In the above figure, it is an instance of composite application of 6to4
tunnel and ISATAP tunnels. With the 6to4 tunnel technology, various
6to4 sites are interconnected and the 6to4 site accesses the Cernet
network via the 6to4 relay router. At the same time, with the ISATAP
tunnel technology inside the 6to4 site, the IPv6 hosts isolated by IPv4
inside the site perform IPv6 communication via the ISATAP tunnel.
In the above figure, the used global IP address containing the address of
the 6to4 Relay router is only for convenience. When actually planning
topologies, we should use a true global IP address and the address of
the 6to4 Relay. At present, many organizations provide open and free
6to4 Relay routers address.
The configurations of Area Border Routers in the 6to4 site shown in the above figure are
introduced respectively below. Please be noted that only main related configurations are
listed here.
RT-A Configuration:
# Connect the interfaces of the Internet
interface GigabitEthernet 0/1
no switchport
ip address 211.162.1.1 255.255.255.0
# Connect the interfaces of the IPv4 network inside the site
interface FastEthernet 0/1
no switchport
ip address 192.168.0.1 255.255.255.0
# Configure the ISATAP tunnel interface
interface Tunnel 1
tunnel mode ipv6ip isatap
tunnel source FastEthernet 0/1
ipv6 address 2002:d3a2:0101:1::/64 eui-64
no ipv6 nd suppress-ra
# Connect interface 1 of the IPv6 network
interface FastEthernet 0/2
no switchport
2002:d3a2:0101:10::1/64
# Connect interface 2 of the IPv6 network
interface FastEthernet 0/2
no switchport
2002:d3a2:0101:20::1/64
# Configure the 6to4 tunnel interface