实验15 基本的EIGRP配置 (CCIE实验43 P420)
时间：2006年2月10日 22:00-23:00
时间花费 总计约1小时
实验设备：2501 3台
实验拓扑：

需求：配置最基本的EIGRP路由，并且验证可行后继路由是否可以快速替换失效的后继。

参考资料：
Deploying IGRP/EIGRP
实验中值得记录的debug信息：
当R3将S1口shutdown之后，可以知道到达100.1.1.0/24的路由快速切换到通过e0口送出。此时如果再将S1口no shutdown，可以得到下面debug信息：
此时已经启动了debug ip routing, debug ip eigrp fsm, debug ip eigrp notifications
R3(config-if)#no shut
R3(config-if)#^Z
R3#
*Mar 1 21:43:52.194: is_up: 0 state: 4 sub state: 1 line: 0 has_route: False
*Mar 1 21:43:52.458: %SYS-5-CONFIG_I: Configured from console by console
*Mar 1 21:43:54.166: %LINK-3-UPDOWN: Interface Serial1, changed state to up
//端口打开
*Mar 1 21:43:54.174: is_up: 1 state: 4 sub state: 1 line: 0 has_route: False
*Mar 1 21:43:54.178: RT: add 1.1.1.0/30 via 0.0.0.0, connected metric [0/0]
*Mar 1 21:43:54.182: RT: NET-RED 1.1.1.0/30
//端口对应的直连路由进入到路由表
*Mar 1 21:43:54.186: IP-EIGRP(Default-IP-Routing-Table:0): Callback: redist con
nected (config change) Serial1
*Mar 1 21:43:54.186: RT: interface Serial1 added to routing table
//端口对应的直连路由进入到路由表
*Mar 1 21:43:54.190: IP-EIGRP(Default-IP-Routing-Table:64): Callback: route_adj
ust Serial1
//EIGRP发现应该开始对S1对应的路由做些事情了……
*Mar 1 21:43:54.194: is_up: 1 state: 4 sub state: 1 line: 0 has_route: True
*Mar 1 21:43:54.202: DUAL: dest(1.1.1.0/30) not active
*Mar 1 21:43:54.206: DUAL: rcvupdate: 1.1.1.0/30 via Connected metric 2169856/0
*Mar 1 21:43:54.210: DUAL: Find FS for dest 1.1.1.0/30. FD is 4294967295, RD is
4294967295 found
*Mar 1 21:43:54.214: DUAL: RT installed 1.1.1.0/30 via 0.0.0.0
//1.1.1.0/30通过本机可以到达
*Mar 1 21:43:54.218: DUAL: Send update about 1.1.1.0/30. Reason: metric chg
*Mar 1 21:43:54.222: DUAL: Send update about 1.1.1.0/30. Reason: new if
//准备发送关于1.1.1.0/30的路由更新
*Mar 1 21:43:55.170: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1, c
hanged state to up
*Mar 1 21:43:55.174: is_up: 1 state: 4 sub state: 1 line: 0 has_route: True
*Mar 1 21:43:55.770: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 64: Neighbor 1.1.1.2 (Seria
l1) is up: new adjacency
//与对端的R5建立起来了邻接关系(adjacency)
*Mar 1 21:43:58.562: DUAL: dest(4.4.4.0/30) not active
*Mar 1 21:43:58.566: DUAL: rcvupdate: 4.4.4.0/30 via 1.1.1.2 metric 2681856/2169856
*Mar 1 21:43:58.570: DUAL: Find FS for dest 4.4.4.0/30. FD is 2195456, RD is 2195456
*Mar 1 21:43:58.570: DUAL: 14.1.1.2 metric 2195456/2169856
*Mar 1 21:43:58.574: DUAL: 1.1.1.2 metric 2681856/2169856 found Dmin is 2195456
*Mar 1 21:43:58.578: DUAL: RT installed 4.4.4.0/30 via 14.1.1.2
//通过R5也收到了关于4.4.4.0/30的路由更新，这是由于R5上的S1口也在这个网段，并且在R5上作了通告
*Mar 1 21:43:58.586: DUAL: dest(100.1.1.0/24) not active
*Mar 1 21:43:58.586: DUAL: rcvupdate: 100.1.1.0/24 via 1.1.1.2 metric 2297856/128256
//通过R5收到了100.1.1.0/24的路由更新
*Mar 1 21:43:58.590: DUAL: Find FS for dest 100.1.1.0/24. FD is 2323456, RD is 2323456
*Mar 1 21:43:58.594: DUAL: 14.1.1.2 metric 2323456/2297856
*Mar 1 21:43:58.598: DUAL: 1.1.1.2 metric 2297856/128256 found Dmin is 2297856
//开始比较通过R4到100.1.1.0/24好，还是通过R5好。这里可以看到比较的过程Dmin is 2297856，那么显然通过1.1.1.2送数据更为合适
*Mar 1 21:43:58.602: DUAL: RT installed 100.1.1.0/24 via 14.1.1.2
//DUAL曰，该装100.1.1.0/24 via 14.1.1.2
*Mar 1 21:43:58.606: RT: del 100.1.1.0/24 via 14.1.1.2, eigrp metric [90/2323456]
//删除旧的路由
*Mar 1 21:43:58.610: RT: add 100.1.1.0/24 via 1.1.1.2, eigrp metric [90/2297856]
//添加新的路由
*Mar 1 21:43:58.614: RT: NET-RED 100.1.1.0/24
*Mar 1 21:43:58.618: DUAL: RT installed 100.1.1.0/24 via 1.1.1.2
//EIGRP得知路由已经成功装载
*Mar 1 21:43:58.622: DUAL: Send update about 100.1.1.0/24. Reason: metric chg
*Mar 1 21:43:58.626: DUAL: Send update about 100.1.1.0/24. Reason: new if
//R3自己也开始发送关于100.1.1.0/24的路由更新
*Mar 1 21:43:58.630: DUAL: dest(14.1.1.0/24) not active
*Mar 1 21:43:58.634: DUAL: rcvupdate: 14.1.1.0/24 via 1.1.1.2 metric 2707456/2195456
//从R5收到了关于14.1.1.0/24的路由更新
*Mar 1 21:43:58.638: DUAL: Find FS for dest 14.1.1.0/24. FD is 281600, RD is 281600
//目前到达14.1.1.0/24的FD是281600
*Mar 1 21:43:58.642: DUAL: 0.0.0.0 metric 281600/0
//现在是直连方式到达（即通过本机即可到达）
*Mar 1 21:43:58.642: DUAL: 1.1.1.2 metric 2707456/2195456 found Dmin is 281600
//通过另外一个路由器到达显然metric要大，比不了本机connected的
*Mar 1 21:44:00.842: DUAL: rcvupdate: 14.1.1.0/24 via 1.1.1.2 metric 4294967295/4294967295
//毒化路由的结果
*Mar 1 21:44:00.846: DUAL: Find FS for dest 14.1.1.0/24. FD is 281600, RD is 281600
*Mar 1 21:44:00.850: DUAL: 0.0.0.0 metric 281600/0
*Mar 1 21:44:00.854: DUAL: 1.1.1.2 metric 4294967295/4294967295 found Dmin is 281600
*Mar 1 21:44:00.858: DUAL: Removing dest 14.1.1.0/24, nexthop 1.1.1.2
//显然通过1.1.1.2(R5)到达是不现实的，直接remove掉