HC110110005ARP协议PPT精选文档

1、huawei technologies co., ltd.arp协议copyright 2014 huawei technologies co., ltd. all rights reserved. page 2前言网络设备有数据要发送给另一台网络设备时，必须要知道对方的网络层地址（即ip地址）。ip地址由网络层来提供，但是仅有ip地址是不够的，ip数据报文必须封装成帧才能通过数据链路进行发送。数据帧必须要包含目的mac地址，因此发送端还必须获取到目的mac地址。通过目的ip地址而获取目的mac地址的过程是由arp（address resolution protocol）协议来实现的。copy

2、right 2014 huawei technologies co., ltd. all rights reserved. page 3学习目标学完本课程后，您应该能：l掌握arp的工作原理l理解arp缓存表的作用copyright 2014 huawei technologies co., ltd. all rights reserved. page 4arpip: 10.1.1.1/24mac: 00-01-02-03-04-aa目的ip : 10.1.1.2源 ip: 10.1.1.1目的mac : 未知源mac : 00-01-02-03-04-aaip : 10.1.1.2/24ma

3、c: 00-01-02-03-04-bbeth_iiipdata fcs主机 a主机 bl数据链路层在进行数据封装时，需要目的mac地址。copyright 2014 huawei technologies co., ltd. all rights reserved. page 5arp数据包格式larp报文不能穿越路由器，不能被转发到其他广播域。fcsarphardware type hardware lengthprotocol typeprotocol lengthoperation codesource hardware addressdestination hardware addr

4、ess source protocol addressdestination protocol address03115ethernet_iicopyright 2014 huawei technologies co., ltd. all rights reserved. page 6arp工作过程主机 a10.0.0.2/2400-01-02-03-04-bb主机 c主机 b10.0.0.3/2400-01-02-03-04-cc10.0.0.1/2400-01-02-03-04-aal主机a发送一个数据包给主机c之前，首先要获取主机c的mac地址。copyright 2014 huawei

5、 technologies co., ltd. all rights reserved. page 7arp缓存host aarp -ainternet address physical address type主机 a10.0.0.2/2400-01-02-03-04-bb主机 c主机 b10.0.0.3/2400-01-02-03-04-cc10.0.0.1/2400-01-02-03-04-aacopyright 2014 huawei technologies co., ltd. all rights reserved. page 8arp请求主机 a10.0.0.2/2400-01-

6、02-03-04-bb主机 c主机 b10.0.0.3/2400-01-02-03-04-cc10.0.0.1/2400-01-02-03-04-aa源mac：00-01-02-03-04-aa 目的mac : ff-ff-ff-ff-ff-ffarp目的 ip: 10.0.0.3源 ip: 10.0.0.1目的 mac: 00-00-00-00-00-00 源 mac: 00-01-02-03-04-aa操作类型: requesteth_iifcscopyright 2014 huawei technologies co., ltd. all rights reserved. page 9a

7、rp响应主机 a10.0.0.2/2400-01-02-03-04-bb主机 c主机 b10.0.0.3/2400-01-02-03-04-cc10.0.0.1/2400-01-02-03-04-aahost carp -ainternet address physical address type 10.0.0.1 00-01-02-03-04-aa dynamiccopyright 2014 huawei technologies co., ltd. all rights reserved. page 10arp响应主机 a10.0.0.2/2400-01-02-03-04-bb主机 c主

8、机 b10.0.0.3/2400-01-02-03-04-cc10.0.0.1/2400-01-02-03-04-aa源mac：00-01-02-03-04-cc 目的ip : 10.0.0.1源 ip : 10.0.0.3目的 mac : 00-01-02-03-04-aa 源 mac : 00-01-02-03-04-cc操作类型: reply目的mac：00-01-02-03-04-aa arpeth_iifcscopyright 2014 huawei technologies co., ltd. all rights reserved. page 11arp缓存host aarp -

9、ainternet address physical address type 10.0.0.3 00-01-02-03-04-cc dynamic主机 a10.0.0.2/2400-01-02-03-04-bb主机 c主机 b10.0.0.3/2400-01-02-03-04-cc10.0.0.1/2400-01-02-03-04-aacopyright 2014 huawei technologies co., ltd. all rights reserved. page 12arp代理l位于不同网络的网络设备在不配置网关的情况下，能够通过arp代理实现相互通信。主机 a主机 b10.1.

10、0.1/820.2.0.1/8arp代理g0/0/0g0/0/120.2.0.2/810.1.0.2/8路由器发送arp reply发送arp request 请求20.2.0.1的mac地址copyright 2014 huawei technologies co., ltd. all rights reserved. page 13免费arp主机 aip: 10.0.0.1/24mac: 00-01-02-03-04-aa目的ip : 10.0.0.1源 ip : 10.0.0.1目的mac : 00-00-00-00-00-00源 mac : 00-01-02-03-04-aa源mac：00-01-02-03-04-aa 目的mac：ff-ff-ff-ff-