Win7单网卡做单臂路由转发测试

一.测试拓扑

二.基本配置
1.Win7的一个网卡配置两个网段的IP

2.R1路由器
hostname R1
interface Ethernet0/0
ip address 192.168.10.8 255.255.255.0
no shutdown
3.R2路由器
hostname R2
interface Ethernet0/0
ip address 202.100.1.8 255.255.255.0
no shutdown
三.路由器配置
1.Win7开启路由转发

2.R1配置默认路由或静态路由
ip route 0.0.0.0 0.0.0.0 192.168.10.10
或者
ip route 202.100.1.0 255.255.255.0 192.168.10.10
3.R2配置默认路由或静态路由
ip route 0.0.0.0 0.0.0.0 202.100.1.10
或者
ip route 192.168.1.0 255.255.255.0 202.100.1.10
四.测试
1.因为Win7没有关闭防火墙，所以R1无法ping通Win7的直连地址
R1#ping 202.100.1.10
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 202.100.1.10, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)
R1#
2.R1可以ping通R2的地址
R1#ping 202.100.1.8
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 202.100.1.8, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/2 ms
R1#
3.如果提前在R2上开启debug，可以看到显示的日志
R2#debug ip icmp
ICMP packet debugging is on
Dec 9 02:44:09.989: ICMP: echo reply sent, src 202.100.1.8, dst 192.168.10.8, topology BASE, dscp 0 topoid 0
Dec 9 02:44:09.989: ICMP: bogus redirect from 202.100.1.10 - for 192.168.10.8 use gw 192.168.10.8
Dec 9 02:44:09.989: gateway address on different subnet
Dec 9 02:44:09.989: ICMP: echo reply sent, src 202.100.1.8, dst 192.168.10.8, topology BASE, dscp 0 topoid 0
Dec 9 02:44:09.990: ICMP: echo reply sent, src 202.100.1.8, dst 192.168.10.8, topology BASE, dscp 0 topoid 0
Dec 9 02:44:09.990: ICMP: echo reply sent, src 202.100.1.8, dst 192.168.10.8, topology BASE, dscp 0 topoid 0
R2#
*Dec 9 02:44:09.991: ICMP: echo reply sent, src 202.100.1.8, dst 192.168.10.8, topology BASE, dscp 0 topoid 0
R2#
备注：从日志可以看出，因为数据包从Win7相同网卡进出，所以Win7发出了网络重定向的ICMP包，但是R2收到之后，因为判断地址与自己的地址不在相同网段，所以忽略掉了。