实验拓扑如下：
环境概述：
PC1和PC2与路由器之间为IPv4网络。两台路由器之间为IPv6网络，通过配置，要求是PC1与PC2能互通。即使IPv4可以在IPv6网络中通信。
配置方法：
AR1：
ipv6
interface GigabitEthernet0/0/0
ip address 192.168.1.1 255.255.255.0
interface GigabitEthernet0/0/1
ipv6 enable
ipv6 address 2019:1::1/64
interface Tunnel0/0/0
ip address 10.1.1.1 255.255.255.0
tunnel-protocol ipv4-ipv6
source 2019:1::1
destination 2019:1::2
ip route-static 192.168.2.0 255.255.255.0 Tunnel0/0/0
AR2:
ipv6
interface GigabitEthernet0/0/0
ipv6 enable
ipv6 address 2019:1::2/64
interface GigabitEthernet0/0/1
ip address 192.168.2.1 255.255.255.0
interface Tunnel0/0/0
ip address 10.1.1.2 255.255.255.0
tunnel-protocol ipv4-ipv6
source 2019:1::2
destination 2019:1::1
ip route-static 192.168.1.0 255.255.255.0 Tunnel0/0/0
抓包分析：
