD><EFBFBD><EFBFBD>ת<EFBFBD><EFBFBD><EFBFBD>ַ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ô<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ת<EFBFBD><EFBFBD><EFBFBD>ַ<EFBFBD>ǰ<EFBFBD><EFBFBD><EFBFBD>ټӸ<EFBFBD>ת<EFBFBD><EFBFBD><EFBFBD>ַ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڽ<EFBFBD><EFBFBD>ն˽<EFBFBD><EFBFBD>д<EFBFBD><EFBFBD><EFBFBD>֮<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ի<EFBFBD>ԭ<EFBFBD><EFBFBD>ԭʼ<EFBFBD><EFBFBD><EFBFBD>ݡ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>͸<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ת<EFBFBD><EFBFBD><EFBFBD>ַ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>û<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ת<EFBFBD><EFBFBD><EFBFBD>ַ<EFBFBD><EFBFBD>Ĵ<EFBFBD><EFBFBD>ڡ<EFBFBD>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/44e1d90e-3fe6-4dd6-8dce-6daab12e7663.jpg)

### 3. <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

Ŀǰ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><EFBFBD><EFBFBD>㷺ʹ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ѭ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>飨CRC<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ز<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

## <20><><EFBFBD>Ե<EFBFBD><D4B5>ŵ<EFBFBD> - PPP Э<><D0AD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>û<EFBFBD>ͨ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD><EFBFBD>ӵ<EFBFBD>ij<EFBFBD><EFBFBD> ISP ֮<><D6AE><EFBFBD><EFBFBD><EFBFBD>ܽ<EFBFBD><DCBD>뵽<EFBFBD><EBB5BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PPP Э<><D0AD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>û<EFBFBD><C3BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> ISP <20><><EFBFBD><EFBFBD>ͨ<EFBFBD><CDA8>ʱ<EFBFBD><CAB1>ʹ<EFBFBD>õ<EFBFBD><C3B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><C2B7>Э<EFBFBD>顣

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/8b5bd2c8-8425-4a8b-89db-235c95800de9.jpg)

<EFBFBD><EFBFBD> PPP <20><>֡<EFBFBD>У<EFBFBD>F <20>ֶ<EFBFBD>Ϊ֡<CEAA>Ķ<EFBFBD><C4B6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>A <20><> C <20><>ʱû<CAB1><C3BB><EFBFBD><EFBFBD><EFBFBD>塣FCS <20><>ʹ<EFBFBD><CAB9> CRC <20>ļ<EFBFBD><C4BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD>С<EFBFBD><D0A1><EFBFBD>Ϣ<EFBFBD><CFA2><EFBFBD>ֵij<D6B5><C4B3>Ȳ<EFBFBD><C8B2><EFBFBD><EFBFBD><EFBFBD> 1500<30><30>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/a5fa89e7-54b9-4e2f-8c48-a35712d7b2f5.jpg)

## <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/8b15e36f-69b4-46b6-a07c-7234ac7c7927.jpg)

## <20>㲥<EFBFBD>ŵ<EFBFBD> - CSMA/CD Э<><D0AD>*

<EFBFBD>ڹ㲥<EFBFBD>ŵ<EFBFBD><EFBFBD>ϣ<EFBFBD>ͬһʱ<EFBFBD><EFBFBD>ֻ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ̨<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݡ<EFBFBD>

CSMA/CD <20><>ʾ<EFBFBD>ز<EFBFBD><D8B2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> / <20><>ײ<EFBFBD><D7B2><EFBFBD>⡣

- **<2A><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>**<2A><>˵<EFBFBD><CBB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>磬<EFBFBD><E7A3AC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Զ<EFBFBD><D4B6><EFBFBD><EFBFBD>ķ<EFBFBD>ʽ<EFBFBD><CABD><EFBFBD>ӵ<EFBFBD><D3B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϡ<EFBFBD>
- **<2A>ز<EFBFBD><D8B2><EFBFBD><EFBFBD><EFBFBD>**<2A><>ÿ<EFBFBD><C3BF>վ<EFBFBD><D5BE><EFBFBD><EFBFBD><EFBFBD>벻ͣ<EBB2BB>ؼ<EFBFBD><D8BC><EFBFBD><EFBFBD>ŵ<EFBFBD><C5B5><EFBFBD><EFBFBD>ڷ<EFBFBD><DAB7><EFBFBD>ǰ<EFBFBD><C7B0><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ŵ<EFBFBD><C5B5><EFBFBD><EFBFBD><EFBFBD>ʹ<EFBFBD>ã<EFBFBD><C3A3>ͱ<EFBFBD><CDB1><EFBFBD><EFBFBD>ȴ<EFBFBD><C8B4><EFBFBD>
- **<2A><>ײ<EFBFBD><D7B2><EFBFBD><EFBFBD>**<2A><><EFBFBD>ڷ<EFBFBD><DAB7><EFBFBD><EFBFBD>У<EFBFBD><D0A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ŵ<EFBFBD><C5B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>վ<EFBFBD><D5BE><EFBFBD>ڷ<EFBFBD><DAB7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݣ<EFBFBD><DDA3>ͱ<EFBFBD>ʾ<EFBFBD><CABE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ײ<EFBFBD><D7B2><EFBFBD><EFBFBD>Ȼÿһ<C3BF><D2BB>վ<EFBFBD>ڷ<EFBFBD><DAB7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>֮ǰ<D6AE><C7B0><EFBFBD>Ѿ<EFBFBD><D1BE><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ŵ<EFBFBD>Ϊ<EFBFBD><CEAA><EFBFBD>У<EFBFBD><D0A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڵ<EFBFBD><DAB5>Ų<EFBFBD><C5B2>Ĵ<EFBFBD><C4B4><EFBFBD>ʱ<EFBFBD>ӵĴ<D3B5><C4B4>ڣ<EFBFBD><DAA3><EFBFBD><EFBFBD><EFBFBD><EFBFBD>п<EFBFBD><D0BF>ܻᷢ<DCBB><E1B7A2><EFBFBD><EFBFBD>ײ<EFBFBD><D7B2>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/f9ed4da5-0032-41e6-991a-36d995ec28fd.png)

<EFBFBD>Ƕ˵<EFBFBD><EFBFBD>˵Ĵ<EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD>Ϊ <20>ӣ<EFBFBD><D3A3><EFBFBD><EFBFBD>ȷ<EFBFBD><C8B7>͵<EFBFBD>վ<EFBFBD><D5BE><EFBFBD><EFBFBD><EFBFBD>ྭ<EFBFBD><E0BEAD> 2<><32> <20>Ϳ<EFBFBD><CDBF><EFBFBD>֪<EFBFBD><D6AA><EFBFBD>Ƿ<EFBFBD><C7B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ײ<EFBFBD><D7B2><EFBFBD><EFBFBD> 2<><32> Ϊ **<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>**<2A><>ֻ<EFBFBD>о<EFBFBD><D0BE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>֮<EFBFBD><D6AE><EFBFBD><EFBFBD>û<EFBFBD>м<EFBFBD><D0BC>⵽<EFBFBD><E2B5BD>ײ<EFBFBD><D7B2><EFBFBD><EFBFBD><EFBFBD>ܿ϶<DCBF><CFB6><EFBFBD><EFBFBD>η<EFBFBD><CEB7>Ͳ<EFBFBD><CDB2>ᷢ<EFBFBD><E1B7A2><EFBFBD><EFBFBD>ײ<EFBFBD><D7B2>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ײʱ<EFBFBD><EFBFBD>վ<EFBFBD><EFBFBD>Ҫֹͣ<EFBFBD><EFBFBD><EFBFBD>ͣ<EFBFBD><EFBFBD>ȴ<EFBFBD>һ<EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD>ٷ<EFBFBD><EFBFBD>͡<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> **<EFBFBD>ض϶<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ָ<EFBFBD><EFBFBD><EFBFBD>˱<EFBFBD><EFBFBD>㷨** <20><>ȷ<EFBFBD><C8B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ɢ<EFBFBD><C9A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> {0, 1, .., (2<sup>k</sup>-1)} <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȡ<EFBFBD><C8A1>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> r<><72>Ȼ<EFBFBD><C8BB>ȡ r <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD>ش<EFBFBD><D8B4>ȴ<EFBFBD>ʱ<EFBFBD>䡣

## <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

<EFBFBD>ӱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ͽ<EFBFBD><EFBFBD><EFBFBD>ʹ<EFBFBD>ü<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ľ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ǽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʹ<EFBFBD>õ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ģ<EFBFBD><EFBFBD>ʵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ߵĹ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>߼<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϵͳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͳ<EFBFBD><EFBFBD>̫<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>С<EFBFBD>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/897a4f4e-2683-44e1-a26a-c0d0234dc576.jpg)

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/40c3f8e5-3a20-45b6-a60c-77b9b952e104.jpg)

## MAC <20><>

MAC <20><>ַ<EFBFBD><D6B7> 6 <20>ֽڣ<D6BD>48 λ<><CEBB><EFBFBD>ĵ<EFBFBD>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ψһ<CEA8><D2BB>ʾ<EFBFBD><CABE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ̨<D2BB><CCA8><EFBFBD><EFBFBD>ӵ<EFBFBD>ж<EFBFBD><D0B6>ٸ<EFBFBD><D9B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ж<EFBFBD><D0B6>ٸ<EFBFBD> MAC <20><>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʼDZ<CABC><C7B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ձ<EFBFBD><D5B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/50d38e84-238f-4081-8876-14ef6d7938b5.jpg)

- **<2A><><EFBFBD><EFBFBD>**<2A><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϲ<EFBFBD>ʹ<EFBFBD>õ<EFBFBD>Э<EFBFBD>飻
- **<2A><><EFBFBD><EFBFBD>**<2A><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 46-1500 ֮<>䣬<EFBFBD><E4A3AC><EFBFBD><EFBFBD>̫С<CCAB><D0A1><EFBFBD><EFBFBD>Ҫ<EFBFBD><D2AA><EFBFBD>䣻
- **FCS**<2A><>֡<EFBFBD><D6A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>У<EFBFBD>ʹ<EFBFBD>õ<EFBFBD><C3B5><EFBFBD> CRC <20><><EFBFBD>鷽<EFBFBD><E9B7BD><EFBFBD><EFBFBD>
- **ǰͬ<C7B0><CDAC><EFBFBD><EFBFBD>**<2A><>ֻ<EFBFBD><D6BB>Ϊ<EFBFBD>˼<EFBFBD><CBBC><EFBFBD> FCS <20><>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD><EFBFBD>ģ<EFBFBD><C4A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>֮<EFBFBD><D6AE><EFBFBD>ᶪ<EFBFBD><E1B6AA><EFBFBD><EFBFBD>

## <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Խ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>λ<EFBFBD><EFBFBD><EFBFBD>޹ص<EFBFBD><EFBFBD>߼<EFBFBD><EFBFBD>飬ֻ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͬһ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>еij<EFBFBD>Ա<EFBFBD>Ż<EFBFBD><EFBFBD>յ<EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><EFBFBD><EFBFBD>㲥<EFBFBD><EFBFBD>Ϣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͼ<EFBFBD><EFBFBD> (A1, A2, A3, A4) <20><><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>A1 <20><><EFBFBD>͵Ĺ㲥<C4B9>ᱻ A2<41><32>A3<41><33>A4 <20>յ<EFBFBD><D5B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>վ<EFBFBD><D5BE><EFBFBD>ղ<EFBFBD><D5B2><EFBFBD><EFBFBD><EFBFBD>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/a74b70ac-323a-4b31-b4d5-90569b8a944b.png)

# <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>*

## <20><><EFBFBD><EFBFBD>Э<EFBFBD><D0AD> IP <20><><EFBFBD><EFBFBD>

<EFBFBD><EFBFBD>Ϊ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ĺ<EFBFBD><EFBFBD>ģ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ӧ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>㾡<EFBFBD><EFBFBD><EFBFBD>ܼ򵥡<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֻ<EFBFBD>ṩ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ġ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӵġ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ŭ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

ʹ<EFBFBD><EFBFBD> IP Э<>飬<EFBFBD><E9A3AC><EFBFBD>԰<EFBFBD><D4B0>칹<EFBFBD><ECB9B9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʹ<EFBFBD><CAB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>㿴<EFBFBD><E3BFB4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB>ͳһ<CDB3><D2BB><EFBFBD><EFBFBD><EFBFBD>硣

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/fe3d224c-8ffd-40f9-85b1-86ffe1393f6c.jpg)

<EFBFBD><EFBFBD> IP Э<><D0AD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʹ<EFBFBD>õĻ<C3B5><C4BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Э<EFBFBD>飺

1. <20><>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD>Э<EFBFBD><D0AD> ARP<52><50>Address Resolution Protocol<6F><6C>
2. <20><><EFBFBD>ʿ<EFBFBD><CABF>Ʊ<EFBFBD><C6B1><EFBFBD>Э<EFBFBD><D0AD> ICMP<4D><50>Internet Control Message Protocol<6F><6C>
3. <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Э<EFBFBD><D0AD> IGMP<4D><50>Internet Group Management Protocol<6F><6C>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/163cf8b4-5f30-46c9-af00-316a71b3c890.jpg)

## IP <20><><EFBFBD>ݱ<EFBFBD><DDB1><EFBFBD>ʽ

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/8681db55-0873-434b-aa98-83d07e8392ae.jpg)

- **<2A>汾** : <20><> 4<><34>IPv4<76><34><EFBFBD><EFBFBD> 6<><36>IPv6<76><36><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֵ<EFBFBD><D6B5>

- **<2A>ײ<EFBFBD><D7B2><EFBFBD><EFBFBD><EFBFBD>** : ռ 4 λ<><CEBB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֵΪ 15<31><35>ֵΪ 1 <20><>ʾ<EFBFBD><CABE><EFBFBD><EFBFBD> 1 <20><> 32 λ<>ֵij<D6B5><C4B3>ȣ<EFBFBD>Ҳ<EFBFBD><D2B2><EFBFBD><EFBFBD> 4 <20>ֽڡ<D6BD><DAA1><EFBFBD>Ϊ<EFBFBD>ײ<EFBFBD><D7B2>̶<EFBFBD><CCB6><EFBFBD><EFBFBD><EFBFBD>Ϊ 20 <20>ֽڣ<D6BD><DAA3><EFBFBD><EFBFBD>˸<EFBFBD>ֵ<EFBFBD><D6B5>СΪ 5<><35><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ѡ<EFBFBD><D1A1><EFBFBD>ֵij<D6B5><C4B3>Ȳ<EFBFBD><C8B2><EFBFBD> 4 <20>ֽڵ<D6BD><DAB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>β<EFBFBD><CEB2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>䲿<EFBFBD><E4B2BF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>䡣

- **<2A><><EFBFBD>ַ<EFBFBD><D6B7><EFBFBD>** : <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ø<EFBFBD><C3B8>õķ<C3B5><C4B7><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>²<EFBFBD>ʹ<EFBFBD>á<EFBFBD>

- **<2A>ܳ<EFBFBD><DCB3><EFBFBD>** : <20><><EFBFBD><EFBFBD><EFBFBD>ײ<EFBFBD><D7B2><EFBFBD><EFBFBD>Ⱥ<EFBFBD><C8BA><EFBFBD><EFBFBD>ݲ<EFBFBD><DDB2>ֳ<EFBFBD><D6B3>ȡ<EFBFBD>

- **<2A><>ʶ** : <20><><EFBFBD><EFBFBD><EFBFBD>ݱ<EFBFBD><DDB1><EFBFBD><EFBFBD>ȹ<EFBFBD><C8B9><EFBFBD><EFBFBD>Ӷ<EFBFBD><D3B6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ƭ<EFBFBD><C6AC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>£<EFBFBD><C2A3><EFBFBD>ͬ<EFBFBD><CDAC><EFBFBD>ݱ<EFBFBD><DDB1>IJ<EFBFBD>ͬ<EFBFBD><CDAC>Ƭ<EFBFBD><C6AC><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͬ<EFBFBD>ı<EFBFBD>ʶ<EFBFBD><CAB6><EFBFBD><EFBFBD>

- **Ƭƫ<C6AC><C6AB>** : <20>ͱ<EFBFBD>ʶ<EFBFBD><CAB6>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڷ<EFBFBD><DAB7><EFBFBD><EFBFBD><EFBFBD>Ƭ<EFBFBD><C6AC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ƭƫ<C6AC>Ƶĵ<C6B5>λΪ 8 <20>ֽڡ<D6BD>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/45c86855-9b18-4cf4-a9a7-f8b6eb78d133.png)

- **<2A><><EFBFBD><EFBFBD>ʱ<EFBFBD><CAB1>** <20><>TTL<54><4C><EFBFBD><EFBFBD><EFBFBD>Ĵ<EFBFBD><C4B4><EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD>˷<EFBFBD>ֹ<EFBFBD>޷<EFBFBD><DEB7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݱ<EFBFBD><DDB1>ڻ<EFBFBD><DABB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>в<EFBFBD><D0B2>϶<EFBFBD>Ȧ<EFBFBD>ӡ<EFBFBD><D3A1><EFBFBD>·<EFBFBD><C2B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD><CEAA>λ<EFBFBD><CEBB><EFBFBD><EFBFBD> TTL Ϊ 0 ʱ<>Ͷ<EFBFBD><CDB6><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݱ<EFBFBD><DDB1><EFBFBD>

- **Э<><D0AD>**<2A><>ָ<EFBFBD><D6B8>Я<EFBFBD><D0AF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ӧ<EFBFBD><D3A6><EFBFBD>Ͻ<EFBFBD><CFBD><EFBFBD><EFBFBD>ĸ<EFBFBD>Э<EFBFBD><D0AD><EFBFBD><EFBFBD><EFBFBD>д<EFBFBD><D0B4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> ICMP<4D><50>TCP<43><50>UDP <20>ȡ<EFBFBD>

- **<2A>ײ<EFBFBD><D7B2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>**<2A><><EFBFBD><EFBFBD>Ϊ<EFBFBD><CEAA><EFBFBD>ݱ<EFBFBD>ÿ<EFBFBD><C3BF><EFBFBD><EFBFBD>һ<EFBFBD><D2BB>·<EFBFBD><C2B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><D2AA><EFBFBD>¼<EFBFBD><C2BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͣ<EFBFBD><CDA3><EFBFBD><EFBFBD>˼<EFBFBD><CBBC><EFBFBD><EFBFBD>Ͳ<EFBFBD><CDB2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݲ<EFBFBD><DDB2>ֿ<EFBFBD><D6BF>Լ<EFBFBD><D4BC>ټ<EFBFBD><D9BC><EFBFBD><EFBFBD>Ĺ<EFBFBD><C4B9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

## IP <20><>ַ<EFBFBD><D6B7>ַ

IP <20><>ַ<EFBFBD>ı<EFBFBD>ַ<EFBFBD><D6B7>ʽ<EFBFBD><CABD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʷ<EFBFBD>׶Σ<D7B6>

1. <20><><EFBFBD>ࣻ
2. <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>֣<EFBFBD>
3. <20>޷<EFBFBD><DEB7>ࡣ

### 1. <20><><EFBFBD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ɣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ź<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ţ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>в<EFBFBD>ͬ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>в<EFBFBD>ͬ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ų<EFBFBD><EFBFBD>ȣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǹ̶<EFBFBD><EFBFBD>ġ<EFBFBD>

IP <20><>ַ ::= {< <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> >, < <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> >}

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/2ddd6132-60be-4a72-9daa-3d9756191f4a.png)

### 2. <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

ͨ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֶ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ţ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> IP <20><>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD>Ϊ<EFBFBD><CEAA><EFBFBD><EFBFBD> IP <20><>ַ<EFBFBD><D6B7>ע<EFBFBD>⣬<EFBFBD>ⲿ<EFBFBD><E2B2BF><EFBFBD>翴<EFBFBD><E7BFB4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ĵ<EFBFBD><C4B4>ڡ<EFBFBD>

IP <20><>ַ ::= {< <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> >, < <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> >, < <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> >}

Ҫʹ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>롣һ<EFBFBD><EFBFBD> B <20><><EFBFBD><EFBFBD>ַ<EFBFBD><D6B7>Ĭ<EFBFBD><C4AC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ 255.255.0.0<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> B <20><><EFBFBD><EFBFBD>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ռ<EFBFBD><D5BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>أ<EFBFBD><D8A3><EFBFBD>ô<EFBFBD><C3B4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ 11111111 11111111 11000000 000000<30><30>Ҳ<EFBFBD><D2B2><EFBFBD><EFBFBD> 255.255.192.0<EFBFBD><EFBFBD>

### 3. <20>޷<EFBFBD><DEB7><EFBFBD>

<EFBFBD>޷<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ַ CIDR <20><><EFBFBD><EFBFBD><EFBFBD>˴<EFBFBD>ͳ A <20>ࡢB <20><><EFBFBD><EFBFBD> C <20><><EFBFBD><EFBFBD>ַ<EFBFBD>Լ<EFBFBD><D4BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ĸ<EFBFBD><C4B8>ʹ<EEA3AC><CAB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǰ׺<C7B0><D7BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> IP <20><>ַ<EFBFBD><D6B7><EFBFBD>б<EFBFBD><D0B1>룬<EFBFBD><EBA3AC><EFBFBD><EFBFBD>ǰ׺<C7B0>ij<EFBFBD><C4B3>ȿ<EFBFBD><C8BF>Ը<EFBFBD><D4B8><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD>仯<EFBFBD><E4BBAF>

IP <20><>ַ ::= {< <20><><EFBFBD><EFBFBD>ǰ׺<C7B0><D7BA> >, < <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> >}

CIDR <20>ļǷ<C4BC><C7B7>ϲ<EFBFBD><CFB2><EFBFBD><EFBFBD><EFBFBD> IP <20><>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǰ׺<C7B0><D7BA><EFBFBD>ȵķ<C8B5><C4B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 128.14.35.7/20 <20><>ʾǰ 20 λΪ<CEBB><CEAA><EFBFBD><EFBFBD>ǰ׺<C7B0><D7BA>

CIDR <20>ĵ<EFBFBD>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Լ<EFBFBD><D4BC><EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD><CEAA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>룬<EFBFBD><EBA3AC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 1 <20><><EFBFBD><EFBFBD>Ϊ<EFBFBD><CEAA><EFBFBD><EFBFBD>ǰ׺<C7B0>ij<EFBFBD><C4B3>ȡ<EFBFBD>

һ<EFBFBD><EFBFBD> CIDR <20><>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD><EFBFBD>кܶ<D0BA><DCB6><EFBFBD>ַ<EFBFBD><D6B7>һ<EFBFBD><D2BB> CIDR <20><>ʾ<EFBFBD><CABE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϳ<EFBFBD><CDBF>Ա<EFBFBD>ʾԭ<CABE><D4AD><EFBFBD>ĺܶ<C4BA><DCB6><EFBFBD><EFBFBD><EFBFBD><EFBFBD>磬<EFBFBD><E7A3AC><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD>ɱ<EFBFBD><C9B1><EFBFBD>ֻ<EFBFBD><D6BB>Ҫһ<D2AA><D2BB>·<EFBFBD>ɾͿ<C9BE><CDBF>Դ<EFBFBD><D4B4><EFBFBD>ԭ<EFBFBD><D4AD><EFBFBD>Ķ<EFBFBD><C4B6><EFBFBD>·<EFBFBD>ɣ<EFBFBD><C9A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD>ɱ<EFBFBD><C9B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD><CDA8>ʹ<EFBFBD><CAB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǰ׺<C7B0><D7BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD>ɱ<EFBFBD><C9B1><EFBFBD><EFBFBD>ķ<EFBFBD>ʽ<EFBFBD><CABD>Ϊ·<CEAA>ɾۺϣ<DBBA>Ҳ<EFBFBD><D2B2>Ϊ **<EFBFBD><EFBFBD><EFBFBD>ɳ<EFBFBD><EFBFBD><EFBFBD>**<2A><>

<EFBFBD><EFBFBD>·<EFBFBD>ɱ<EFBFBD><EFBFBD>е<EFBFBD><EFBFBD><EFBFBD>Ŀ<EFBFBD>ɡ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǰ׺<EFBFBD><EFBFBD><EFBFBD>͡<EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ַ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ɣ<EFBFBD><EFBFBD>ڲ<EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD>ܻ<EFBFBD><EFBFBD>õ<EFBFBD><EFBFBD><EFBFBD>ֹһ<EFBFBD><EFBFBD>ƥ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ӧ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǰ׺ƥ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȷ<EFBFBD><EFBFBD>Ӧ<EFBFBD><EFBFBD>ƥ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>

## IP <20><>ַ<EFBFBD><D6B7> MAC <20><>ַ

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>֮<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD>ţ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><EFBFBD>ʵ<EFBFBD>־<EFBFBD><EFBFBD><EFBFBD>ÿ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>·֮<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD>š<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD>Ź<EFBFBD><EFBFBD><EFBFBD><EFBFBD>У<EFBFBD>IP <20><><EFBFBD>ݱ<EFBFBD><DDB1><EFBFBD>Դ<EFBFBD><D4B4>ַ<EFBFBD><D6B7>Ŀ<EFBFBD>ĵ<EFBFBD>ַʼ<D6B7>ղ<EFBFBD><D5B2>䣬<EFBFBD><E4A3AC> MAC <20><>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD>ĸı<C4B8><C4B1><EFBFBD><EFBFBD>ı䡣

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/86b71296-0d1e-4a63-bcd9-54955b6b781b.jpg)

## <20><>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD>Э<EFBFBD><D0AD> ARP

ʵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD> IP <20><>ַ<EFBFBD>õ<EFBFBD> MAC <20><>ַ<EFBFBD><D6B7>

ÿ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD> ARP <20><><EFBFBD>ٻ<EFBFBD><D9BB>棬<EFBFBD><E6A3AC><EFBFBD><EFBFBD>ӳ<EFBFBD><D3B3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB> IP <20><>ַ<EFBFBD><D6B7> MAC <20><>ַ<EFBFBD><D6B7>ӳ<EFBFBD>䲻<EFBFBD>ڸñ<DAB8><C3B1>У<EFBFBD><D0A3><EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD><CDA8><EFBFBD>㲥<EFBFBD>ķ<EFBFBD>ʽ<EFBFBD><CABD><EFBFBD><EFBFBD> ARP <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>飬ƥ<E9A3AC><C6A5> IP <20><>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ᷢ<EFBFBD><E1B7A2> ARP <20><>Ӧ<EFBFBD><D3A6><EFBFBD><EFBFBD><EFBFBD><EFBFBD>֪<EFBFBD><D6AA> MAC <20><>ַ<EFBFBD><D6B7>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/8bc6fc2c-d198-4759-b06c-18d94d851e97.png)

## ·<><C2B7><EFBFBD><EFBFBD><EFBFBD>Ľṹ

·<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӹ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ͽ<EFBFBD><EFBFBD>Ի<EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD><EFBFBD><EFBFBD>󲿷֣<EFBFBD>·<EFBFBD><EFBFBD>ѡ<EFBFBD><EFBFBD><EFBFBD>ͷ<EFBFBD><EFBFBD><EFBFBD>ת<EFBFBD><EFBFBD><EFBFBD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ת<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ɣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ṹ<EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>˿ں<EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>˿ڡ<EFBFBD>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/3a676c54-b559-4466-9b21-eb10f1e25879.jpg)

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ṹ<EFBFBD>Ľ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʵ<EFBFBD>ַ<EFBFBD>ʽ<EFBFBD><EFBFBD>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/7f82fd18-7f16-4125-ada6-bb6b795b4fda.png)

## <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><C2B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

- <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD>㣬<EFBFBD><E3A3AC>ʶ<EFBFBD><CAB6> MAC <20><>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD> MAC <20><>ַת<D6B7><D7AA><EFBFBD><EFBFBD>·<EFBFBD><C2B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>֡<EFBFBD><D6A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ѧ<EFBFBD><D1A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ά<EFBFBD><CEAC> IP <20><>ַ<EFBFBD><D6B7> MAC <20><>ַ<EFBFBD><D6B7>ӳ<EFBFBD>䡣

- ·<><C2B7><EFBFBD><EFBFBD>λ<EFBFBD><CEBB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>㣬<EFBFBD><E3A3AC>ʶ<EFBFBD><CAB6> IP <20><>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD> IP <20><>ַת<D6B7><D7AA><EFBFBD><EFBFBD><EFBFBD>顣ά<E9A1A3><CEAC><EFBFBD><EFBFBD>·<EFBFBD>ɱ<EFBFBD><C9B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD>ɱ<EFBFBD>ѡ<EFBFBD><D1A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD>ߡ<EFBFBD>

## ·<><C2B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ת<EFBFBD><D7AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

1. <20><><EFBFBD><EFBFBD><EFBFBD>ݱ<EFBFBD><DDB1><EFBFBD><EFBFBD>ײ<EFBFBD><D7B2><EFBFBD>ȡĿ<C8A1><C4BF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> IP <20><>ַ D<><44><EFBFBD>õ<EFBFBD>Ŀ<EFBFBD><C4BF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ַ N<><4E><EFBFBD><EFBFBD>·<EFBFBD>ɱ<EFBFBD><C9B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ŷ<EFBFBD><C5B6><EFBFBD><EFBFBD><EFBFBD> IP <20><>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD>ɱ<EFBFBD><C9B1><EFBFBD>Ŀ<EFBFBD><C4BF><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
2. <20><> N <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><C2B7><EFBFBD><EFBFBD>ֱ<EFBFBD><D6B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ij<EFBFBD><C4B3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֱ<EFBFBD>ӽ<EFBFBD><D3BD><EFBFBD><EFBFBD><EFBFBD>
3. <20><>·<EFBFBD>ɱ<EFBFBD><C9B1><EFBFBD><EFBFBD><EFBFBD>Ŀ<EFBFBD>ĵ<EFBFBD>ַΪ D <20><><EFBFBD>ض<EFBFBD><D8B6><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD>ɣ<EFBFBD><C9A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݱ<EFBFBD><DDB1><EFBFBD><EFBFBD>͸<EFBFBD><CDB8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ָ<EFBFBD><D6B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB>·<EFBFBD><C2B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
4. <20><>·<EFBFBD>ɱ<EFBFBD><C9B1><EFBFBD><EFBFBD>е<EFBFBD><D0B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> N <20><>·<EFBFBD>ɣ<EFBFBD><C9A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݱ<EFBFBD><DDB1><EFBFBD><EFBFBD>͸<EFBFBD>·<EFBFBD>ɱ<EFBFBD><C9B1><EFBFBD><EFBFBD><EFBFBD>ָ<EFBFBD><D6B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB>·<EFBFBD><C2B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
5. <20><>·<EFBFBD>ɱ<EFBFBD><C9B1><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB>Ĭ<EFBFBD><C4AC>·<EFBFBD>ɣ<EFBFBD><C9A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݱ<EFBFBD><DDB1><EFBFBD><EFBFBD>͸<EFBFBD>·<EFBFBD>ɱ<EFBFBD><C9B1><EFBFBD><EFBFBD><EFBFBD>ָ<EFBFBD><D6B8><EFBFBD><EFBFBD>Ĭ<EFBFBD><C4AC>·<EFBFBD><C2B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
6. <20><><EFBFBD><EFBFBD>ת<EFBFBD><D7AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/8d211911-0e62-4190-ab00-d8610adec4a0.jpg)

## ·<><C2B7>ѡ<EFBFBD><D1A1>Э<EFBFBD><D0AD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʹ<EFBFBD>õ<EFBFBD>·<EFBFBD><EFBFBD>ѡ<EFBFBD><EFBFBD>Э<EFBFBD>鶼<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ӧ<EFBFBD>ģ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>˱仯<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ӧ<EFBFBD>ؽ<EFBFBD><EFBFBD>е<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ի<EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>С<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϵͳ AS<41><53>һ<EFBFBD><D2BB> AS <20><><EFBFBD><EFBFBD>ʹ<EFBFBD><CAB9>һ<EFBFBD>ֺͱ<D6BA><CDB1><EFBFBD> AS <20><>ͬ<EFBFBD><CDAC>·<EFBFBD><C2B7>ѡ<EFBFBD><D1A1>Э<EFBFBD>顣

<EFBFBD><EFBFBD><EFBFBD>԰<EFBFBD>·<EFBFBD><EFBFBD>ѡ<EFBFBD><EFBFBD>Э<EFBFBD>黮<EFBFBD><EFBFBD>Ϊ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ࣺ

1. <20>ڲ<EFBFBD><DAB2><EFBFBD><EFBFBD><EFBFBD>Э<EFBFBD><D0AD> IGP<47><50>Interior Gateway Protocol<6F><6C> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϵͳ<CFB5>ڲ<EFBFBD>ʹ<EFBFBD>ã<EFBFBD><C3A3><EFBFBD> RIP <20><> OSPF<50><46>
2. <20>ⲿ<EFBFBD><E2B2BF><EFBFBD><EFBFBD>Э<EFBFBD><D0AD> EGP<47><50>External Gateway Protocol<6F><6C> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϵͳ֮<CDB3><D6AE>ʹ<EFBFBD>ã<EFBFBD><C3A3><EFBFBD> BGP<47><50>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/e0be6970-5b0e-44a2-bc71-df4d61c42b8f.jpg)

### 1. <20>ڲ<EFBFBD><DAB2><EFBFBD><EFBFBD><EFBFBD>Э<EFBFBD><D0AD> RIP

RIP <20><>һ<EFBFBD>ֲַ<D6B7>ʽ<EFBFBD>Ļ<EFBFBD><C4BB>ھ<EFBFBD><DABE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><C2B7>ѡ<EFBFBD><D1A1>Э<EFBFBD>顣<EFBFBD><E9A1A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ָ<EFBFBD><D6B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֱ<EFBFBD><D6B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><C2B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ 1<><31><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ 15<31><35><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 15 <20><>ʾ<EFBFBD><CABE><EFBFBD>ɴ

RIP <20><><EFBFBD>̶<EFBFBD><CCB6><EFBFBD>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><C2B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Լ<EFBFBD><D4BC><EFBFBD>·<EFBFBD>ɱ<EFBFBD><C9B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ɴν<C9B4><CEBD><EFBFBD>֮<EFBFBD><D6AE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><C2B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ջ<EFBFBD>֪<EFBFBD><D6AA><EFBFBD><EFBFBD><EFBFBD>ﱾ<EFBFBD><EFB1BE><EFBFBD><EFBFBD>ϵͳ<CFB5><CDB3><EFBFBD>κ<EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̾<EFBFBD><CCBE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB>·<EFBFBD><C2B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ַ<EFBFBD><D6B7>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>㷨<EFBFBD><EFBFBD>

1. <20>Ե<EFBFBD>ַΪ X <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><C2B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> RIP <20><><EFBFBD>ģ<EFBFBD><C4A3><EFBFBD><EFBFBD>޸ı<DEB8><C4B1><EFBFBD><EFBFBD>е<EFBFBD><D0B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ŀ<EFBFBD><C4BF><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD>ֶ<EFBFBD><D6B6>еĵ<D0B5>ַ<EFBFBD><D6B7>Ϊ X<><58><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>еľ<D0B5><C4BE><EFBFBD><EFBFBD>ֶμ<D6B6> 1<><31>
2. <20><><EFBFBD>޸ĺ<DEB8><C4BA><EFBFBD> RIP <20><><EFBFBD><EFBFBD><EFBFBD>е<EFBFBD>ÿһ<C3BF><D2BB><EFBFBD><EFBFBD>Ŀ<EFBFBD><C4BF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>²<EFBFBD><C2B2>裺
 - <20><>ԭ<EFBFBD><D4AD><EFBFBD><EFBFBD>·<EFBFBD>ɱ<EFBFBD><C9B1><EFBFBD>û<EFBFBD><C3BB>Ŀ<EFBFBD><C4BF><EFBFBD><EFBFBD><EFBFBD><EFBFBD> N<><4E><EFBFBD><EFBFBD><EFBFBD>Ѹ<EFBFBD><D1B8><EFBFBD>Ŀ<EFBFBD><C4BF><EFBFBD>ӵ<EFBFBD>·<EFBFBD>ɱ<EFBFBD><C9B1>У<EFBFBD>
 - <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB>·<EFBFBD><C2B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ַ<EFBFBD><D6B7> X<><58><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>յ<EFBFBD><D5B5><EFBFBD><EFBFBD><EFBFBD>Ŀ<EFBFBD>滻ԭ<E6BBBB><D4AD>·<EFBFBD>ɱ<EFBFBD><C9B1>е<EFBFBD><D0B5><EFBFBD>Ŀ<EFBFBD><C4BF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>յ<EFBFBD><D5B5><EFBFBD><EFBFBD><EFBFBD>Ŀ<EFBFBD>еľ<D0B5><C4BE><EFBFBD> d С<><D0A1>·<EFBFBD>ɱ<EFBFBD><C9B1>еľ<D0B5><C4BE>룬<EFBFBD><EBA3AC><EFBFBD><EFBFBD><EFBFBD>и<EFBFBD><D0B8>£<EFBFBD><C2A3><EFBFBD><EFBFBD><EFBFBD>ԭʼ·<CABC>ɱ<EFBFBD><C9B1><EFBFBD>Ϊ Net2, 5, P<><50><EFBFBD>±<EFBFBD><C2B1><EFBFBD>Ϊ Net2, 4, X<><58><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>£<EFBFBD><C2A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʲôҲ<C3B4><D2B2><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
3. <20><> 3 <20><><EFBFBD>ӻ<EFBFBD>û<EFBFBD><C3BB><EFBFBD>յ<EFBFBD><D5B5><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><C2B7><EFBFBD><EFBFBD><EFBFBD>ĸ<EFBFBD><C4B8><EFBFBD>·<EFBFBD>ɱ<EFBFBD><C9B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ѹ<EFBFBD><D1B8><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><C2B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD><CEAA><EFBFBD>ɴ<C9B4><EFA3AC><EFBFBD>Ѿ<EFBFBD><D1BE><EFBFBD><EFBFBD><EFBFBD>Ϊ 16<31><36>

RIP Э<><D0AD>ʵ<EFBFBD>ּ򵥣<D6BC><F2B5A5A3><EFBFBD><EFBFBD><EFBFBD>С<EFBFBD><D0A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD> RIP <20><>ʹ<EFBFBD>õ<EFBFBD><C3B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ 15<31><35><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ĺ<EFBFBD>ģ<EFBFBD><C4A3><EFBFBD><EFBFBD><EFBFBD>ҵ<EFBFBD><D2B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֹ<EFBFBD><D6B9><EFBFBD>ʱ<EFBFBD><CAB1>Ҫ<EFBFBD><D2AA><EFBFBD><EFBFBD><EFBFBD>Ƚϳ<C8BD><CFB3><EFBFBD>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD><EFBFBD>ܽ<EFBFBD><DCBD><EFBFBD><EFBFBD><EFBFBD>Ϣ<EFBFBD><CFA2><EFBFBD>͵<EFBFBD><CDB5><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><C2B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

### 2. <20>ڲ<EFBFBD><DAB2><EFBFBD><EFBFBD><EFBFBD>Э<EFBFBD><D0AD> OSPF

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> OSPF<50><46><EFBFBD><EFBFBD>Ϊ<EFBFBD>˿˷<CBBF> RIP <20><>ȱ<EFBFBD><C8B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ġ<EFBFBD>

<EFBFBD><EFBFBD><EFBFBD>ű<EFBFBD>ʾ OSPF <20><><EFBFBD><EFBFBD>ijһ<C4B3>ҳ<EFBFBD><D2B3>̿<EFBFBD><CCBF>ƣ<EFBFBD><C6A3><EFBFBD><EFBFBD>ǹ<EFBFBD><C7B9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ģ<EFBFBD><C4A3><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><C2B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊʹ<CEAA><CAB9><EFBFBD><EFBFBD> Dijkstra <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><C2B7><EFBFBD>㷨 SPF<50><46>

OSPF <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ص㣺

1. <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϵͳ<CFB5>е<EFBFBD><D0B5><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><C2B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϣ<EFBFBD><CFA2><EFBFBD><EFBFBD><EFBFBD>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD>Ǻ鷺<C7BA><E9B7BA><EFBFBD><EFBFBD>
2. <20><><EFBFBD>͵<EFBFBD><CDB5><EFBFBD>Ϣ<EFBFBD><CFA2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><C2B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·״̬<D7B4><CCAC><EFBFBD><EFBFBD>·״̬<D7B4><CCAC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Щ·<D0A9><C2B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Լ<EFBFBD><D4BC><EFBFBD>·<EFBFBD>Ķ<EFBFBD><C4B6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>÷<EFBFBD><C3B7>á<EFBFBD><C3A1><EFBFBD><EFBFBD>롢ʱ<EBA1A2>ӡ<EFBFBD><D3A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʾ<EFBFBD><CABE>
3. ֻ<>е<EFBFBD><D0B5><EFBFBD>·״̬<D7B4><CCAC><EFBFBD><EFBFBD><EFBFBD>仯ʱ<E4BBAF><CAB1>·<EFBFBD><C2B7><EFBFBD><EFBFBD><EFBFBD>Żᷢ<C5BB><E1B7A2><EFBFBD><EFBFBD>Ϣ<EFBFBD><CFA2>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȫ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>˽ṹͼ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD>µġ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> RIP<49><50>OSPF <20>ĸ<EFBFBD><C4B8>¹<EFBFBD><C2B9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ĺܿ졣

### 3. <20>ⲿ<EFBFBD><E2B2BF><EFBFBD><EFBFBD>Э<EFBFBD><D0AD> BGP

AS ֮<><D6AE><EFBFBD><EFBFBD>·<EFBFBD><C2B7>ѡ<EFBFBD><D1A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ѣ<EFBFBD><D1A3><EFBFBD>Ҫ<EFBFBD>ǻ<EFBFBD><C7BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ģ<EFBFBD>ܴ󡣲<DCB4><F3A1A3B2>Ҹ<EFBFBD><D2B8><EFBFBD> AS <20>ڲ<EFBFBD>ʹ<EFBFBD>ò<EFBFBD>ͬ<EFBFBD><CDAC>·<EFBFBD><C2B7>ѡ<EFBFBD><D1A1>Э<EFBFBD>飬<EFBFBD><E9A3AC><EFBFBD>޷<EFBFBD>׼ȷ<D7BC><C8B7><EFBFBD><EFBFBD>·<EFBFBD><C2B7><EFBFBD>Ķ<EFBFBD><C4B6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> AS ֮<><D6AE><EFBFBD><EFBFBD>·<EFBFBD><C2B7>ѡ<EFBFBD><D1A1><EFBFBD><EFBFBD><EFBFBD>뿼<EFBFBD><EBBFBC><EFBFBD>йصIJ<D8B5><C4B2>ԣ<EFBFBD><D4A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Щ AS <20><>Ը<EFBFBD><D4B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> AS <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

BGP ֻ<><D6BB>Ѱ<EFBFBD><D1B0>һ<EFBFBD><D2BB><EFBFBD>ȽϺõ<CFBA>·<EFBFBD>ɣ<EFBFBD><C9A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD>ɡ<EFBFBD><C9A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><C2B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><C2B7>ѡ<EFBFBD><D1A1>Э<EFBFBD>顣

ÿ<EFBFBD><EFBFBD> AS <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> BGP <20><><EFBFBD><EFBFBD><EFBFBD>ˣ<EFBFBD>ͨ<EFBFBD><CDA8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> BGP <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>֮<EFBFBD>佨<EFBFBD><E4BDA8> TCP <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><C2B7><EFBFBD><EFBFBD>Ϣ<EFBFBD><CFA2>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/eb6271de-22c9-4f4b-8b31-eab1f560efac.png)

## <20><><EFBFBD>ʿ<EFBFBD><CABF>Ʊ<EFBFBD><C6B1><EFBFBD>Э<EFBFBD><D0AD> ICMP

ICMP <20><>Ϊ<EFBFBD>˸<EFBFBD><CBB8><EFBFBD>Ч<EFBFBD><D0A7>ת<EFBFBD><D7AA> IP <20><><EFBFBD>ݱ<EFBFBD><DDB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>߽<EFBFBD><DFBD><EFBFBD><EFBFBD>ɹ<EFBFBD><C9B9>Ļ<EFBFBD><C4BB>ᡣ<EFBFBD><E1A1A3><EFBFBD><EFBFBD>װ<EFBFBD><D7B0> IP <20><><EFBFBD>ݱ<EFBFBD><DDB1>У<EFBFBD><D0A3><EFBFBD><EFBFBD>Dz<EFBFBD><C7B2><EFBFBD><EFBFBD>ڸ߲<DAB8>Э<EFBFBD>顣

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/9b5e0fa0-9274-4219-a3a9-84fbb509c735.jpg)

ICMP <20><><EFBFBD>ķ<EFBFBD>Ϊ<EFBFBD><CEAA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>汨<EFBFBD>ĺ<EFBFBD>ѯ<EFBFBD>ʱ<EFBFBD><CAB1>ġ<EFBFBD>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/6e11b122-95ce-4869-bf7d-3b0d7591707e.jpg)

## <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̽<EFBFBD><CCBD> PING

PING <20><> ICMP <20><>һ<EFBFBD><D2BB><EFBFBD><EFBFBD>ҪӦ<D2AA>ã<EFBFBD><C3A3><EFBFBD>Ҫ<EFBFBD><D2AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̨<EFBFBD><CCA8><EFBFBD><EFBFBD>֮<EFBFBD><D6AE><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD>ԡ<EFBFBD>

PING <20>Ĺ<EFBFBD><C4B9>̣<EFBFBD>

1. PING ͬһ<CDAC><D2BB><EFBFBD><EFBFBD><EFBFBD>ε<EFBFBD><CEB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ŀ<EFBFBD><C4BF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> MAC <20><>ַ<EFBFBD><D6B7>Ȼ<EFBFBD><C8BB>ֱ<EFBFBD>ӽ<EFBFBD><D3BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>޷<EFBFBD><DEB7><EFBFBD><EFBFBD>ҵ<EFBFBD> MAC <20><>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD>Ҫ<EFBFBD><D2AA><EFBFBD><EFBFBD>һ<EFBFBD><D2BB> ARP <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
2. PING <20><>ͬ<EFBFBD><CDAC><EFBFBD>ε<EFBFBD><CEB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͷ<EFBFBD><CDB7>͸<EFBFBD><CDB8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ת<EFBFBD><D7AA><EFBFBD><EFBFBD>ͬ<EFBFBD><CDAC>Ҫ<EFBFBD><D2AA><EFBFBD>͸<EFBFBD><CDB8><EFBFBD><EFBFBD><EFBFBD>Ҳ<EFBFBD><D2B2>Ҫͨ<D2AA><CDA8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ص<EFBFBD> MAC <20><>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD> MAC <20><>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD>ת<EFBFBD><D7AA><EFBFBD><EFBFBD>

## IP <20>ಥ

<EFBFBD><EFBFBD>һ<EFBFBD>Զ<EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD><EFBFBD><EFBFBD>У<EFBFBD><EFBFBD>ಥ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>鸴<EFBFBD>ƶ<EFBFBD><EFBFBD>ݣ<EFBFBD><EFBFBD>Ӷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Լ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><EFBFBD>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/c77b6a18-dfac-42a2-ac89-7e99481275dc.jpg)

## <20><><EFBFBD><EFBFBD>ר<EFBFBD><D7A8><EFBFBD><EFBFBD> VPN

<EFBFBD><EFBFBD><EFBFBD><EFBFBD> IP <20><>ַ<EFBFBD>Ľ<EFBFBD>ȱ<EFBFBD><C8B1>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>뵽<EFBFBD><EBB5BD> IP <20><>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ԶС<D4B6>ڱ<EFBFBD><DAB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӵ<EFBFBD>е<EFBFBD><D0B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><D2AA><EFBFBD><EFBFBD><EFBFBD>е<EFBFBD><D0B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>뵽<EFBFBD>ⲿ<EFBFBD>Ļ<EFBFBD><C4BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>У<EFBFBD><D0A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڵļ<DAB5><C4BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʹ<EFBFBD>ý<EFBFBD><C3BD>ڱ<EFBFBD><DAB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ч<EFBFBD><D0A7> IP <20><>ַ<EFBFBD><D6B7>ר<EFBFBD>õ<EFBFBD>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ר<EFBFBD>õ<EFBFBD>ַ<EFBFBD>飺

1. 10.0.0.0 \~ 10.255.255.255
2. 172.16.0.0 \~ 172.31.255.255
3. 192.168.0.0 \~ 192.168.255.255

VPN ʹ<>ù<EFBFBD><C3B9>õĻ<C3B5><C4BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD><CEAA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ר<EFBFBD><D7A8><EFBFBD><EFBFBD>֮<EFBFBD><D6AE><EFBFBD><EFBFBD>ͨ<EFBFBD><CDA8><EFBFBD><EFBFBD><EFBFBD>塣ר<E5A1A3><D7A8>ָ<EFBFBD><D6B8><EFBFBD><EFBFBD><EFBFBD>ڵ<EFBFBD><DAB5><EFBFBD><EFBFBD><EFBFBD>ֻ<EFBFBD>뱾<EFBFBD><EBB1BE><EFBFBD><EFBFBD><EFBFBD>ڵ<EFBFBD><DAB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD>ţ<EFBFBD><C5A3><EFBFBD><EFBFBD><EFBFBD>ָ<EFBFBD><D6B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǡ<EFBFBD><C7A1><EFBFBD><EFBFBD><EFBFBD>ʵ<EFBFBD><CAB5><EFBFBD>ϲ<EFBFBD><CFB2><EFBFBD><EFBFBD>ǣ<EFBFBD><C7A3><EFBFBD><EFBFBD>о<EFBFBD><D0BE><EFBFBD><EFBFBD><EFBFBD><EFBFBD>õĻ<C3B5><C4BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

<EFBFBD><EFBFBD>ͼ<EFBFBD>У<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> A <20><> B <20><>ͨ<EFBFBD>Ų<EFBFBD><C5B2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> A <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> X Ҫ<><D2AA><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD> B <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Y ͨ<>ţ<EFBFBD>IP <20><><EFBFBD>ݱ<EFBFBD><DDB1><EFBFBD>Դ<EFBFBD><D4B4>ַ<EFBFBD><D6B7> 10.1.0.1<EFBFBD><EFBFBD>Ŀ<EFBFBD>ĵ<EFBFBD>ַ<EFBFBD><EFBFBD> 10.2.0.3<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݱ<EFBFBD><EFBFBD>ȷ<EFBFBD><EFBFBD>͵<EFBFBD><EFBFBD>뻥<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>·<EFBFBD><EFBFBD><EFBFBD><EFBFBD> R1<52><31>R1 <20><><EFBFBD>ڲ<EFBFBD><DAB2><EFBFBD><EFBFBD>ݽ<EFBFBD><DDBD>м<EFBFBD><D0BC>ܣ<EFBFBD>Ȼ<EFBFBD><C8BB><EFBFBD><EFBFBD><EFBFBD>¼<EFBFBD><C2BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݱ<EFBFBD><DDB1><EFBFBD><EFBFBD>ײ<EFBFBD><D7B2><EFBFBD>Դ<EFBFBD><D4B4>ַ<EFBFBD><D6B7>·<EFBFBD><C2B7><EFBFBD><EFBFBD> R1 <20><>ȫ<EFBFBD><C8AB><EFBFBD><EFBFBD>ַ 125.1.2.3<EFBFBD><EFBFBD>Ŀ<EFBFBD>ĵ<EFBFBD>ַ<EFBFBD><EFBFBD>·<EFBFBD><EFBFBD><EFBFBD><EFBFBD> R2 <20><>ȫ<EFBFBD><C8AB><EFBFBD><EFBFBD>ַ 194.4.5.6<EFBFBD><EFBFBD>·<EFBFBD><EFBFBD><EFBFBD><EFBFBD> R2 <20>յ<EFBFBD><D5B5><EFBFBD><EFBFBD>ݱ<EFBFBD><DDB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݲ<EFBFBD><DDB2>ֽ<EFBFBD><D6BD>н<EFBFBD><D0BD>ܣ<EFBFBD><DCA3>ָ<EFBFBD>ԭ<EFBFBD><D4AD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݱ<EFBFBD><DDB1><EFBFBD><EFBFBD><EFBFBD>ʱĿ<CAB1>ĵ<EFBFBD>ַΪ 10.2.0.3<EFBFBD><EFBFBD><EFBFBD>ͽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Y<><59>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/bf4ed077-d481-4db7-9e7a-85d841a5a8c3.jpg)

## <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ַת<D6B7><D7AA> NAT

ר<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڲ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʹ<EFBFBD>ñ<EFBFBD><EFBFBD><EFBFBD> IP <20><>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD><EFBFBD>ͻ<EFBFBD><CDBB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϵ<EFBFBD><CFB5><EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD><CDA8>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʹ<EFBFBD><CAB9> NAT <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> IP ת<><D7AA>Ϊȫ<CEAA><C8AB> IP<49><50>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǰ<EFBFBD><EFBFBD>NAT <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> IP <20><>ȫ<EFBFBD><C8AB> IP һһ<D2BB><D2BB>Ӧ<EFBFBD><D3A6><EFBFBD><EFBFBD><EFBFBD>ַ<EFBFBD>ʽ<EFBFBD><CABD>ӵ<EFBFBD><D3B5> n <20><>ȫ<EFBFBD><C8AB> IP <20><>ַ<EFBFBD><D6B7>ר<EFBFBD><D7A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֻ<EFBFBD><D6BB><EFBFBD><EFBFBD>ͬʱ<CDAC><CAB1> n ̨<><CCA8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>뻥<EFBFBD><EBBBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD>˸<EFBFBD><CBB8><EFBFBD>Ч<EFBFBD><D0A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȫ<EFBFBD><C8AB> IP <20><>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD><EFBFBD>ڳ<EFBFBD><DAB3>õ<EFBFBD> NAT ת<><D7AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ķ˿ں<CBBF>Ҳ<EFBFBD><D2B2><EFBFBD><EFBFBD><EFBFBD>ˣ<EFBFBD><CBA3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʹ<EFBFBD>ö<EFBFBD><C3B6><EFBFBD>ר<EFBFBD><D7A8><EFBFBD><EFBFBD><EFBFBD>ڲ<EFBFBD><DAB2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB>ȫ<EFBFBD><C8AB> IP <20><>ַ<EFBFBD><D6B7>ʹ<EFBFBD>ö˿ںŵ<DABA> NAT Ҳ<><D2B2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ַ<EFBFBD><D6B7><EFBFBD>˿<EFBFBD>ת<EFBFBD><D7AA> NAPT<50><54>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/0f31bc7a-d60b-48a6-8e3f-597708369e52.png)

# <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>*

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֻ<EFBFBD>ѷ<EFBFBD><EFBFBD>鷢<EFBFBD>͵<EFBFBD>Ŀ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD>ŵIJ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>еĽ<EFBFBD><EFBFBD>̡<EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ṩ<EFBFBD><EFBFBD>Ӧ<EFBFBD>ý<EFBFBD><EFBFBD>̼<EFBFBD><EFBFBD><EFBFBD><EFBFBD>߼<EFBFBD>ͨ<EFBFBD>š<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>߲<EFBFBD><EFBFBD>û<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ĺ<EFBFBD><EFBFBD><EFBFBD>ϸ<EFBFBD>ڣ<EFBFBD>ʹӦ<EFBFBD>ó<EFBFBD><EFBFBD>򿴼<EFBFBD><EFBFBD>ĺ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʵ<EFBFBD><EFBFBD>֮<EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD>˵<EFBFBD><EFBFBD>˵<EFBFBD><EFBFBD>߼<EFBFBD>ͨ<EFBFBD><EFBFBD><EFBFBD>ŵ<EFBFBD><EFBFBD><EFBFBD>

## UDP <20><> TCP <20><><EFBFBD>ص<EFBFBD>

<EFBFBD>û<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݰ<EFBFBD>Э<EFBFBD><EFBFBD> UDP<44><50>User Datagram Protocol<6F><6C>
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Э<EFBFBD><EFBFBD> TCP<43><50>Transmission Control Protocol<6F><6C>

UDP <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӵģ<D3B5><C4A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ܽ<EFBFBD><DCBD><EFBFBD><EFBFBD><EFBFBD>û<EFBFBD><C3BB>ӵ<EFBFBD><D3B5><EFBFBD><EFBFBD><EFBFBD>ƣ<EFBFBD><C6A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ģ<EFBFBD><C4A3><EFBFBD><EFBFBD><EFBFBD>Ӧ<EFBFBD>ó<EFBFBD><C3B3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ı<EFBFBD><C4B1>IJ<EFBFBD><C4B2>ϲ<EFBFBD>Ҳ<EFBFBD><D2B2><EFBFBD><EFBFBD><EFBFBD>֣<EFBFBD>ֻ<EFBFBD><D6BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD> UDP <20>ײ<EFBFBD><D7B2><EFBFBD><EFBFBD><EFBFBD>

TCP <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӵģ<D3B5><C4A3>ṩ<EFBFBD>ɿ<EFBFBD><C9BF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ƣ<EFBFBD>ӵ<EFBFBD><D3B5><EFBFBD><EFBFBD><EFBFBD>ƣ<EFBFBD><C6A3>ṩȫ˫<C8AB><CBAB>ͨ<EFBFBD>ţ<EFBFBD><C5A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֽ<EFBFBD><D6BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ӧ<EFBFBD>ò㴫<C3B2><E3B4AB><EFBFBD><EFBFBD><EFBFBD>ı<EFBFBD><C4B1>Ŀ<EFBFBD><C4BF><EFBFBD><EFBFBD>ֽ<EFBFBD><D6BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֽ<EFBFBD><D6BD><EFBFBD><EFBFBD><EFBFBD>֯<EFBFBD>ɴ<EFBFBD>С<EFBFBD><D0A1><EFBFBD>ȵ<EFBFBD><C8B5><EFBFBD><EFBFBD>ݿ飩

## UDP <20>ײ<EFBFBD><D7B2><EFBFBD>ʽ

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/bd6c05f3-02ee-4c8a-b374-40c87154a898.jpg)

<EFBFBD>ײ<EFBFBD><EFBFBD>ֶ<EFBFBD>ֻ<EFBFBD><EFBFBD> 8 <20><><EFBFBD>ֽڣ<D6BD><DAA3><EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD>˿ڡ<CBBF>Ŀ<EFBFBD>Ķ˿ڡ<CBBF><DAA1><EFBFBD><EFBFBD>ȡ<EFBFBD><C8A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>͡<EFBFBD>12 <20>ֽڵ<D6BD>α<EFBFBD>ײ<EFBFBD><D7B2><EFBFBD>Ϊ<EFBFBD>˼<EFBFBD><CBBC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ͷ<EFBFBD><CDB6><EFBFBD>ʱ<EFBFBD><CAB1><EFBFBD>ӵġ<D3B5>

## TCP <20>ײ<EFBFBD><D7B2><EFBFBD>ʽ

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/21a00b02-c0a6-4bcd-9af0-5ec6bb66e34c.jpg)

**<2A><><EFBFBD><EFBFBD>** <20><><EFBFBD><EFBFBD><EFBFBD>ڶ<EFBFBD><DAB6>ֽ<EFBFBD><D6BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>б<EFBFBD><D0B1>ţ<EFBFBD><C5A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ 301<30><31><EFBFBD><EFBFBD>ʾ<EFBFBD><CABE>һ<EFBFBD><D2BB><EFBFBD>ֽڵı<DAB5><C4B1><EFBFBD>Ϊ 301<30><31><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Я<EFBFBD><D0AF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݳ<EFBFBD><DDB3><EFBFBD>Ϊ 100 <20>ֽڣ<D6BD><DAA3><EFBFBD>ô<EFBFBD><C3B4>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD>Ķε<C4B6><CEB5><EFBFBD><EFBFBD><EFBFBD>ӦΪ 401<30><31>

**ȷ<>Ϻ<EFBFBD>** <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>յ<EFBFBD><D5B5><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD>Ķε<C4B6><CEB5><EFBFBD><EFBFBD>š<EFBFBD><C5A1><EFBFBD><EFBFBD><EFBFBD> B <20><>ȷ<EFBFBD>յ<EFBFBD> A <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD>ĶΣ<C4B6><CEA3><EFBFBD><EFBFBD><EFBFBD>Ϊ 501<30><31>Я<EFBFBD><D0AF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݳ<EFBFBD><DDB3><EFBFBD>Ϊ 200 <20>ֽڣ<D6BD><DAA3><EFBFBD><EFBFBD><EFBFBD> B <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD>Ķε<C4B6><CEB5><EFBFBD><EFBFBD><EFBFBD>Ϊ 701<30><31>B <20><><EFBFBD>͸<EFBFBD> A <20><>ȷ<EFBFBD>ϱ<EFBFBD><CFB1>Ķ<EFBFBD><C4B6><EFBFBD>ȷ<EFBFBD>Ϻž<CFBA>Ϊ 701<30><31>

**<2A><><EFBFBD><EFBFBD>ƫ<EFBFBD><C6AB>** <20><>ָ<EFBFBD><D6B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݲ<EFBFBD><DDB2>־<EFBFBD><D6BE>뱨<EFBFBD>Ķ<EFBFBD><C4B6><EFBFBD>ʼ<EFBFBD><CABC><EFBFBD><EFBFBD>ƫ<EFBFBD><C6AB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʵ<EFBFBD><CAB5><EFBFBD><EFBFBD>ָ<EFBFBD><D6B8><EFBFBD><EFBFBD><EFBFBD>ײ<EFBFBD><D7B2>ij<EFBFBD><C4B3>ȡ<EFBFBD>

**ȷ<><C8B7> ACK** <20><><EFBFBD><EFBFBD> ACK=1 ʱȷ<CAB1>Ϻ<EFBFBD><CFBA>ֶ<EFBFBD><D6B6><EFBFBD>Ч<EFBFBD><D0A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ч<EFBFBD><D0A7>TCP <20>涨<EFBFBD><E6B6A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӽ<EFBFBD><D3BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>д<EFBFBD><D0B4>͵ı<CDB5><C4B1>Ķζ<C4B6><CEB6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> ACK <20><> 1<><31>

**ͬ<><CDAC> SYN** <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӽ<EFBFBD><D3BD><EFBFBD>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD>ͬ<EFBFBD><CDAC><EFBFBD><EFBFBD><EFBFBD>š<EFBFBD><C5A1><EFBFBD> SYN=1<><31>ACK=0 ʱ<><CAB1>ʾ<EFBFBD><CABE><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ĶΡ<C4B6><CEA1><EFBFBD><EFBFBD>Է<EFBFBD>ͬ<EFBFBD>⽨<EFBFBD><E2BDA8><EFBFBD><EFBFBD><EFBFBD>ӣ<EFBFBD><D3A3><EFBFBD><EFBFBD><EFBFBD>Ӧ<EFBFBD><D3A6><EFBFBD><EFBFBD><EFBFBD><EFBFBD> SYN=1<><31>ACK=1<><31>

**<2A><>ֹ FIN** <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͷ<EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD>ӣ<EFBFBD><D3A3><EFBFBD> FIN=1 ʱ<><CAB1><EFBFBD><EFBFBD>ʾ<EFBFBD>˱<EFBFBD><CBB1>Ķεķ<CEB5><C4B7>ͷ<EFBFBD><CDB7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ѷ<EFBFBD><D1B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϣ<EFBFBD><CFA3><EFBFBD>Ҫ<EFBFBD><D2AA><EFBFBD>ͷ<EFBFBD><CDB7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӡ<EFBFBD>

**<2A><><EFBFBD><EFBFBD>** <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֵ<EFBFBD><D6B5>Ϊ<EFBFBD><CEAA><EFBFBD>շ<EFBFBD><D5B7>÷<EFBFBD><C3B7>ͷ<EFBFBD><CDB7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>䷢<EFBFBD>ʹ<EFBFBD><CDB4>ڵ<EFBFBD><DAB5><EFBFBD><EFBFBD>ݡ<EFBFBD>֮<EFBFBD><D6AE><EFBFBD><EFBFBD>Ҫ<EFBFBD><D2AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ƣ<EFBFBD><C6A3><EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD><CEAA><EFBFBD>շ<EFBFBD><D5B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݻ<EFBFBD><DDBB><EFBFBD><EFBFBD>ռ<EFBFBD><D5BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD>޵ġ<DEB5>

## TCP <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/086871db-5871-460f-97b7-126cd738bb0e.jpg)

<EFBFBD><EFBFBD><EFBFBD><EFBFBD> A Ϊ<>ͻ<EFBFBD><CDBB>ˣ<EFBFBD>B Ϊ<><CEAA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ˡ<EFBFBD>

1. <20><><EFBFBD><EFBFBD> B <20><><EFBFBD><EFBFBD> LISTEN<45><4E><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>״̬<D7B4><CCAC><EFBFBD>ȴ<EFBFBD><C8B4>ͻ<EFBFBD><CDBB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
2. A <20><> B <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ĶΣ<C4B6>SYN=1<><31>ACK=0<><30>ѡ<EFBFBD><D1A1>һ<EFBFBD><D2BB><EFBFBD><EFBFBD>ʼ<EFBFBD><CABC><EFBFBD><EFBFBD><EFBFBD><EFBFBD> x<><78>
3. B <20>յ<EFBFBD><D5B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ĶΣ<C4B6><CEA3><EFBFBD><EFBFBD><EFBFBD>ͬ<EFBFBD>⽨<EFBFBD><E2BDA8><EFBFBD><EFBFBD><EFBFBD>ӣ<EFBFBD><D3A3><EFBFBD><EFBFBD><EFBFBD> A <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȷ<EFBFBD>ϱ<EFBFBD><CFB1>ĶΣ<C4B6>SYN=1<><31>ACK=1<><31>ȷ<EFBFBD>Ϻ<EFBFBD>Ϊ x+1<><31>ͬʱҲѡ<D2B2><D1A1>һ<EFBFBD><D2BB><EFBFBD><EFBFBD>ʼ<EFBFBD><CABC><EFBFBD><EFBFBD><EFBFBD><EFBFBD> y<><79>
4. A <20>յ<EFBFBD> B <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȷ<EFBFBD>ϱ<EFBFBD><CFB1>Ķκ󣬻<CEBA>Ҫ<EFBFBD><D2AA> B <20><><EFBFBD><EFBFBD>ȷ<EFBFBD>ϣ<EFBFBD>ȷ<EFBFBD>Ϻ<EFBFBD>Ϊ y+1<><31><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ x+1<><31>
5. B <20>յ<EFBFBD> A <20><>ȷ<EFBFBD>Ϻ<EFBFBD><CFBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӽ<EFBFBD><D3BD><EFBFBD><EFBFBD><EFBFBD>


## TCP <20><><EFBFBD>Ĵλ<C4B4><CEBB><EFBFBD>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/78f65456-666b-4044-b4ee-f7692dbbc0d3.jpg)

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ź<EFBFBD>ȷ<EFBFBD>Ϻţ<EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD><EFBFBD><EFBFBD>ź<EFBFBD>ȷ<EFBFBD>ϺŵĹ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ƚϼ򵥡<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> ACK<43><4B><EFBFBD><EFBFBD>Ϊ ACK <20><><EFBFBD><EFBFBD><EFBFBD>ӽ<EFBFBD><D3BD><EFBFBD>֮<EFBFBD><D6AE><EFBFBD><EFBFBD>Ϊ 1<><31>

1. A <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͷű<CDB7><C5B1>ĶΣ<C4B6>FIN=1<><31>
2. B <20>յ<EFBFBD>֮<EFBFBD>󷢳<EFBFBD>ȷ<EFBFBD>ϣ<EFBFBD><CFA3><EFBFBD>ʱ TCP <20><><EFBFBD>ڰ<EFBFBD><DAB0>ر<EFBFBD>״̬<D7B4><CCAC>B <20><><EFBFBD><EFBFBD> A <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݵ<EFBFBD><DDB5><EFBFBD> A <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> B <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݣ<EFBFBD>
3. <20><> B Ҫ<><D2AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><D2AA><EFBFBD><EFBFBD>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͷ<EFBFBD><CDB7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ĶΣ<C4B6>FIN=1<><31>
4. A <20>յ<EFBFBD><D5B5>󷢳<EFBFBD>ȷ<EFBFBD>ϣ<EFBFBD><CFA3><EFBFBD>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD><EFBFBD>ͷš<CDB7>

**TIME_WAIT**

<EFBFBD>ͻ<EFBFBD><EFBFBD>˽<EFBFBD><EFBFBD>յ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>˵<EFBFBD> FIN <20><><EFBFBD>ĺ<EFBFBD><C4BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>״̬<D7B4><CCAC><EFBFBD><EFBFBD>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֱ<EFBFBD>ӽ<EFBFBD><D3BD><EFBFBD> CLOSED ״̬<D7B4><CCAC><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD>ȴ<EFBFBD>һ<EFBFBD><D2BB>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD><EFBFBD>õ<EFBFBD>ʱ<EFBFBD>䡣<EFBFBD><E4A1A3>ô<EFBFBD><C3B4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ɣ<EFBFBD>

1. ȷ<><C8B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB>ȷ<EFBFBD>ϱ<EFBFBD><CFB1>Ķ<EFBFBD><C4B6>ܹ<EFBFBD><DCB9><EFBFBD><EFBFBD><EFBFBD><EFA1A3><EFBFBD><EFBFBD> B û<>յ<EFBFBD> A <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȷ<EFBFBD>ϱ<EFBFBD><CFB1>ĶΣ<C4B6><CEA3><EFBFBD>ô<EFBFBD>ͻ<EFBFBD><CDBB><EFBFBD><EFBFBD>·<EFBFBD><C2B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͷ<EFBFBD><CDB7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ĶΣ<C4B6>A <20>ȴ<EFBFBD>һ<EFBFBD><D2BB>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD>˴<EFBFBD><CBB4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ķ<EFBFBD><C4B7><EFBFBD><EFBFBD><EFBFBD>
2. <20><><EFBFBD>ܴ<EFBFBD><DCB4>ڡ<EFBFBD><DAA1><EFBFBD>ʧЧ<CAA7><D0A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ĶΡ<C4B6><CEA1><EFBFBD>Ϊ<EFBFBD>˷<EFBFBD>ֹ<EFBFBD><D6B9><EFBFBD>ֱ<EFBFBD><D6B1>Ķγ<C4B6><CEB3><EFBFBD><EFBFBD>ڱ<EFBFBD><DAB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>֮<EFBFBD>⣬<EFBFBD><E2A3AC>Ҫ<EFBFBD>ȴ<EFBFBD>һ<EFBFBD><D2BB>ʱ<EFBFBD>䡣

## TCP <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/223fc26e-2fd6-484c-bcb7-443cac134f15.jpg)

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǻ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD>֣<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͷ<EFBFBD><EFBFBD>ͽ<EFBFBD><EFBFBD>շ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>շ<EFBFBD>ͨ<EFBFBD><EFBFBD> TCP <20><><EFBFBD>Ķ<EFBFBD><C4B6>еĴ<D0B5><C4B4><EFBFBD><EFBFBD>ֶθ<D6B6><CEB8>߷<EFBFBD><DFB7>ͷ<EFBFBD><CDB7>Լ<EFBFBD><D4BC>Ĵ<EFBFBD><C4B4>ڴ<EFBFBD>С<EFBFBD><D0A1><EFBFBD><EFBFBD><EFBFBD>ͷ<EFBFBD><CDB7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֵ<EFBFBD><D6B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϣ<EFBFBD><CFA2><EFBFBD><EFBFBD><EFBFBD>Լ<EFBFBD><D4BC>Ĵ<EFBFBD><C4B4>ڴ<EFBFBD>С<EFBFBD><D0A1>

<EFBFBD><EFBFBD><EFBFBD>ʹ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڵ<EFBFBD><EFBFBD>ֽڶ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>մ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڵ<EFBFBD><EFBFBD>ֽڶ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ա<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʹ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>󲿵<EFBFBD><EFBFBD>ֽ<EFBFBD><EFBFBD>Ѿ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ͳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>յ<EFBFBD><EFBFBD><EFBFBD>ȷ<EFBFBD>ϣ<EFBFBD><EFBFBD><EFBFBD>ô<EFBFBD>ͽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʹ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>룬ֱ<EFBFBD><EFBFBD><EFBFBD>󲿵<EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD>ֽڲ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ѷ<EFBFBD><EFBFBD>Ͳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȷ<EFBFBD>ϵ<EFBFBD>״̬<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>մ<EFBFBD><EFBFBD>ڵĻ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ƣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>մ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֽ<EFBFBD><EFBFBD>Ѿ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȷ<EFBFBD>ϲ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>մ<EFBFBD><EFBFBD>ڡ<EFBFBD>

<EFBFBD><EFBFBD><EFBFBD>մ<EFBFBD><EFBFBD><EFBFBD>ֻ<EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>򵽴<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֽڽ<EFBFBD><EFBFBD><EFBFBD>ȷ<EFBFBD>ϣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>մ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ѿ<EFBFBD><EFBFBD>յ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֽ<EFBFBD>Ϊ {31, 32, 34, 35}<7D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> {31, 32} <20><><EFBFBD>򵽴<F2B5BDB4><EFA3AC> {34, 35} <20>Ͳ<EFBFBD><CDB2>ǣ<EFBFBD><C7A3><EFBFBD><EFBFBD><EFBFBD>ֻ<EFBFBD><D6BB><EFBFBD>ֽ<EFBFBD> 32 <20><><EFBFBD><EFBFBD>ȷ<EFBFBD>ϡ<EFBFBD><CFA1><EFBFBD><EFBFBD>ͷ<EFBFBD><CDB7>õ<EFBFBD>һ<EFBFBD><D2BB><EFBFBD>ֽڵ<D6BD>ȷ<EFBFBD><C8B7>֮<EFBFBD>󣬾<EFBFBD>֪<EFBFBD><D6AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֽ<EFBFBD>֮ǰ<D6AE><C7B0><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֽڶ<D6BD><DAB6>Ѿ<EFBFBD><D1BE><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ա<EFBFBD>

## TCP <20>ɿ<EFBFBD><C9BF><EFBFBD><EFBFBD><EFBFBD>

TCP ʹ<>ó<EFBFBD>ʱ<EFBFBD>ش<EFBFBD><D8B4><EFBFBD>ʵ<EFBFBD>ֿɿ<D6BF><C9BF><EFBFBD><EFBFBD>䣺<EFBFBD><E4A3BA><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD>Ѿ<EFBFBD><D1BE><EFBFBD><EFBFBD>͵ı<CDB5><C4B1>Ķ<EFBFBD><C4B6>ڳ<EFBFBD>ʱʱ<CAB1><CAB1><EFBFBD><EFBFBD>û<EFBFBD><C3BB><EFBFBD>յ<EFBFBD>ȷ<EFBFBD>ϣ<EFBFBD><CFA3><EFBFBD>ô<EFBFBD><C3B4><EFBFBD>ش<EFBFBD><D8B4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ĶΡ<C4B6>

һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ķδӷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ٵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>յ<EFBFBD>ȷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD> RTT<54><54><EFBFBD><EFBFBD>Ȩƽ<C8A8><C6BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><CAB1> RTTs <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>£<EFBFBD>

![](http://latex.codecogs.com/gif.latex?\\\\RTTs=(1-a)*(RTTs)+a*RTT)

<EFBFBD><EFBFBD>ʱʱ<EFBFBD><EFBFBD> RTO Ӧ<><D3A6><EFBFBD>Դ<EFBFBD><D4B4><EFBFBD> RRTs<54><73>TCP ʹ<>õij<C3B5>ʱʱ<CAB1><CAB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>£<EFBFBD>

![](http://latex.codecogs.com/gif.latex?\\\\RTO=RTTs+4*RTT_d)

<EFBFBD><EFBFBD><EFBFBD><EFBFBD> RTT<sub>d</sub> Ϊƫ<CEAA><EFBFBD><EEA3AC><EFBFBD><EFBFBD><EFBFBD>µ<EFBFBD> RRT <20><> RRTs <20>йء<D0B9>

## TCP <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD>˿<EFBFBD><EFBFBD>Ʒ<EFBFBD><EFBFBD>ͷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʣ<EFBFBD><EFBFBD><EFBFBD>֤<EFBFBD><EFBFBD><EFBFBD>շ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ü<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ա<EFBFBD>

<EFBFBD><EFBFBD><EFBFBD>շ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>͵<EFBFBD>ȷ<EFBFBD>ϱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>еĴ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֶο<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ʒ<EFBFBD><EFBFBD>ͷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڴ<EFBFBD>С<EFBFBD><EFBFBD><EFBFBD>Ӷ<EFBFBD>Ӱ<EFBFBD>췢<EFBFBD>ͷ<EFBFBD><EFBFBD>ķ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʡ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>罫<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֶ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ 0<><30><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͷ<EFBFBD><CDB7><EFBFBD><EFBFBD>ܷ<EFBFBD><DCB7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݡ<EFBFBD>

## TCP ӵ<><D3B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>齫<EFBFBD>ᶪʧ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD>ͷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ش<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ӷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӵ<EFBFBD><EFBFBD><EFBFBD>̶ȸ<EFBFBD><EFBFBD>ߡ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>˵<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӵ<EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD>Ӧ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ʒ<EFBFBD><EFBFBD>ͷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʡ<EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ƺ<EFBFBD><EFBFBD>񣬵<EFBFBD><EFBFBD>dz<EFBFBD><EFBFBD><EFBFBD><EFBFBD>㲻ͬ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD><EFBFBD><EFBFBD>ý<EFBFBD><EFBFBD>շ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ü<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ܣ<EFBFBD><EFBFBD><EFBFBD>ӵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD>˽<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӵ<EFBFBD><EFBFBD><EFBFBD>̶ȡ<EFBFBD>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/a69af9bb-b5ad-4896-862d-697e5ee4feb1.png)

TCP <20><>Ҫͨ<D2AA><CDA8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>㷨<EFBFBD><E3B7A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӵ<EFBFBD><D3B5><EFBFBD><EFBFBD><EFBFBD>ƣ<EFBFBD><C6A3><EFBFBD><EFBFBD><EFBFBD>ʼ<EFBFBD><CABC>ӵ<EFBFBD><D3B5><EFBFBD><EFBFBD><EFBFBD>⡢<EFBFBD><E2A1A2><EFBFBD>ش<EFBFBD><D8B4><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ָ<EFBFBD><D6B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͷ<EFBFBD><CDB7><EFBFBD>Ҫά<D2AA><CEAC><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӵ<EFBFBD><D3B5><EFBFBD><EFBFBD><EFBFBD>ڣ<EFBFBD>cwnd<6E><64><EFBFBD><EFBFBD>״̬<D7B4><CCAC><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ע<EFBFBD><D7A2>ӵ<EFBFBD><D3B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>뷢<EFBFBD>ͷ<EFBFBD><CDB7><EFBFBD><EFBFBD>ڵ<EFBFBD><DAB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӵ<EFBFBD><D3B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֻ<EFBFBD><D6BB>һ<EFBFBD><D2BB>״̬<D7B4><CCAC><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʵ<EFBFBD>ʾ<EFBFBD><CABE><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͷ<EFBFBD><CDB7>ܷ<EFBFBD><DCB7>Ͷ<EFBFBD><CDB6><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݵ<EFBFBD><DDB5>Ƿ<EFBFBD><C7B7>ͷ<EFBFBD><CDB7><EFBFBD><EFBFBD>ڡ<EFBFBD>

Ϊ<EFBFBD>˱<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ۣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>¼<EFBFBD><EFBFBD>裺

1. <20><><EFBFBD>շ<EFBFBD><D5B7><EFBFBD><EFBFBD>㹻<EFBFBD><E3B9BB><EFBFBD>Ľ<EFBFBD><C4BD>ջ<EFBFBD><D5BB>棬<EFBFBD><E6A3AC><EFBFBD>˲<EFBFBD><CBB2>ᷢ<EFBFBD><E1B7A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ƣ<EFBFBD>
2. <20><>Ȼ TCP <20>Ĵ<EFBFBD><C4B4>ڻ<EFBFBD><DABB><EFBFBD><EFBFBD>ֽڣ<D6BD><DAA3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>贰<EFBFBD>ڵĴ<DAB5>С<EFBFBD><D0A1>λΪ<CEBB><CEAA><EFBFBD>ĶΡ<C4B6>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/346244ff-98c1-4f12-9a87-d0832e8c04cf.jpg)

### <20><><EFBFBD><EFBFBD>ʼ<EFBFBD><CABC>ӵ<EFBFBD><D3B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD>͵<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ִ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʼ<EFBFBD><EFBFBD><EFBFBD><EFBFBD> cwnd=1<><31><EFBFBD><EFBFBD><EFBFBD>ͷ<EFBFBD>ֻ<EFBFBD>ܷ<EFBFBD><DCB7><EFBFBD> 1 <20><><EFBFBD><EFBFBD><EFBFBD>ĶΣ<C4B6><CEA3><EFBFBD><EFBFBD>յ<EFBFBD>ȷ<EFBFBD>Ϻ󣬽<CFBA> cwnd <20>ӱ<EFBFBD><D3B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>֮<EFBFBD><D6AE><EFBFBD><EFBFBD><EFBFBD>ͷ<EFBFBD><CDB7>ܹ<EFBFBD><DCB9><EFBFBD><EFBFBD>͵ı<CDB5><C4B1>Ķ<EFBFBD>Ϊ<EFBFBD><CEAA>2<EFBFBD><32>4<EFBFBD><34>8 ...

ע<EFBFBD>⵽<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʼÿ<EFBFBD><EFBFBD><EFBFBD>ִζ<EFBFBD><EFBFBD><EFBFBD> cwnd <20>ӱ<EFBFBD><D3B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> cwnd <20><><EFBFBD><EFBFBD><EFBFBD>ٶȷdz<C8B7><C7B3>죬<EFBFBD>Ӷ<EFBFBD>ʹ<EFBFBD>÷<EFBFBD><C3B7>ͷ<EFBFBD><CDB7><EFBFBD><EFBFBD>͵<EFBFBD><CDB5>ٶ<EFBFBD><D9B6><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ٶȹ<D9B6><C8B9>죬<EFBFBD><ECA3AC><EFBFBD><EFBFBD>ӵ<EFBFBD><D3B5><EFBFBD>Ŀ<EFBFBD><C4BF><EFBFBD>Ҳ<EFBFBD>͸<EFBFBD><CDB8>ߡ<EFBFBD><DFA1><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʼ<EFBFBD><CABC><EFBFBD><EFBFBD> ssthresh<73><68><EFBFBD><EFBFBD> cwnd >= ssthresh ʱ<><CAB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӵ<EFBFBD><D3B5><EFBFBD><EFBFBD><EFBFBD>⣬ÿ<E2A3AC><C3BF><EFBFBD>ִ<EFBFBD>ֻ<EFBFBD><D6BB> cwnd <20><> 1<><31>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>˳<EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> ssthresh = cwnd / 2<><32>Ȼ<EFBFBD><C8BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ִ<EFBFBD><D6B4><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʼ<EFBFBD><CABC>

### <20><><EFBFBD>ش<EFBFBD><D8B4><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ָ<EFBFBD>

<EFBFBD>ڽ<EFBFBD><EFBFBD>շ<EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD>ÿ<EFBFBD>ν<EFBFBD><EFBFBD>յ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ķζ<EFBFBD>Ӧ<EFBFBD>÷<EFBFBD><EFBFBD>Ͷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>յ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ķε<EFBFBD>ȷ<EFBFBD>ϣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ѿ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>յ<EFBFBD> M<sub>1</sub> <20><> M<sub>2</sub><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD>յ<EFBFBD> M<sub>4</sub><EFBFBD><EFBFBD>Ӧ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ͷ<EFBFBD> M<sub>2</sub> <20><>ȷ<EFBFBD>ϡ<EFBFBD>

<EFBFBD>ڷ<EFBFBD><EFBFBD>ͷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>յ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ظ<EFBFBD>ȷ<EFBFBD>ϣ<EFBFBD><EFBFBD><EFBFBD>ô<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ķζ<EFBFBD>ʧ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>յ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> M<sub>2</sub> <20><><EFBFBD><EFBFBD> M<sub>3</sub> <20><>ʧ<EFBFBD><CAA7><EFBFBD><EFBFBD>ʱִ<CAB1>п<EFBFBD><D0BF>ش<EFBFBD><D8B4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ش<EFBFBD><D8B4><EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD>ĶΡ<C4B6>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>£<EFBFBD>ֻ<EFBFBD>Ƕ<EFBFBD>ʧ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ĶΣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ִ<EFBFBD>п<EFBFBD><EFBFBD>ָ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> ssthresh = cwnd / 2 <20><>cwnd = ssthresh<73><68>ע<EFBFBD>⵽<EFBFBD><E2B5BD>ʱֱ<CAB1>ӽ<EFBFBD><D3BD><EFBFBD>ӵ<EFBFBD><D3B5><EFBFBD><EFBFBD><EFBFBD>⡣

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/b18d679b-c8e2-4564-88ee-7600090e46da.jpg)

# <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Ӧ<>ò<EFBFBD>*

## <20><><EFBFBD><EFBFBD>ϵͳ DNS

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ IP <20><>ַ<EFBFBD><D6B7>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ƴɷֲ<EFBFBD>ʽϵͳ<EFBFBD><EFBFBD>

### 1. <20><><EFBFBD>νṹ

һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ɶ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ι<EFBFBD><EFBFBD>ɣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϲ㵽<EFBFBD>²<EFBFBD><EFBFBD>ֱ<EFBFBD>Ϊ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Լ<EFBFBD><EFBFBD>ļ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ի<EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/c2117f61-1177-4768-bf33-cf4f950d911c.png)

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/a4b162e5-db2a-4a27-b213-1fe481c5a06a.png)

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Է<EFBFBD>Ϊ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ࣺ

**(1) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>**<2A><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

**(2) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>**<2A><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

**(3) Ȩ<><C8A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>**<2A><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڵ<EFBFBD><DAB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ĸ<EFBFBD><EFBFBD>ͬ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>л<EFBFBD><EFBFBD>ֶ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͼ b <20><><EFBFBD><EFBFBD> abc.com <20>л<EFBFBD><D0BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>abc.com <20><> y.abc.com

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/fc0c6b2d-68c7-4de8-aaaa-97355a4f0472.jpg)

<EFBFBD><EFBFBD><EFBFBD>˾<EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ȩ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/8b335d94-c1ca-42e1-ad48-bb179d28a4f1.jpg)

**(4) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>**<2A><>Ҳ<EFBFBD><D2B2>ΪĬ<CEAA><C4AC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ø<EFBFBD><C3B8>ٻ<EFBFBD><D9BB>档

### 2. <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>򱾵<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ĺ<EFBFBD><EFBFBD>̲<EFBFBD><EFBFBD>õݹ飬<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʹ<EFBFBD>õݹ<EFBFBD><EFBFBD>͵<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ַ<EFBFBD>ʽ<EFBFBD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ķ<EFBFBD>ʽ<EFBFBD>£<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>֮<EFBFBD>󣬽<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ص<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ȼ<EFBFBD>󱾵<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݹ<EFBFBD><EFBFBD>ط<EFBFBD>ʽ<EFBFBD>£<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֱ<EFBFBD>ӷ<EFBFBD><EFBFBD>صģ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ǽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǰ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ľ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ż᷵<EFBFBD>ء<EFBFBD>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/6bc61bb8-3b1c-4dc8-ac25-cef925ace0eb.jpg)

## <20>ļ<EFBFBD><C4BC><EFBFBD><EFBFBD><EFBFBD>Э<EFBFBD><D0AD> FTP

FTP <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʹ<EFBFBD><CAB9> TCP<43><50><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><D2AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>е<EFBFBD> TCP <20><><EFBFBD>ӣ<EFBFBD><D3A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ӻ<EFBFBD><D3BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӡ<EFBFBD><D3A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ự<EFBFBD>ڼ<EFBFBD>һֱ<D2BB><D6B1><EFBFBD>ִ򿪣<D6B4><F2BFAAA3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݴ<EFBFBD><DDB4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>֮<EFBFBD><D6AE><EFBFBD>͹رա<D8B1><D5A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʹ<EFBFBD>ö˿ں<CBBF> 21<32><31><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʹ<EFBFBD>ö˿ں<CBBF> 20<32><30>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/58633775-8584-4a01-ad3f-eee4d9a466e1.jpg)

## Զ<><D4B6><EFBFBD>ն<EFBFBD>Э<EFBFBD><D0AD> TELNET

TELNET <20><><EFBFBD>ڵ<EFBFBD>¼<EFBFBD><C2BC>Զ<EFBFBD><D4B6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϣ<EFBFBD><CFA3><EFBFBD><EFBFBD><EFBFBD>Զ<EFBFBD><D4B6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϵ<EFBFBD><CFB5><EFBFBD><EFBFBD><EFBFBD>Ҳ<EFBFBD>᷵<EFBFBD>ء<EFBFBD>

TELNET <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ӧ<EFBFBD><D3A6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ͳ<EFBFBD><CDB2><EFBFBD>ϵͳ<CFB5>IJ<EFBFBD><C4B2>죬<EFBFBD><ECA3AC><EFBFBD>粻ͬ<E7B2BB><CDAC><EFBFBD><EFBFBD>ϵͳϵͳ<CFB5>Ļ<EFBFBD><C4BB>з<EFBFBD><D0B7><EFBFBD><EFBFBD>塣

## <20><>ά<EFBFBD><CEAC> WWW

<EFBFBD><EFBFBD> HTTP <20>ʼǡ<CABC>

## <20><><EFBFBD><EFBFBD><EFBFBD>ʼ<EFBFBD>Э<EFBFBD><D0AD>

һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʼ<EFBFBD>ϵͳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ɣ<EFBFBD><EFBFBD>û<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʼ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Լ<EFBFBD><EFBFBD>ʼ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Э<EFBFBD><EFBFBD><EFBFBD>Ͷ<EFBFBD>ȡЭ<EFBFBD>顣<EFBFBD><EFBFBD><EFBFBD>з<EFBFBD><EFBFBD><EFBFBD>Э<EFBFBD>鳣<EFBFBD><EFBFBD> SMTP<54><50><EFBFBD><EFBFBD>ȡЭ<C8A1>鳣<EFBFBD><E9B3A3> POP3 <20><> IMAP<41><50>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/de1e46d2-748f-4da3-a29e-7de7bc840366.jpg)

### POP3

POP3 <20><><EFBFBD>ص<EFBFBD><D8B5><EFBFBD>ֻҪ<D6BB>û<EFBFBD><C3BB>ӷ<EFBFBD><D3B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>϶<EFBFBD>ȡ<EFBFBD><C8A1><EFBFBD>ʼ<EFBFBD><CABC><EFBFBD><EFBFBD>ͰѸ<CDB0><D1B8>ʼ<EFBFBD>ɾ<EFBFBD><C9BE><EFBFBD><EFBFBD>

### IMAP

IMAP Э<><D0AD><EFBFBD>пͻ<D0BF><CDBB>˺ͷ<CBBA><CDB7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϵ<EFBFBD><CFB5>ʼ<EFBFBD><CABC><EFBFBD><EFBFBD><EFBFBD>ͬ<EFBFBD><CDAC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȥ<EFBFBD>ֶ<EFBFBD>ɾ<EFBFBD><C9BE><EFBFBD>ʼ<EFBFBD><CABC><EFBFBD><EFBFBD><EFBFBD>ô<EFBFBD><C3B4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϵ<EFBFBD><CFB5>ʼ<EFBFBD>Ҳ<EFBFBD><D2B2><EFBFBD>ᱻɾ<E1B1BB><C9BE><EFBFBD><EFBFBD>IMAP <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>û<EFBFBD><C3BB><EFBFBD>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD>ȥ<EFBFBD><C8A5><EFBFBD>ʷ<EFBFBD><CAB7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϵ<EFBFBD><CFB5>ʼ<EFBFBD><CABC><EFBFBD>IMAP Э<><D0AD>Ҳ֧<D2B2>ִ<EFBFBD><D6B4><EFBFBD><EFBFBD>Զ<EFBFBD><D4B6><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ļ<EFBFBD><C4BC>С<EFBFBD>

### SMTP

SMTP ֻ<>ܷ<EFBFBD><DCB7><EFBFBD> ASCII <20>룬<EFBFBD><EBA3AC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʼ<EFBFBD><CABC><EFBFBD><EFBFBD><EFBFBD> MIME <20><><EFBFBD>Է<EFBFBD><D4B7>Ͷ<EFBFBD><CDB6><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ļ<EFBFBD><C4BC><EFBFBD>MIME <20><>û<EFBFBD>иĶ<D0B8><C4B6><EFBFBD><EFBFBD><EFBFBD>ȡ<EFBFBD><C8A1> SMTP<54><50><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʼ<EFBFBD><CABC><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ľṹ<C4BD><E1B9B9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>˷<EFBFBD> ASCII <20><><EFBFBD>ı<EFBFBD><C4B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/ed5522bb-3a60-481c-8654-43e7195a48fe.png)

## <20><>̬<EFBFBD><CCAC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Э<EFBFBD><D0AD> DHCP

DHCP <20>ṩ<EFBFBD>˼<EFBFBD><CBBC>弴<EFBFBD>õ<EFBFBD><C3B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʽ<EFBFBD><CABD><EFBFBD>û<EFBFBD><C3BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫȥ<D2AA>ֶ<EFBFBD><D6B6><EFBFBD><EFBFBD><EFBFBD> IP <20><>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD>Ϣ<EFBFBD><CFA2>

DHCP <20><><EFBFBD>õ<EFBFBD><C3B5><EFBFBD><EFBFBD>ݲ<EFBFBD><DDB2><EFBFBD><EFBFBD><EFBFBD> IP <20><>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>롢Ĭ<EBA1A2><C4AC>·<EFBFBD><C2B7><EFBFBD><EFBFBD> IP <20><>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> IP <20><>ַ<EFBFBD><D6B7>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʽ<EFBFBD><EFBFBD><EFBFBD>£<EFBFBD><EFBFBD><EFBFBD>Ҫ IP <20><>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>㲥<EFBFBD><E3B2A5><EFBFBD><EFBFBD> DHCP <20><><EFBFBD>ֱ<EFBFBD><D6B1>ģ<EFBFBD><C4A3><EFBFBD>Ŀ<EFBFBD>ĵ<EFBFBD>ַ<EFBFBD><D6B7>Ϊȫ 1<><31><EFBFBD><EFBFBD> 255.255.255.255:67<36><37>Դ<EFBFBD><D4B4>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD>Ϊȫ 0<><30><EFBFBD><EFBFBD> 0.0.0.0:68<36><38><EFBFBD><EFBFBD>DHCP <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>յ<EFBFBD><D5B5><EFBFBD><EFBFBD>ֱ<EFBFBD><D6B1><EFBFBD>֮<EFBFBD><D6AE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> IP <20><>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD>ȡһ<C8A1><D2BB><EFBFBD><EFBFBD>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD> DHCP <20>ṩ<EFBFBD><E1B9A9><EFBFBD>ĸ<EFBFBD><C4B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

## <20><><EFBFBD>Ե㴫<D4B5><E3B4AB> P2P

<EFBFBD><EFBFBD>ij<EFBFBD><EFBFBD><EFBFBD>ļ<EFBFBD><EFBFBD>ַ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>жԵȼ<EFBFBD><EFBFBD>ϳ<EFBFBD>Ϊһ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ļ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݵ<EFBFBD>Ԫ<EFBFBD><EFBFBD>Ϊ<EFBFBD>ļ<EFBFBD><EFBFBD>飬<EFBFBD><EFBFBD><EFBFBD>Ĵ<EFBFBD>С<EFBFBD>ǹ̶<EFBFBD><EFBFBD>ġ<EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD>µĶԵȷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ij<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD>ʼ<EFBFBD><EFBFBD>û<EFBFBD><EFBFBD><EFBFBD>ļ<EFBFBD><EFBFBD>飬<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ܹ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Եȷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>𽥵<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ص<EFBFBD>һЩ<EFBFBD>ļ<EFBFBD><EFBFBD>飬<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͬʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ҲΪ<EFBFBD><EFBFBD><EFBFBD>ĶԵȷ<EFBFBD><EFBFBD>ϴ<EFBFBD>һЩ<EFBFBD>ļ<EFBFBD><EFBFBD>顣

ÿ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʩ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ׷<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD>Եȷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>׷<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ǽǣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ե<EFBFBD>֪ͨ׷<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ں<EFBFBD><EFBFBD><EFBFBD><EFBFBD>С<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>κ<EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>˳<EFBFBD>ij<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

һ<EFBFBD><EFBFBD><EFBFBD>µĶԵȷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD>׷<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ӻ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ѡ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ɸ<EFBFBD><EFBFBD>Եȷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>¶Եȷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Щ<EFBFBD>Եȷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Щ<EFBFBD>Եȷ<EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD><EFBFBD><EFBFBD>ڶԵȷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>պͷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ļ<EFBFBD><EFBFBD>鶼<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڶԵȷ<EFBFBD><EFBFBD>н<EFBFBD><EFBFBD>С<EFBFBD>

<EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD>Եȷ<EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD>ܶ<EFBFBD><EFBFBD>ļ<EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD>ͨ<EFBFBD><EFBFBD>ʹ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϡ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȵIJ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȡ<EFBFBD><EFBFBD><EFBFBD>ļ<EFBFBD><EFBFBD>飬Ҳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD>ļ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڶԵȷ<EFBFBD><EFBFBD>и<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>٣<EFBFBD><EFBFBD><EFBFBD>ô<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ļ<EFBFBD><EFBFBD>顣

<EFBFBD><EFBFBD><EFBFBD>ܶ<EFBFBD><EFBFBD>Եȷ<EFBFBD><EFBFBD><EFBFBD>ͬһ<EFBFBD><EFBFBD><EFBFBD>Եȷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ļ<EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD>öԵȷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ѡ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>䷢<EFBFBD><EFBFBD><EFBFBD>ļ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ĶԵȷ<EFBFBD><EFBFBD><EFBFBD>

P2P <20><>һ<EFBFBD><D2BB><EFBFBD>ֲ<EFBFBD>ʽϵͳ<CFB5><CDB3><EFBFBD>κ<EFBFBD>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD><EFBFBD>жԵȷ<D4B5><C8B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>˳<EFBFBD><CBB3><EFBFBD>ʹ<EFBFBD>÷ֲ<C3B7>ʽɢ<CABD>б<EFBFBD> DHT<48><54><EFBFBD><EFBFBD><EFBFBD>Բ<EFBFBD><D4B2>Һ<EFBFBD><D2BA><EFBFBD><EFBFBD>е<EFBFBD><D0B5><EFBFBD>Դ<EFBFBD><D4B4> IP <20><>ַӳ<D6B7>䡣

## Web ҳ<><D2B3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

1.  <20><> DNS <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> DNS <20><>ѯ<EFBFBD><D1AF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

2. <20><>ʼ<EFBFBD><CABC><EFBFBD><EFBFBD> HTTP <20>Ự<EFBFBD><E1BBB0><EFBFBD><EFBFBD>Ҫ<EFBFBD>Ƚ<EFBFBD><C8BD><EFBFBD> TCP <20><><EFBFBD>ӡ<EFBFBD>

3. <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ĵ<EFBFBD><C4B4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>У<EFBFBD>HTTP <20><><EFBFBD>ı<EFBFBD><C4B1><EFBFBD>װ<EFBFBD><D7B0> TCP <20>С<EFBFBD>HTTP <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʹ<EFBFBD>ö˿ں<CBBF> 80<38><30><EFBFBD><EFBFBD>Ϊ<EFBFBD><CEAA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 80 <20>˿ڡ<CBBF><DAA1><EFBFBD><EFBFBD>ӽ<EFBFBD><D3BD><EFBFBD>֮<EFBFBD>󣬷<EFBFBD><F3A3ACB7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD>˿ںŸ<DABA><C5B8>ض<EFBFBD><D8B6>Ŀͻ<C4BF><CDBB>ˣ<EFBFBD>֮<EFBFBD><D6AE><EFBFBD><EFBFBD> TCP <20><><EFBFBD>䶼<EFBFBD><E4B6BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ķ˿ںš<DABA>

4. <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ĵ<EFBFBD><C4B4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>У<EFBFBD>TCP <20><><EFBFBD>Ķλᱻ<CEBB><E1B1BB>װ<EFBFBD><D7B0> IP <20><><EFBFBD><EFBFBD><EFBFBD>У<EFBFBD>IP <20><><EFBFBD>龭<EFBFBD><E9BEAD>·<EFBFBD><C2B7>ѡ<EFBFBD><D1A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>󵽴<EFBFBD>Ŀ<EFBFBD>ĵء<C4B5>

5. <20><><EFBFBD><EFBFBD>·<EFBFBD>㣬IP <20><><EFBFBD><EFBFBD><EFBFBD>ᱻ<EFBFBD><E1B1BB>װ<EFBFBD><D7B0> MAC ֡<>У<EFBFBD>IP <20><>ַ<EFBFBD><D6B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD> MAC <20><>ַ<EFBFBD><D6B7>Ҫʹ<D2AA><CAB9> ARP<52><50>

6. <20>ͻ<EFBFBD><CDBB>˷<EFBFBD><CBB7><EFBFBD> HTTP <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ģ<EFBFBD><C4A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȡҳ<C8A1>档

7. <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> HTTP <20><>Ӧ<EFBFBD><D3A6><EFBFBD>ģ<EFBFBD><C4A3>ͻ<EFBFBD><CDBB>˴Ӷ<CBB4><D3B6><EFBFBD>ȡ<EFBFBD><C8A1>ҳ<EFBFBD>档

8. <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>õ<EFBFBD>ҳ<EFBFBD><D2B3><EFBFBD><EFBFBD><EFBFBD><EFBFBD>֮<EFBFBD>󣬽<EFBFBD><F3A3ACBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ⱦ<EFBFBD><C8BE><EFBFBD><EFBFBD><EFBFBD>û<EFBFBD>չʾҳ<CABE>档


## <20><><EFBFBD>ö˿<C3B6>

| Ӧ<>ò<EFBFBD>Э<EFBFBD><D0AD> | <20>˿ں<CBBF> | <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Э<EFBFBD><D0AD> |
| -- | -- | -- |
| DNS | 53 | UDP |
| FTP | <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 21<32><31><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 20 | TCP |
| TELNET | 23 | TCP |
| DHCP | 67 68 | UDP |
| HTTP | 80 | TCP |
| SMTP | 25 | TCP |
| POP3 | 110 | TCP |
| IMAP | 143 | TCP |

# <20>ο<EFBFBD><CEBF><EFBFBD><EFBFBD><EFBFBD>

- <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD>߰<EFBFBD>
- <20>Զ<EFBFBD><D4B6><EFBFBD><EFBFBD>¼<EFBFBD><C2BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>