TCP/IP 5.3.4不连续的子网和无类别路由选择
5.3.4
不连续的子网和无类别路由选择
温习：有类别路由选择：在边界路由器上的路由汇总
处在两个主网络边界上的路由器不会把其中一个主网络的子网通告给另一个主网。
看图
RIPV2
在缺省情况下是会在主网络边界上进行路由汇总的
但是这里可以关闭这个功能
no auto-summary
还有之前看到的不连续子网的问题，在
RIPV1
的时候
那个时候是用辅助地址的方法来解决的
现在路由协议能支持不连续子网，就可以解决这个问题了，不要用辅助地址的方式来解决
即是
VLSM
也是不连续子网
配置和
net
文件在附件里面呀
用
RIPV2
的方式来看
第一、不能让她在主网络边界上进行路由汇总，
VLSM
对他没有影响，子网能够过去了。
第二、
RIPV2
是无类别路由选择协议，他会在目的地址和所有已知路由之间逐位执行最佳匹配。不连续对他没有影响。
（有类：就是按照
IP
地址的分类来分类了，无类就是没有
IP
地址类别这个概念仅仅是逐位执行最佳匹配）
查看
RIP v2
路由表
2
个
10
段的子网是认出来了。知道该怎么走的
在
RIPV1
的时候
是这个情况
有类路由就是这样的
2
个子网被他认成是一个网段
现在来配置
VER2
Andy#debug ip rip
RIP protocol debugging is on
Andy#
*Apr 19 23:33:26.147: RIP: sending v2 update to 224.0.0.9 via Loopback0 (192.168.12.65)
*Apr 19 23:33:26.147: RIP: build update entries
*Apr 19 23:33:26.151: 10.33.0.0/20 via 0.0.0.0, metric 2, tag 0
*Apr 19 23:33:26.151: 192.168.12.192/27 via 0.0.0.0, metric 1, tag 0
*Apr 19 23:33:26.155: 192.168.83.0/24 via 0.0.0.0, metric 1, tag 0
*Apr 19 23:33:26.155: RIP: ignored v2 packet from 192.168.12.65 (sourced from one of our addresses)
*Apr 19 23:33:26.499: RIP: sending v2 update to 224.0.0.9 via FastEthernet0/1 (192.168.12.195)
*Apr 19 23:33:26.499: RIP: build update entries
*Apr 19 23:33:26.503: 10.33.0.0/20 via 0.0.0.0, metric 2, tag 0
*Apr 19 23:33:26.503: 192.168.12.64/27 via 0.0.0.0, metric 1, tag 0
*Apr 19 23:33:26.507: 192.168.83.0/24 via 0.0.0.0, metric 1, tag 0
Andy#
*Apr 19 23:33:31.615: RIP: received v2 update from 192.168.12.196 on FastEthernet0/1
*Apr 19 23:33:31.619: 10.33.32.0/20 via 0.0.0.0 in 1 hops
Andy#
*Apr 19 23:33:33.619: RIP: sending v2 flash update to 224.0.0.9 via FastEthernet0/1 (192.168.12.195)
*Apr 19 23:33:33.619: RIP: build flash update entries - suppressing null update
*Apr 19 23:33:33.623: RIP: sending v2 flash update to 224.0.0.9 via Loopback0 (192.168.12.65)
*Apr 19 23:33:33.623: RIP: build flash update entries
*Apr 19 23:33:33.627: 10.33.32.0/20 via 0.0.0.0, metric 2, tag 0
*Apr 19 23:33:33.627: RIP: sending v2 flash update to 224.0.0.9 via FastEthernet0/0 (192.168.83.1)
*Apr 19 23:33:33.631: RIP: build flash update entries
*Apr 19 23:33:33.631: 10.33.32.0/20 via 0.0.0.0, metric 2, tag 0
Andy#
*Apr 19 23:33:33.639: RIP: ignored v2 packet from 192.168.12.65 (sourced from one of our addresses)
Andy#
*Apr 19 23:33:40.199: RIP: received v2 update from 192.168.83.244 on FastEthernet0/0
*Apr 19 23:33:40.203: 10.33.0.0/20 via 0.0.0.0 in 1 hops
Andy#un all
All possible debugging has been turned off
VER1
Andy#debug ip rip
RIP protocol debugging is on
Andy#
*Apr 19 23:37:02.427: RIP: sending v1 update to 255.255.255.255 via FastEthernet0/0 (192.168.83.1)
*Apr 19 23:37:02.427: RIP: build update entries
*Apr 19 23:37:02.431: network 10.0.0.0 metric 2
*Apr 19 23:37:02.431: network 192.168.12.0 metric 1
Andy#
*Apr 19 23:37:10.487: RIP: sending v1 update to 255.255.255.255 via Loopback0 (192.168.12.65)
*Apr 19 23:37:10.487: RIP: build update entries
*Apr 19 23:37:10.491: network 10.0.0.0 metric 2
*Apr 19 23:37:10.491: subnet 192.168.12.192 metric 1
*Apr 19 23:37:10.491: network 192.168.83.0 metric 1
Andy#
*Apr 19 23:37:11.731: RIP: received v1 update from 192.168.12.196 on FastEthernet0/1
*Apr 19 23:37:11.735: 10.0.0.0 in 1 hops
Andy#
*Apr 19 23:37:12.995: RIP: sending v1 update to 255.255.255.255 via FastEthernet0/1 (192.168.12.195)
*Apr 19 23:37:12.995: RIP: build update entries
*Apr 19 23:37:12.999: network 10.0.0.0 metric 2
*Apr 19 23:37:12.999: subnet 192.168.12.64 metric 1
*Apr 19 23:37:13.003: network 192.168.83.0 metric 1
*Apr 19 23:37:13.735: RIP: sending v1 flash update to 255.255.255.255 via FastEthernet0/1 (192.168.12.195)
*Apr 19 23:37:13.735: RIP: build flash update entries - suppressing null update
*Apr 19 23:37:13.739: RIP: sending v1 flash update to 255.255.255.255 via Loopback0 (192.168.12.65)
*Apr 19 23:37:13.739: RIP: build flash update entries - suppressing null update
Andy#
*Apr 19 23:37:13.743: RIP: sending v1 flash update to 255.255.255.255 via FastEthernet0/0 (192.168.83.1)
*Apr 19 23:37:13.747: RIP: build flash update entries - suppressing null update
Andy#
*Apr 19 23:37:18.591: RIP: received v1 update from 192.168.83.244 on FastEthernet0/0
*Apr 19 23:37:18.595: 10.0.0.0 in 1 hops
Andy#
*Apr 19 23:37:30.723: RIP: sending v1 update to 255.255.255.255 via FastEthernet0/0 (192.168.83.1)
*Apr 19 23:37:30.723: RIP: build update entries
*Apr 19 23:37:30.723: network 10.0.0.0 metric 2
*Apr 19 23:37:30.723: network 192.168.12.0 metric 1
Andy#un all
All possible debugging has been turned off
华丽丽的对比
这个是
RIPV2
的其中的一条信息
*Apr 19 23:33:33.627: RIP: sending v2 flash update to 224.0.0.9 via FastEthernet0/0 (192.168.83.1)
*Apr 19 23:33:33.631: RIP: build flash update entries
*Apr 19 23:33:33.631: 10.33.32.0/20 via 0.0.0.0, metric 2, tag 0
这个是
RIPV1
其中的一条信息
*Apr 19 23:37:02.427: RIP: sending v1 update to 255.255.255.255 via FastEthernet0/0 (192.168.83.1)
*Apr 19 23:37:02.427: RIP: build update entries
*Apr 19 23:37:02.431: network 10.0.0.0 metric 2