TCP/IP 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