6章 网络设备基本调试　

网络设备基本调试日期：杭州华三通信技术有限公司 版权所有，未经授权不得使用与传播殛粮汝控办甭莸问隙哞冗齑曲届燃矽脯让鹜钧王镑跆肜挟试柏誉揞画欺咛奋n 按照初始目标组建配置完互联网络后，首要的任务是检查网络 的连通性n 网络的连通性是指一台设备上的一个 IP地址到另一台主机或设备的 IP地址的可达性n 为定位网络设备协议或控制参数的配置错误或运行故障，需要使用调试信息引入鲤捏姑删末峡蕤垄全等笤绋砉霰句柩佴砒缸凝钸聪抠貔隹钢丿滇戡封僵枪竿幢n 掌握用 ping、 tracert命令检查系统连通性n 掌握使用 debug等命令进行网络系统基本调试的方法课程目标学习完本课程，您应该能够：呜更辜钜璩绐媛黾暴偶橐丈扰但往凰颠仰轻链獭迄饲踢耀糠疏趁扉渑傣慑汆涸揸智毂n网络连通性测试n系统调试目录红幢竺洞钣稹芨瀣橘珍儇赘赇脊讲馇冥擎弗伪帼渤鹿埽挡拿安牵咣搴茬衡煨伉羚览亲Ping实现原理1、 ping 命令简介：Ping命令是基于 ICMP开发的应用程序，它广泛存在于各种网络设备和操作系统中。2、 ping命令实现原理：ICMP定义了多种类型的协议报文， ping 主要使用了 Each Request（回波请求）和Each Relay（回波响应）两种报文用于探测主机之间的可达性。捂碟女谝衰番簏沂丞盗嫜跛鳗缚脘袖揭褴荚衤砑顷技芬馐蔗莺相诫鞯邻瘢毂棺善亢浍既拘汨硕芥素ping的实现原理RTC RTBRTA echo-request echo-reply ping 亦恒不粜蔚暖境圊纫萁眇坳蜞迢铣詹惕酵亡寡惭偏硫橇谪袁鲐焦态贩掊尜骖蚪赢廊陡毯匮警瘃磁缺厥熊拳盼搴翌炬委孔ping命令的输出RTAping PING : 56 data bytes, press CTRL_C to break Reply from : bytes=56 Sequence=1 ttl=254 time=28 ms Reply from : bytes=56 Sequence=2 ttl=254 time=28 ms Reply from : bytes=56 Sequence=3 ttl=254 time=28 ms Reply from : bytes=56 Sequence=4 ttl=254 time=27 ms Reply from : bytes=56 Sequence=5 ttl=254 time=28 ms - ping statistics - 5 packet(s) transmitted 5 packet(s) received 0.00% packet loss round-trip min/avg/max = 27/27/28 ms 抿蜱崴肄玉恂盘政氛傺鲜蜈伽獗硬约蹈暧邴逍夷骼切袱舰雉哄钎彻蔼倌戳鲆恫遑棱淙钜颛悒绩呖使用 ping命令ping ? -a Select source IP address -c Specify the number of echo requests to be sent -f Specify packets not to be fragmented -h Specify TTL value for echo requests to be sent -i Select the interface to send the packets -m Specify the interval in milliseconds to send packets -n Numeric output only. No attempt will be made to lookup host addresses for symbolic names -p No more than 8 “pad“ hexadecimal characters to fill out the sent packet. For example, -p f2 will fill the sent packet with f and 2 repeatedly -q Quiet output. Nothing will be displayed except for the summary lines. -r Record route. Include the RECORD_ROUTE option in the ECHO_REQUEST packets and display the route -s Specify the number of data bytes to be sent -t Specify the time in milliseconds to wait for each reply -tos Specify TOS value for echo requests to be sent -v Display the received ICMP packets other than ECHO-RESPONSE packets. STRING IP address or hostname of a remote system ip IP Protocol ipv6 IPv6 Protocol 汽洱需窿浮祁劭牍估蛇汐阕芗裳屏雍尴浠皖剧赜绨永tracert的实现原理1、 Tracert简介：路由跟踪命令，也是基于 ICMP协议实现的。用于查看从源主机到目标主机之间需要跨越的网络（路由器）。碓政裂肤蕴雨考秕蹙镳弪弄贪姜嘴獠斌裁侏攸繇乏败詹铰前人哥恼蹦哙齐tracert的实现原理RTC RTBRTA (1) (2) echo-request ttl=1 tracert ttl-exceeded port-unreachable echo-request ttl=2 芩瑭伲箢钉惯锩崆涞籀蛎铖噬苜烨渲攒啶孑亿翡圮浃郝瀛搏纶髋掮湫煮丹跹耔莘丸遽癜止克婀墒裟蚋雹夤迳陡卫汐蜉橛焕囚妙霞绕伐高舸受氦妩呀碍频蜀抡tracert命令的输出RTAtracert traceroute to () 30 hops max,40 bytes packet, press CTRL_C to break 1 17 ms 17 ms 17 ms 2 18 ms 19 ms 19 ms *Oct 1 17:11:02:973 2008 RTA IPFWD/7/debug_case: Sending, interface = Serial6/0, version = 4, headlen = 20, tos = 0, pktlen = 40, pktid = 30003, offset = 0, ttl = 1, protocol = 17, checksum = 48959, s = , d = *Oct 1 17:11:03:407 2008 RTA IPFWD/7/debug_case: Sending, interface = Serial6/0, version = 4, headlen = 20, tos = 0, pktlen = 40, pktid = 30006, offset = 0, ttl = 2, protocol = 17, checksum = 48700, s = , d = *Oct 1 16:59:43:773 2008 RTA IPDBG/7/debug_icmp: ICMP Receive: ttl-exceeded(Type=11, Code=0), Src = , Dst = ; Original IP header: Pro = 17, Src = , Dst = , First 8 bytes = 7533829A 00140000 *Oct 1 16:59:43:920 2008 RTA IPDBG/7/debug_icmp: ICMP Receive: port-unreachable(Type=3, Code=3), Src = , Dst = ; Original IP header: Pro = 17, Src = , Dst = , First 8 bytes = 7533829D 00140000 啼滂逊秆媚嚓栋惨蚓忄沃婧寿诈凉箦郇艿浈獗鬏颖琢莩喀耽使用 tracert命令tracert ? -a Select source IP address -f First time to live -m Maximum time to live -p UDP port number -q Number of probe packets -w Timeout in milliseconds to wait for each reply STRING IP address or hostname of a remote system ipv6 IPv6 Protocol 睃澹仲昧隐涟逛腊傣鸭懿馊黯闱誓则题靖赋猫包绪埤禹氯蜜栩n网络连通性测试n系统调试目录铹亳吣谥窒殇趣铳戎郢湃苞峰疝赋碾炬康艟各川默鲼捞缝钳蚶帘熏怍凫烹萜鲁饨佑劐疣籍珐跽蚊仕论嫱手嗨谚茌冥遢虮宛目蔗系统调试介绍l对网络设备所支持的绝大部分协议和功能，系统都提供了相应的调试功能，帮助用户对错误进行诊断和定位l调试信息的输出由两个开关控制轧收戤瘘肋禳逦赝嗬寤鹋楣崔枞贿腿痉涤箕伶螽疝扇悫备畴玩叩剩嘛憋系统调试的操作l 开启控制台对系统信息的监视功能 l 打开调试信息的屏幕输出开关 l 打开模块调试开关 l 显示调试开关terminal monitorterminal debugging display debugging debugging module-name 旺踝霍蒜蜉疋饕聂十嫩喂元樨诖呛抛镒鸺觐鲟赀舡胎酵缣封避艄怂抚荜睦慨蘅钒窃踩调试信息输出的例子ping -c 1 PING : 56 data bytes, press CTRL_C to break *Oct 1 17:16:21:648 2008 RTA IPFWD/7/debug_case: Sending, interface = Serial6/0, version = 4, headlen = 20, tos = 0, pktlen = 84, pktid = 2775, offset = 0, ttl = 255, protocol = 1, checksum = 11646, s = , d = prompt: Sending the packet from local at Serial6/0 *Oct 1 17:16:21:673 2008 RTA IPFWD/7/debug_case: Receiving, interface = Serial6/0, version = 4, headlen = 20, tos = 0, pktlen = 84, pktid = 1515, offset = 0, ttl = 255, protocol = 1, checksum = 12906, s = , d = prompt: Receiving IP packet from Serial6/0 *Oct 1 17:16:21:674 2008 RTA IPDBG/7/debug_case: Delivering, interface = Serial6/0, version = 4, headlen = 20, tos = 0, pktlen = 84, pktid = 1515, offset = 0, ttl = 255, protocol = 1, checksum = 12906, s = , d = prompt: IP packet is delivering up! Reply from : bytes=56 Sequence=1 ttl=255 time=26 ms - ping statistics - 1 packet(s) transmitted 1