GRE VPN——配置实验
1，按照图示配置IP地址
r1：
r2：
r3：
2，在R1和R3配置默认路由使公网区域互通
[R1]ip route-static 0.0.0.0 0 100.1.1.2
R3]ip route-static 0.0.0.0 0 100.2.2.2
3，在R1和R3上配置GRE VPN，使两端私网能够互相访问，Tunnel口IP地址如图,隧道双up：
[R1-Tunnel0/0/0]tunnel-protocol gre
[R1-Tunnel0/0/0]source 100.1.1.1
[R1-Tunnel0/0/0]destination 100.2.2.3[R3-Tunnel0/0/0]tunnel-protocol gre
[R3-Tunnel0/0/0]source 100.2.2.3
[R3-Tunnel0/0/0]destination 100.1.1.1<R1>ping -a 192.168.3.1 192.168.3.3PING 192.168.3.3: 56 data bytes, press CTRL_C to breakRequest time outReply from 192.168.3.3: bytes=56 Sequence=2 ttl=255 time=40 msReply from 192.168.3.3: bytes=56 Sequence=3 ttl=255 time=30 msReply from 192.168.3.3: bytes=56 Sequence=4 ttl=255 time=30 msReply from 192.168.3.3: bytes=56 Sequence=5 ttl=255 time=20 ms--- 192.168.3.3 ping statistics ---5 packet(s) transmitted4 packet(s) received20.00% packet lossround-trip min/avg/max = 20/30/40 ms4，在R1和R3上配置RIPV2来传递两端私网路由
[R1]ip route-static 192.168.2.0 24 192.168.3.3
[R3]ip route-static 192.168.1.0 24 192.168.3.1
<R3>ping 192.168.1.1PING 192.168.1.1: 56 data bytes, press CTRL_C to breakRequest time outReply from 192.168.1.1: bytes=56 Sequence=2 ttl=127 time=20 msReply from 192.168.1.1: bytes=56 Sequence=3 ttl=127 time=30 msReply from 192.168.1.1: bytes=56 Sequence=4 ttl=127 time=30 msReply from 192.168.1.1: bytes=56 Sequence=5 ttl=127 time=20 ms--- 192.168.1.1 ping statistics ---5 packet(s) transmitted4 packet(s) received20.00% packet lossround-trip min/avg/max = 20/25/30 ms