泪水多余 2007-12-3 20:00
生平第一篇技术文档－－－ping命令
[b][size=12pt][font=Times New Roman]1[/font][/size][/b][b][font=宋体][size=12pt]．什么是[/size][/font][/b][b][size=12pt][font=Times New Roman]ping[/font][/size][/b][b][font=宋体][size=12pt]？[/size][/font][/b][b][size=12pt][/size][/b]
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[size=12pt][font=Times New Roman]Ping[/font][/size][font=宋体][size=12pt]是[/size][/font][size=12pt][font=Times New Roman]Packet Internet Groper[/font][/size][font=宋体][size=12pt]的英文缩写。它使用[/size][/font][size=12pt][font=Times New Roman]ICMP[/font][/size][font=宋体][size=12pt]的[/size][/font][size=12pt][font=Times New Roman]echo[/font][/size][font=宋体][size=12pt]协议信息在互联网络上检查计算机间物理连接的连通性。[/size][/font][size=12pt][/size]
[table][tr][td=1,1,568][font=宋体][size=12pt]扩展：[/size][/font][size=12pt][font=Times New Roman]ICMP[/font][/size][font=宋体][size=12pt]（因特网控制报文协议），工作在网络层。被[/size][/font][size=12pt][font=Times New Roman]IP[/font][/size][font=宋体][size=12pt]用于提供控制和信息传递功能，是一个管理性协议。它的信息是被作为[/size][/font][size=12pt][font=Times New Roman]IP[/font][/size][font=宋体][size=12pt]数据报来传送的。[/size][/font][size=12pt][/size]
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echo[/font][/size][font=宋体][size=12pt]协议的结果可以有助于评估以下内容：[/size][/font][size=12pt][/size]
[size=12pt][font=Times New Roman]*[/font][/size][font=宋体][size=12pt]主机路径的可靠性[/size][/font][size=12pt][/size]
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*[/font][/size][font=宋体][size=12pt]路径的延迟[/size][/font][size=12pt][/size]
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*[/font][/size][font=宋体][size=12pt]主机能否到达或是否正在运行[/size][/font][size=12pt][/size]
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[size=12pt][font=Times New Roman]Ping[/font][/size][font=宋体][size=12pt]的操作可以在用户或特权[/size][/font][size=12pt][font=Times New Roman]EXEC[/font][/size][font=宋体][size=12pt]模式下执行。[/size][/font][size=12pt][/size]
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[size=12pt][font=Times New Roman]Ping[/font][/size][font=宋体][size=12pt]返回代码[/size][/font][size=12pt][/size]
[align=center][table][tr][td=1,1,55][align=center][font=宋体][size=12pt]代码[/size][/font][size=12pt][/size][/align]
[/td][td=1,1,324][align=center][font=宋体][size=12pt]含义[/size][/font][size=12pt][/size][/align]
[/td][/tr][tr][td=1,1,55][align=center][font=宋体][size=12pt]！[/size][/font][size=12pt][/size][/align]
[/td][td=1,1,324][align=center][font=宋体][size=12pt]收到一个[/size][/font][size=12pt][font=Times New Roman]ICMP[/font][/size][font=宋体][size=12pt]回应应答[/size][/font][size=12pt][/size][/align]
[/td][/tr][tr][td=1,1,55][align=center][b][size=12pt][font=Times New Roman].[/font][/size][/b][/align]
[/td][td=1,1,324][align=center][font=宋体][size=12pt]等待应答时网络服务超时[/size][/font][size=12pt][/size][/align]
[/td][/tr][tr][td=1,1,55][align=center][size=12pt][font=Times New Roman]U[/font][/size][/align]
[/td][td=1,1,324][align=center][font=宋体][size=12pt]收到一条[/size][/font][size=12pt][font=Times New Roman]ICMP[/font][/size][font=宋体][size=12pt]不可达信息[/size][/font][size=12pt][/size][/align]
[/td][/tr][tr][td=1,1,55][align=center][size=12pt][font=Times New Roman]C[/font][/size][/align]
[/td][td=1,1,324][align=center][font=宋体][size=12pt]收到一条[/size][/font][size=12pt][font=Times New Roman]ICMP[/font][/size][font=宋体][size=12pt]源抑制信息[/size][/font][size=12pt][/size][/align]
[/td][/tr][tr][td=1,1,55][align=center][size=12pt][font=Times New Roman]&[/font][/size][/align]
[/td][td=1,1,324][align=center][font=宋体][size=12pt]收到一条[/size][/font][size=12pt][font=Times New Roman]ICMP[/font][/size][font=宋体][size=12pt]超时信息[/size][/font][size=12pt][/size][/align]
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[b][size=12pt][font=Times New Roman]2[/font][/size][/b][b][font=宋体][size=12pt]．[/size][/font][/b][b][size=12pt][font=Times New Roman]Ping[/font][/size][/b][b][font=宋体][size=12pt]的工作流程[/size][/font][/b][b][size=12pt][/size][/b]
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[size=12pt][font=Times New Roman] [/font][/size][font=宋体][size=12pt]首先说明的是，[/size][/font][size=12pt][font=Times New Roman]ping[/font][/size][font=宋体][size=12pt]是一个双向过程，下面这个流程图只是将其中的一个方向大致的画了出来。在这个过程中还有数据的封装和解封装过程没有在图上表示。[/size][/font][size=12pt][/size]
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[size=12pt][font=Times New Roman] [/font][/size][font=宋体][size=12pt]由于[/size][/font][size=12pt][font=Times New Roman]ping[/font][/size][font=宋体][size=12pt]是一个双向过程，所以在[/size][/font][size=12pt][font=Times New Roman]ping[/font][/size][font=宋体][size=12pt] 失败的时候，许多人会认为数据包没有到达目的主机。但是，有时候也会是由于路由器等设备缺乏返回源方主机网络的路由并将数据包丢 弃！数据包被丢弃在返回源方的旅途中，并不是丢弃在它前往目的主机的过程中。 [/size][/font][size=12pt][/size]
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[size=12pt][font=Times New Roman] [/font][/size][font=宋体][size=12pt]还有一个需要注意的是。当主机[/size][/font][size=12pt][font=Times New Roman]A[/font][/size][font=宋体][size=12pt]发送数据包到不同网络的主机[/size][/font][size=12pt][font=Times New Roman]B[/font][/size][font=宋体][size=12pt] 时，所使用的目的方硬件地址时默认网关的以太网接口。这里因为数据帧是不可以被直接发送到远方网络的，它只有先发送到本地网络上 ，而且去往远程网络的数据包必须要通过默认网关转发[/size][/font][size=12pt][font=Times New Roman]![/font][/size]
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[size=3][size=10.5pt][font=Times New Roman]Ping[/font][/size][font=宋体][size=10.5pt]工作流程图[/size][/font][/size]
[size=3][font=宋体][size=10.5pt][img]http://www.one-tom.com/bbs/uploads/gairuhe/2006-11-03_164636_ping.jpg[/img][/size][/font][/size]
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[size=3][font=宋体][size=10.5pt][b][size=12pt][font=Times New Roman]3[/font][/size][/b][b][font=宋体][size=12pt]．实例分析[/size][/font][/b][b][size=12pt][/size][/b]
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TOPO1[/size][/font][font=宋体][size=12pt]：[/size][/font][size=12pt][/size]
[img]http://www.one-tom.com/bbs/uploads/gairuhe/2006-11-03_164713_topo1.jpg[/img]
[font=宋体][size=9pt]实验目的：了解当[/size][/font][size=9pt][font=Times New Roman]ping[/font][/size][font=宋体][size=9pt]自身的[/size][/font][size=9pt][font=Times New Roman]ip[/font][/size][font=宋体][size=9pt]地址时，[/size][/font][size=9pt][font=Times New Roman]ping[/font][/size][font=宋体][size=9pt]包是如何发送和接受的[/size][/font][size=9pt][/size]
[font=宋体][size=9pt]实验假想：既然是[/size][/font][size=9pt][font=Times New Roman]ping[/font][/size][font=宋体][size=9pt]自己那只要在自身内部发包和收包即可，不需要通过别的终端。[/size][/font][size=9pt][/size]
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[size=9pt][font=Times New Roman]RA[/font][/size][font=宋体][size=9pt]的配置：[/size][/font][size=9pt][/size]
[size=9pt][font=Times New Roman]Router>en[/font][/size]
[size=9pt][font=Times New Roman]Router#conf t[/font][/size]
[size=9pt][font=Times New Roman]Router(config)#host RA[/font][/size]
[size=9pt][font=Times New Roman]RA(config)#int s1/0[/font][/size]
[size=9pt][font=Times New Roman]RA(config-if)#ip add 192.168.1.2 255.255.255.0[/font][/size]
[size=9pt][font=Times New Roman]RA(config-if)#no shu[/font][/size]
[size=9pt][font=Times New Roman]RA(config-if)#clock rate 64000[/font][/size]
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[size=9pt][font=Times New Roman]RB[/font][/size][font=宋体][size=9pt]的配置：[/size][/font][size=9pt][/size]
[size=9pt][font=Times New Roman]Router>en[/font][/size]
[size=9pt][font=Times New Roman]Router#conf t[/font][/size]
[size=9pt][font=Times New Roman]Router(config)#host RB[/font][/size]
[size=9pt][font=Times New Roman]RB(config)#int s1/0[/font][/size]
[size=9pt][font=Times New Roman]RB(config-if)#ip add 192.168.1.1 255.255.255.0[/font][/size]
[size=9pt][font=Times New Roman]RB(config-if)#no shu[/font][/size]
[size=9pt][font=Times New Roman]RB(config-if)#end[/font][/size]
[size=9pt][font=Times New Roman]RB#debug ip pack[/font][/size]
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[size=9pt][font=Times New Roman]RB#ping 192.168.1.2[/font][/size]
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[size=9pt][font=Times New Roman]Type escape sequence to abort.[/font][/size]
[size=9pt][font=Times New Roman]Sending 5, 100-byte ICMP Echos to 192.168.1.2, timeout is 2 seconds:[/font][/size]
[size=9pt][font=Times New Roman]!!!!![/font][/size]
[size=9pt][font=Times New Roman]Success rate is 100 percent (5/5), round-trip min/avg/max =[b] [color=red]48/99/188 ms[/color][/b][/font][/size]
[size=9pt][font=Times New Roman]RB#[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:15.519: IP: tableid=0, s=192.168.1.1 (local), d=192.168.1.2 (Serial1/0), routed via FIB[/font][/size]
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3 12:59:15.523: IP: s=192.168.1.1 (local), d=192.168.1.2 (Serial1/0), len 100, sending[/font][/size]
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3 12:59:15.703: IP: tableid=0, s=192.168.1.2 (Serial1/0), d=192.168.1.1 (Serial1/0), routed via RIB[/font][/size]
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3 12:59:15.703: IP: s=192.168.1.2 (Serial1/0), d=192.168.1.1 (Serial1/0), len 100, rcvd 3[/font][/size]
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3 12:59:15.707: IP: tableid=0, s=192.168.1.1 (local), d=192.168.1.2 (Serial1/0), routed via FIB[/font][/size]
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3 12:59:15.711: IP: s=192.168.1.1 (local), d=192.168.1.2 (Serial1/0), len 100, sending[/font][/size]
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3 12:59:15.823: IP: tableid=0, s=192.168.1.2 (Serial1/0), d=192.168.1.1 (Serial1/0), routed via RIB[/font][/size]
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3 12:59:15.827: IP: s=192.168.1.2 (Serial1/0), d=192.168.1.1 (Serial1/0), len 100, rcvd 3[/font][/size]
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3 12:59:15.831: IP: tableid=0, s=192.168.1.1 (local), d=192.168.1.2 (Serial1/0), routed via FIB[/font][/size]
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3 12:59:15.831: IP: s=192.168.1.1 (local), d=192.168.1.2 (Serial1/0), len 100, sending[/font][/size]
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3 12:59:15.919: IP: tableid=0, s=192.168.1.2 (Serial1/0), d=192.168.1.1 (Serial1/0), routed via RIB[/font][/size]
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3 12:59:15.919: IP: s=192.168.1.2 (Serial1/0), d=192.168.1.1 (Serial1/0), len 100, rcvd 3[/font][/size]
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3 12:59:15.923: IP: tableid=0, s=192.168.1.1 (local), d=192.168.1.2 (Serial1/0), routed via FIB[/font][/size]
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3 12:59:15.927: IP: s=192.168.1.1 (local), d=192.168.1.2 (Serial1/0), len 100, sending[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:15.967: IP: tableid=0, s=192.168.1.2 (Serial1/0), d=192.168.1.1 (Serial1/0), routed via RIB[/font][/size]
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3 12:59:15.967: IP: s=192.168.1.2 (Serial1/0), d=192.168.1.1 (Serial1/0), len 100, rcvd 3[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:15.971: IP: tableid=0, s=192.168.1.1 (local), d=192.168.1.2 (Serial1/0), routed via FIB[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:15.975: IP: s=192.168.1.1 (local), d=192.168.1.2 (Serial1/0), len 100, sending[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:16.015: IP: tableid=0, s=192.168.1.2 (Serial1/0), d=192.168.1.1 (Serial1/0), routed via RIB[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:16.015: IP: s=192.168.1.2 (Serial1/0), d=192.168.1.1 (Serial1/0), len 100, rcvd 3[/font][/size]
[size=9pt][font=Times New Roman]RB#ping 192.168.1.1[/font][/size]
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[size=9pt][font=Times New Roman]Type escape sequence to abort.[/font][/size]
[size=9pt][font=Times New Roman]Sending 5, 100-byte ICMP Echos to 192.168.1.1, timeout is 2 seconds:[/font][/size]
[size=9pt][font=Times New Roman]!!!!![/font][/size]
[size=9pt][font=Times New Roman]Success rate is 100 percent (5/5), round-trip min/avg/max = [b][color=red]96/200/360 ms[/color][/b][/font][/size]
[size=9pt][font=Times New Roman]RB#[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:20.991: IP: tableid=0, s=192.168.1.1 (local), d=192.168.1.1 (Serial1/0), routed via RIB[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:20.995: IP: s=192.168.1.1 (local), d=192.168.1.1 (Serial1/0), len 100, sending[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:21.127: IP: tableid=0, s=192.168.1.2 (Serial1/0), d=192.168.1.1 (Serial1/0), routed via RIB[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:21.127: IP: s=192.168.1.2 (Serial1/0), d=192.168.1.1 (Serial1/0), len 56, rcvd 3[/font][/size]
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3 12:59:21.199: IP: tableid=0, s=192.168.1.1 (Serial1/0), d=192.168.1.1 (Serial1/0), routed via RIB[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:21.199: IP: s=192.168.1.1 (Serial1/0), d=192.168.1.1 (Serial1/0), len 100, rcvd 3[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:21.203: IP: tableid=0, s=192.168.1.1 (local), d=192.168.1.1 (Serial1/0), routed via RIB[/font][/size]
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3 12:59:21.207: IP: s=192.168.1.1 (local), d=192.168.1.1 (Serial1/0), len 100, sending[/font][/size]
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3 12:59:21.271: IP: tableid=0, s=192.168.1.1 (Serial1/0), d=192.168.1.1 (Serial1/0), routed via RIB[/font][/size]
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3 12:59:21.271: IP: s=192.168.1.1 (Serial1/0), d=192.168.1.1 (Serial1/0), len 100, rcvd 3[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:21.279: IP: tableid=0, s=192.168.1.1 (local), d=192.168.1.1 (Serial1/0), routed via RIB[/font][/size]
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3 12:59:21.279: IP: s=192.168.1.1 (local), d=192.168.1.1 (Serial1/0), len 100, sending[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:21.343: IP: tableid=0, s=192.168.1.1 (Serial1/0), d=192.168.1.1 (Serial1/0), routed via RIB[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:21.343: IP: s=192.168.1.1 (Serial1/0), d=192.168.1.1 (Serial1/0), len 100, rcvd 3[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:21.347: IP: tableid=0, s=192.168.1.1 (local), d=192.168.1.1 (Serial1/0), routed via RIB[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:21.351: IP: s=192.168.1.1 (local), d=192.168.1.1 (Serial1/0), len 100, sending[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:21.415: IP: tableid=0, s=192.168.1.1 (Serial1/0), d=192.168.1.1 (Serial1/0), routed via RIB[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:21.415: IP: s=192.168.1.1 (Serial1/0), d=192.168.1.1 (Serial1/0), len 100, rcvd 3[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:21.419: IP: tableid=0, s=192.168.1.1 (local), d=192.168.1.1 (Serial1/0), routed via RIB[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:21.423: IP: s=192.168.1.1 (local), d=192.168.1.1 (Serial1/0), len 100, sending[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:21.463: IP: tableid=0, s=192.168.1.1 (Serial1/0), d=192.168.1.1 (Serial1/0), routed via RIB[/font][/size]
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3 12:59:21.463: IP: s=192.168.1.1 (Serial1/0), d=192.168.1.1 (Serial1/0), len 100, rcvd 3[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:21.467: IP: tableid=0, s=192.168.1.1 (local), d=192.168.1.1 (Serial1/0), routed via RIB[/font][/size]
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3 12:59:21.471: IP: s=192.168.1.1 (local), d=192.168.1.1 (Serial1/0), len 100, sending[/font][/size]
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3 12:59:21.535: IP: tableid=0, s=192.168.1.1 (Serial1/0), d=192.168.1.1 (Serial1/0), routed via RIB[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:21.535: IP: s=192.168.1.1 (Serial1/0), d=192.168.1.1 (Serial1/0), len 100, rcvd 3[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:21.539: IP: tableid=0, s=192.168.1.1 (local), d=192.168.1.1 (Serial1/0), routed via RIB[/font][/size]
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3 12:59:21.543: IP: s=192.168.1.1 (local), d=192.168.1.1 (Serial1/0), len 100, sending[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:21.607: IP: tableid=0, s=192.168.1.1 (Serial1/0), d=192.168.1.1 (Serial1/0), routed via RIB[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:21.607: IP: s=192.168.1.1 (Serial1/0), d=192.168.1.1 (Serial1/0), len 100, rcvd 3[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:21.611: IP: tableid=0, s=192.168.1.1 (local), d=192.168.1.1 (Serial1/0), routed via RIB[/font][/size]
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3 12:59:21.615: IP: s=192.168.1.1 (local), d=192.168.1.1 (Serial1/0), len 100, sending[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:21.631: IP: tableid=0, s=192.168.1.1 (Serial1/0), d=192.168.1.1 (Serial1/0), routed via RIB[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:21.631: IP: s=192.168.1.1 (Serial1/0), d=192.168.1.1 (Serial1/0), len 100, rcvd 3[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:21.635: IP: tableid=0, s=192.168.1.1 (local), d=192.168.1.1 (Serial1/0), routed via RIB[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:21.639: IP: s=192.168.1.1 (local), d=192.168.1.1 (Serial1/0), len 100, sending[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:21.703: IP: tableid=0, s=192.168.1.1 (Serial1/0), d=192.168.1.1 (Serial1/0), routed via RIB[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:21.707: IP: s=192.168.1.1 (Serial1/0), d=192.168.1.1 (Serial1/0), len 100, rcvd 3[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:21.707: IP: tableid=0, s=192.168.1.1 (local), d=192.168.1.1 (Serial1/0), routed via RIB[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:21.711: IP: s=192.168.1.1 (local), d=192.168.1.1 (Serial1/0), len 100, sending[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:21.991: IP: tableid=0, s=192.168.1.1 (Serial1/0), d=192.168.1.1 (Serial1/0), routed via RIB[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 12:59:21.991: IP: s=192.168.1.1 (Serial1/0), d=192.168.1.1 (Serial1/0), len 100, rcvd 3[/font][/size]
[size=9pt][font=Times New Roman][/font][/size]
[font=宋体][size=9pt]在这个实例中我们发现[/size][/font][size=9pt][font=Times New Roman]RB ping RA[/font][/size][font=宋体][size=9pt]所用的时间比[/size][/font][size=9pt][font=Times New Roman]RB ping[/font][/size][font=宋体][size=9pt]自己所用的时间几乎少了一半。为什么[/size][/font][size=9pt][font=Times New Roman]ping[/font][/size][font=宋体][size=9pt]自己的时间会比[/size][/font][size=9pt][font=Times New Roman]ping[/font][/size][font=宋体][size=9pt]对方的时间长呢？[/size][/font][size=9pt][/size]
[font=宋体][size=9pt]我们通过[/size][/font][size=9pt][font=Times New Roman]debug[/font][/size][font=宋体][size=9pt]信息可以发现，当[/size][/font][size=9pt][font=Times New Roman]RB ping[/font][/size][font=宋体][size=9pt]自己时，并不是按照我们想象的那样在自己的内部[/size][/font][size=9pt][font=Times New Roman]ping[/font][/size][font=宋体][size=9pt]，那是怎么回事呢？[/size][/font][size=9pt][/size]
[font=宋体][size=9pt]假想：[/size][/font][size=9pt][font=Times New Roman]ping[/font][/size][font=宋体][size=9pt]自身时，需要通过[/size][/font][size=9pt][font=Times New Roman]RA[/font][/size][font=宋体][size=9pt]。[/size][/font][size=9pt][/size]
[size=9pt][font=Times New Roman][/font][/size]
[font=宋体][size=9pt]这时我们如果将[/size][/font][size=9pt][font=Times New Roman]RA[/font][/size][font=宋体][size=9pt]的[/size][/font][size=9pt][font=Times New Roman]IP[/font][/size][font=宋体][size=9pt]地址去掉，[/size][/font][size=9pt][font=Times New Roman]RB[/font][/size][font=宋体][size=9pt]还能[/size][/font][size=9pt][font=Times New Roman]ping[/font][/size][font=宋体][size=9pt]通自己吗？如果不行，就验证了我们的假想[/size][/font][size=9pt][/size]
[size=9pt][font=Times New Roman]RA(config)#int s1/0[/font][/size]
[size=9pt][font=Times New Roman]RA(config-if)#no ip add[/font][/size]
[size=9pt][font=Times New Roman]RB#show cdp nei[/font][/size]
[font=Times New Roman][size=9pt]Capability Codes: R - Router, T - [/size][size=9pt]Trans[/size]
[size=9pt]Bridge[/size][size=9pt], B - [/size][size=9pt]Source[/size]
[size=9pt]Route[/size]
[size=9pt]Bridge[/size][size=9pt][/size][/font]
[size=9pt][font=Times New Roman]
S - Switch, H - Host, I - IGMP, r - Repeater[/font][/size]
[size=9pt][font=Times New Roman][/font][/size]
[size=9pt][font=Times New Roman]Device ID
Local Intrfce
Holdtme
Capability
Platform
Port ID[/font][/size]
[size=9pt][font=Times New Roman]RA
Ser 1/0
129
R
7206VXR
Ser 1/0[/font][/size]
[size=9pt][font=Times New Roman]RB#ping 192.168.1.2[/font][/size]
[size=9pt][font=Times New Roman][/font][/size]
[size=9pt][font=Times New Roman]Type escape sequence to abort.[/font][/size]
[size=9pt][font=Times New Roman]Sending 5, 100-byte ICMP Echos to 192.168.1.2, timeout is 2 seconds:[/font][/size]
[size=9pt][font=Times New Roman][/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 15:50:35.211: IP: tableid=0, s=192.168.1.2 (local), d=192.168.1.2 (Serial1/0), routed via RIB[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 15:50:35.215: IP: s=192.168.1.2 (local), d=192.168.1.2 (Serial1/0), len 100, sending.[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 15:50:37.211: IP: tableid=0, s=192.168.1.2 (local), d=192.168.1.2 (Serial1/0), routed via RIB[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 15:50:37.211: IP: s=192.168.1.2 (local), d=192.168.1.2 (Serial1/0), len 100, sending.[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 15:50:39.211: IP: tableid=0, s=192.168.1.2 (local), d=192.168.1.2 (Serial1/0), routed via RIB[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 15:50:39.211: IP: s=192.168.1.2 (local), d=192.168.1.2 (Serial1/0), len 100, sending.[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 15:50:41.211: IP: tableid=0, s=192.168.1.2 (local), d=192.168.1.2 (Serial1/0), routed via RIB[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 15:50:41.211: IP: s=192.168.1.2 (local), d=192.168.1.2 (Serial1/0), len 100, sending.[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 15:50:43.211: IP: tableid=0, s=192.168.1.2 (local), d=192.168.1.2 (Serial1/0), routed via RIB[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 15:50:43.215: IP: s=192.168.1.2 (local), d=192.168.1.2 (Serial1/0), len 100, sending.[/font][/size]
[size=9pt][font=Times New Roman]Success rate is 0 percent (0/5)[/font][/size]
[size=9pt][font=Times New Roman][/font][/size]
[font=宋体][size=9pt]此时无法[/size][/font][size=9pt][font=Times New Roman]ping[/font][/size][font=宋体][size=9pt]通，这样就验证了我们的假想，[/size][/font][size=9pt][font=Times New Roman]ping[/font][/size][font=宋体][size=9pt]自己要从对方那里走！[/size][/font][size=9pt][/size]
[size=9pt][font=Times New Roman][/font][/size]
[size=9pt][font=Times New Roman]TOPO2[/font][/size][font=宋体][size=9pt]：[/size][/font][size=9pt][/size]
[img]http://www.one-tom.com/bbs/uploads/gairuhe/2006-11-03_164744_topo2.jpg[/img]
[font=宋体][size=9pt]实验目的：验证[/size][/font][size=9pt][font=Times New Roman]ping[/font][/size][font=宋体][size=9pt]是一个双向过程[/size][/font][size=9pt][/size]
[font=宋体][size=9pt]配置：（[/size][/font][size=9pt][font=Times New Roman]ip[/font][/size][font=宋体][size=9pt]地址的配置省略）[/size][/font][size=9pt][/size]
[size=9pt][font=Times New Roman]RB(config)#ip route 192.168.2.0 255.255.255.0 192.168.1.1[/font][/size]
[size=9pt][font=Times New Roman]RB#ping 192.168.2.2[/font][/size]
[size=9pt][font=Times New Roman][/font][/size]
[size=9pt][font=Times New Roman]Type escape sequence to abort.[/font][/size]
[size=9pt][font=Times New Roman]Sending 5, 100-byte ICMP Echos to 192.168.2.2, timeout is 2 seconds:[/font][/size]
[size=9pt][font=Times New Roman][/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 16:30:41.147: IP: tableid=0, s=192.168.1.2 (local), d=192.168.2.2 (Serial1/0), routed via FIB[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 16:30:41.151: IP: s=192.168.1.2 (local), d=192.168.2.2 (Serial1/0), len 100, sending.[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 16:30:43.147: IP: tableid=0, s=192.168.1.2 (local), d=192.168.2.2 (Serial1/0), routed via FIB[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 16:30:43.147: IP: s=192.168.1.2 (local), d=192.168.2.2 (Serial1/0), len 100, sending.[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 16:30:45.147: IP: tableid=0, s=192.168.1.2 (local), d=192.168.2.2 (Serial1/0), routed via FIB[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 16:30:45.147: IP: s=192.168.1.2 (local), d=192.168.2.2 (Serial1/0), len 100, sending.[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 16:30:47.147: IP: tableid=0, s=192.168.1.2 (local), d=192.168.2.2 (Serial1/0), routed via FIB[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 16:30:47.147: IP: s=192.168.1.2 (local), d=192.168.2.2 (Serial1/0), len 100, sending.[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 16:30:49.147: IP: tableid=0, s=192.168.1.2 (local), d=192.168.2.2 (Serial1/0), routed via FIB[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 16:30:49.147: IP: s=192.168.1.2 (local), d=192.168.2.2 (Serial1/0), len 100, sending.[/font][/size]
[size=9pt][font=Times New Roman]Success rate is 0 percent (0/5)[/font][/size]
[size=9pt][font=Times New Roman]Ping[/font][/size][font=宋体][size=9pt]不通，但是[/size][/font][size=9pt][font=Times New Roman]debug[/font][/size][font=宋体][size=9pt]信息表示数据包已经发送成功[/size][/font][size=9pt][/size]
[font=宋体][size=9pt]在[/size][/font][size=9pt][font=Times New Roman]RC[/font][/size][font=宋体][size=9pt]上[/size][/font][size=9pt][/size]
[size=9pt][font=Times New Roman]RC#[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 16:30:01.219: IP: tableid=0, s=192.168.1.2 (Serial1/1), d=192.168.2.2 (Serial1/1), routed via RIB[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 16:30:01.219: IP: s=192.168.1.2 (Serial1/1), d=192.168.2.2 (Serial1/1), len 100, rcvd 3[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 16:30:01.223: IP: s=192.168.2.2 (local), d=192.168.1.2, len 100, unroutable[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 16:30:20.851: IP: tableid=0, s=192.168.1.2 (Serial1/1), d=192.168.2.2 (Serial1/1), routed via RIB[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 16:30:20.851: IP: s=192.168.1.2 (Serial1/1), d=192.168.2.2 (Serial1/1), len 100, rcvd 3[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 16:30:20.855: IP: s=192.168.2.2 (local), d=192.168.1.2, len 100, unroutable[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 16:30:22.771: IP: tableid=0, s=192.168.1.2 (Serial1/1), d=192.168.2.2 (Serial1/1), routed via RIB[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 16:30:22.771: IP: s=192.168.1.2 (Serial1/1), d=192.168.2.2 (Serial1/1), len 100, rcvd 3[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 16:30:22.775: IP: s=192.168.2.2 (local), d=192.168.1.2, len 100, unroutable[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 16:30:24.739: IP: tableid=0, s=192.168.1.2 (Serial1/1), d=192.168.2.2 (Serial1/1), routed via RIB[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 16:30:24.739: IP: s=192.168.1.2 (Serial1/1), d=192.168.2.2 (Serial1/1), len 100, rcvd 3[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 16:30:24.743: IP: s=192.168.2.2 (local), d=192.168.1.2, len 100, unroutable[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 16:30:26.803: IP: tableid=0, s=192.168.1.2 (Serial1/1), d=192.168.2.2 (Serial1/1), routed via RIB[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 16:30:26.803: IP: s=192.168.1.2 (Serial1/1), d=192.168.2.2 (Serial1/1), len 100, rcvd 3[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 16:30:26.807: IP: s=192.168.2.2 (local), d=192.168.1.2, len 100, unroutable[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 16:30:28.795: IP: tableid=0, s=192.168.1.2 (Serial1/1), d=192.168.2.2 (Serial1/1), routed via RIB[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 16:30:28.795: IP: s=192.168.1.2 (Serial1/1), d=192.168.2.2 (Serial1/1), len 100, rcvd 3[/font][/size]
[size=9pt][font=Times New Roman]*Nov
3 16:30:28.799: IP: s=192.168.2.2 (local), d=192.168.1.2, len 100, unroutable[/font][/size]
[font=宋体][size=9pt]提示没有路由，则在[/size][/font][size=9pt][font=Times New Roman]RC[/font][/size][font=宋体][size=9pt]上加上一下配置[/size][/font][size=9pt][/size]
[size=9pt][font=Times New Roman]RC(config)#ip route 192.168.1.0 255.255.255.0 192.168.2.1[/font][/size]
[size=9pt][font=Times New Roman]RB#ping 192.168.2.2[/font][/size]
[size=9pt][font=Times New Roman][/font][/size]
[size=9pt][font=Times New Roman]Type escape sequence to abort.[/font][/size]
[size=9pt][font=Times New Roman]Sending 5, 100-byte ICMP Echos to 192.168.2.2, timeout is 2 seconds:[/font][/size]
[size=9pt][font=Times New Roman]!!!!![/font][/size]
[size=9pt][font=Times New Roman]Success rate is 100 percent (5/5), round-trip min/avg/max = 96/160/224 ms[/font][/size]
[font=宋体][size=9pt]通了！[/size][/font][size=9pt][/size]
[size=9pt][font=Times New Roman][/font][/size]
[size=9pt][font=Times New Roman][/font][/size]
[font=宋体][size=9pt]这个实验告诉我们，当[/size][/font][size=9pt][font=Times New Roman]ping[/font][/size][font=宋体][size=9pt]对方不通的时候不一定是自己的问题，也许是对方主机上没有路由，需要到对方主机上核实信息。[/size][/font][size=9pt][/size]
[size=9pt][font=Times New Roman][/font][/size]
[size=9pt][font=Times New Roman][/font][/size]
[size=9pt][font=Times New Roman][/font][/size]
[size=9pt][font=Times New Roman][/font][/size]
[size=9pt][font=Times New Roman][/font][/size]
[size=12pt][font=Times New Roman]ping[/font][/size][font=宋体][size=12pt]命令作为最常用的检测设备间物理连通性的测试工具，在日常工作中大家都经常用到。我通过这几天的学习，将我所理解的[/size][/font][size=12pt][font=Times New Roman]ping[/font][/size][font=宋体][size=12pt]命令写下来供大家参考。有什么不足和错误的地方希望大家能告诉我。[/size][/font]
[font=宋体][size=12pt][size=2][font=宋体][size=10.5pt]参考文献：[/size][/font][size=10.5pt][/size][/size]
[size=2][size=10.5pt][font=Times New Roman]
ITAA[/font][/size][font=宋体][size=10.5pt]视频教程[/size][/font][size=10.5pt][/size][/size]
[size=2][size=10.5pt][font=Times New Roman]
[/font][/size][font=宋体][size=10.5pt]《思科网络技术学院教程（第一、二学期）》（第三版）[/size][/font][size=10.5pt][/size][/size]
[size=2][size=10.5pt][font=Times New Roman]
[/font][/size][font=宋体][size=10.5pt]《[/size][/font][size=10.5pt][font=Times New Roman]CCNA[/font][/size][font=宋体][size=10.5pt]学习指南》[/size][/font][size=10.5pt][/size][/size]
[size=2][size=10.5pt][font=Times New Roman]
[/font][/size][font=宋体][size=10.5pt]《[/size][/font][size=10.5pt][font=Times New Roman]Understanding the Ping Command[/font][/size][font=宋体][size=10.5pt]》[/size][/font][size=10.5pt][font=Times New Roman]
BY[/font][/size][font=宋体][size=10.5pt]：红头发[/size][/font][/size][size=10.5pt][/size]
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