华为数通操作手册 VRP全系列 VRP故障处理手册 路由器 任务包2.3-EIGRP的Ip-default network

Ip default network 实验目的 验证实验目的 验证 ip default network 的工作原理及实验过的工作原理及实验过 程程 实验拓扑 实验拓扑 R1R2R3 Lo 2 2 2 2 24 S2 0S1 0S2 0S1 0 网络边界网络边界 实验过程 实验过程 基本配置基本配置 R1 hostname R1 interface Loopback0 ip address 1 1 1 1 255 255 255 0 interface Serial1 0 ip address 12 1 1 1 255 255 255 0 serial restart delay 0 R2 hostname R2 interface Loopback0 ip address 2 2 2 2 255 255 255 0 Lo 1 1 1 1 2412 1 1 0 2423 1 1 0 24Lo 3 3 3 3 24 interface Serial1 0 ip address 23 1 1 2 255 255 255 0 serial restart delay 0 interface Serial2 0 ip address 12 1 1 2 255 255 255 0 serial restart delay 0 R3 hostname R3 interface Loopback0 ip address 3 3 3 3 255 255 255 0 interface Serial2 0 ip address 23 1 1 3 255 255 255 0 serial restart delay 0 实验配置实验配置 R1 router eigrp 100 network 1 1 1 0 0 0 0 255 network 12 1 1 0 0 0 0 255 auto summary R2 router eigrp 100 network 12 1 1 0 0 0 0 255 network 23 1 1 0 0 0 0 255 想想其特别之处 auto summary ip classless ip default network 23 0 0 0 通告默认路由配置 ip route 0 0 0 0 0 0 0 0 23 1 1 3 与外网通信的静态默认路由配置 no ip http server no ip http secure server R3 ip classless ip route 0 0 0 0 0 0 0 0 23 1 1 2 与内网通信的静态路由配置 通信是双向的 no ip http server no ip http secure server 实验结论 实验结论 1 实验详细说明 此实验是用 R1 模拟内网 R2 和 R3 模拟网络边界 把 R1 和 R2 运行在 EIGRP 100 内 R2 和 R3 之间的通信是通过设置静态默认路由实现 R1 与外网通信是通过 R2 通告的 EIGRP 默认路由完成的 R1 与所有未知目的网段的通信都会通过 R2 实现 即 R1 要实现与外界 的通信 若路由表中没有目的网段的路由 则会把包掷给 R2 2 以上实验配置得出的实验信息 R1 sh ip route Gateway of last resort is 12 1 1 2 to network 23 0 0 0 1 0 0 0 8 is variably subnetted 2 subnets 2 masks C 1 1 1 0 24 is directly connected Loopback0 D 1 0 0 0 8 is a summary 00 07 54 Null0 D 23 0 0 0 8 90 2681856 via 12 1 1 2 00 06 48 Serial1 0 12 0 0 0 8 is variably subnetted 2 subnets 2 masks C 12 1 1 0 24 is directly connected Serial1 0 D 12 0 0 0 8 is a summary 00 07 54 Null0 R2 sh ip route Gateway of last resort is 23 1 1 3 to network 0 0 0 0 D 1 0 0 0 8 90 2297856 via 12 1 1 1 00 09 12 Serial2 0 2 0 0 0 24 is subnetted 1 subnets C 2 2 2 0 is directly connected Loopback0 23 0 0 0 8 is variably subnetted 2 subnets 2 masks C 23 1 1 0 24 is directly connected Serial1 0 D 23 0 0 0 8 is a summary 00 09 01 Null0 12 0 0 0 8 is variably subnetted 2 subnets 2 masks C 12 1 1 0 24 is directly connected Serial2 0 D 12 0 0 0 8 is a summary 00 09 01 Null0 S 0 0 0 0 0 1 0 via 23 1 1 3 R3 sh ip route Gateway of last resort is 23 1 1 2 to network 0 0 0 0 3 0 0 0 24 is subnetted 1 subnets C 3 3 3 0 is directly connected Loopback0 23 0 0 0 24 is subnetted 1 subnets C 23 1 1 0 is directly connected Serial2 0 S 0 0 0 0 0 1 0 via 23 1 1 2 R1 ping 3 3 3 3 sou 1 1 1 1 Type escape sequence to abort Sending 5 100 byte ICMP Echos to 3 3 3 3 timeout is 2 seconds Packet sent with a source address of 1 1 1 1 Success rate is 100 percent 5 5 round trip min avg max 40 40 40 ms R1 ping 2 2 2 2 sou 1 1 1 1 Type escape sequence to abort Sending 5 100 byte ICMP Echos to 2 2 2 2 timeout is 2 seconds Packet sent with a source address of 1 1 1 1 Success rate is 100 percent 5 5 round trip min avg max 20 20 20 ms 3 以上仅是做出想得到正确的实验结果的配置及实验信息 可能会很容易发现实验配置 和相应实验信息的一些条目被高亮显示 下面将针对这些被标注部分及可能存在的一 些疑问进行具体分析 疑问一 R2 中的一条配置 network 23 1 1 0 0 0 0 255 对于这条配置可以与 RIP 默认路由实验中的相应配置作比较 在 RIP 的默认路由实验中 与外界路由器相连的那个网段 23 1 1 0 24 是不需要通告的 但是在 EIGRP 中是必须通告的 如果不通告这个网段 会出现下面的不同现象 R1 sh ip route Gateway of last resort is not set 1 0 0 0 8 is variably subnetted 2 subnets 2 masks C 1 1 1 0 24 is directly connected Loopback0 D 1 0 0 0 8 is a summary 00 07 12 Null0 12 0 0 0 8 is variably subnetted 2 subnets 2 masks C 12 1 1 0 24 is directly connected Serial1 0 D 12 0 0 0 8 is a summary 00 07 12 Null0 R2 sh ip route Gateway of last resort is 23 1 1 3 to network 0 0 0 0 D 1 0 0 0 8 90 2297856 via 12 1 1 1 00 08 11 Serial2 0 2 0 0 0 24 is subnetted 1 subnets C 2 2 2 0 is directly connected Loopback0 23 0 0 0 24 is subnetted 1 subnets C 23 1 1 0 is directly connected Serial1 0 12 0 0 0 24 is subnetted 1 subnets C 12 1 1 0 is directly connected Serial2 0 S 0 0 0 0 0 1 0 via 23 1 1 3 可以发现与 2 中显示的路由条目相比 绿色条目消失了 橙色部分也有不同 默认路由设 置不成功 当然 R1 与 R3 是不通的 R1 ping 3 3 3 3 Type escape sequence to abort Sending 5 100 byte ICMP Echos to 3 3 3 3 timeout is 2 seconds Success rate is 0 percent 0 5 那么为什么 R3 必须要通告 23 1 1 0 24 这个网段而 RIP 不需要呢 我认为可以从 EIGRP 的 三张表想一下 具体细节请读者自行研究 疑问二 实验配置中 R1 和 R2 中的蓝色条目 auto summary 此实验是在没有关闭 R1 和 R2 的自动汇总前提下进行的 那若关闭自动汇总呢 会一切照 常 还是会出现一些其他现象呢 在关闭 R1 和 R2 的 EIGRP 自动汇总后 其余配置不变 仅在原实验配置基础上关闭 auto summary R1 和 R2 路由表显示路由信息如下 R1 sh ip route Gateway of last resort is 12 1 1 2 to network 0 0 0 0 1 0 0 0 24 is subnetted 1 subnets C 1 1 1 0 is directly connected Loopback0 23 0 0 0 24 is subnetted 1 subnets D 23 1 1 0 90 2681856 via 12 1 1 2 00 05 08 Serial1 0 12 0 0 0 24 is subnetted 1 subnets C 12 1 1 0 is directly connected Serial1 0 R2 sh ip route Gateway of last resort is 23 1 1 3 to network 0 0 0 0 1 0 0 0 24 is subnetted 1 subnets D 1 1 1 0 90 2297856 via 12 1 1 1 00 06 18 Serial2 0 2 0 0 0 24 is subnetted 1 subnets C 2 2 2 0 is directly connected Loopback0 23 0 0 0 24 is subnetted 1 subnets C 23 1 1 0 is directly connected Serial1 0 12 0 0 0 24 is subnetted 1 subnets C 12 1 1 0 is directly connected Serial2 0 S 0 0 0 0 0 1 0 via 23 1 1 3 可以发现与原实验显示的不同之处了 当然 R1 去 ping 3 3 3 3 是不通的 可以发现 R2 路 由表中缺少了这个条目 D 23 0 0 0 8 is a summary 00 09 01 Null0 这是关闭自动汇总后导致结果不同的直接原因 那么从这点可以看出 R2 必须开启 auto summary 下面是关闭 R1 auto summary 开启 R2 auto summary 下 R1 和 R2 的路由表中的 信息 R1 sh ip route Gateway of last resort is 12 1 1 2 to network 23 0 0 0 1 0 0 0 24 is subnetted 1 subnets C 1 1 1 0 is directly connected Loopback0 D 23 0 0 0 8 90 2681856 via 12 1 1 2 00 01 41 Serial1 0 12 0 0 0 24 is subnetted 1 subnets C 12 1 1 0 is directly connected Serial1 0 R2 sh ip route Gateway of last resort is 23 1 1 3 to network 0 0 0 0 1 0 0 0 24 is subnetted 1 subnets D 1 1 1 0 90 2297856 via 12 1 1 1 00 02 32 Serial2 0 2 0 0 0 24 is subnetted 1 subnets C 2 2 2 0 is directly connected Loopback0 23 0 0 0 8 is variably subnetted 2 subnets 2 masks C 23 1 1 0 24 is directly connected Serial1 0 D 23 0 0 0 8 is a summary 00 02 37 Null0 12 0 0 0 8 is variably subnetted 2 subnets 2 masks C 12 1 1 0 24 is directly connected Serial2 0 D 12 0 0 0 8 is a summary 00 02 37 Null0 S 0 0 0 0 0 1 0 via 23 1 1 3 疑问三 上面疑问二中说明 R2 必须开始 auto summary 那么若 R2 必须关闭 auto summary 呢 应该如何在这种情况下做配置呢 以下提供一种解决方法 R1 实验配置 router eigrp 100 network 1 1 1 0 0 0 0 255 network 12 1 1 0 0 0 0 255 no auto summary R2 实验配置 router eigrp 100 redistribute static network 12 1 1 0 0 0 0 255 network 23 1 1 0 0 0 0 255 注意 这条配置可以取消 再次引发思考 这里与疑问 一中问题的不同之处 no auto summary ip classless ip route 0 0 0 0 0 0 0 0 23 1 1 3 注意 没有了 ip default network 23 0 0 0 的配置 no ip http server no ip http secure server R3 实验配置不变 R1 sh ip route Gateway of last resort is 12 1 1 2 to network 0 0 0 0 1 0 0 0 24 is subnetted 1 subnets C 1 1 1 0 is directly connected Loopback0 23 0 0 0 24 is subnetted 1 subnets D 23 1 1 0 90 2681856 via 12 1 1 2 00 02 14 Serial1 0 12 0 0 0 24 is subnetted 1 subnets C 12 1 1 0 is directly connected Serial1 0 D EX 0 0 0 0