point-to-multipoint的tunnel来实现6to4，但必须要求使用6to4的ipv6地址(2002::/16)。
R1
hostname R1
!
ipv6 unicast-routing
!
interface Ethernet1/4
no ip address
duplex full
ipv6 address 2002:404:404:104::1/64
ipv6 enable
!
ipv6 route ::/0 2002:404:404:104::4
R2
hostname R2
!
ipv6 unicast-routing
!
interface Ethernet1/5
no ip address
duplex full
ipv6 address 2002:505:505:205::2/64
ipv6 enable
!
ipv6 route ::/0 2002:505:505:205::5
R3
hostname R3
!
ipv6 unicast-routing
!
interface Ethernet1/6
no ip address
duplex full
ipv6 address 2002:606:606:306::3/64
ipv6 enable
!
ipv6 route ::/0 2002:606:606:306::6
R4
hostname R4
!
ipv6 unicast-routing
!
interface Loopback0
ip address 4.4.4.4 255.255.255.255
!
interface Tunnel0
no ip address
no ip redirects
ipv6 address 2002:404:404::4/128
ipv6 enable
tunnel source 4.4.4.4
tunnel mode ipv6ip 6to4
!
interface Ethernet1/1
no ip address
duplex full
ipv6 address 2002:404:404:104::4/64
!
interface Ethernet1/7
ip address 192.168.47.4 255.255.255.0
duplex full
!
router ospf 100
router-id 4.4.4.4
log-adjacency-changes
redistribute connected subnets
redistribute static subnets
network 192.168.0.0 0.0.255.255 area 0
!
ipv6 route 2002::/16 Tunnel0
ipv6 route ::/0 2002:404:404:104::1
R5
hostname R5
!
ipv6 unicast-routing
!
interface Loopback0
ip address 5.5.5.5 255.255.255.255
!
interface Tunnel0
no ip address
no ip redirects
ipv6 address 2002:505:505::5/128
ipv6 enable
tunnel source 5.5.5.5
tunnel mode ipv6ip 6to4
!
interface Ethernet1/2
no ip address
duplex full
ipv6 address 2002:505:505:205::5/64
ipv6 enable
!
interface Ethernet1/7
ip address 192.168.57.5 255.255.255.0
duplex full
!
router ospf 100
router-id 5.5.5.5
log-adjacency-changes
redistribute connected subnets
redistribute static subnets
network 192.168.0.0 0.0.255.255 area 0
!
ipv6 route 2002::/16 Tunnel0
ipv6 route ::/0 2002:505:505:205::2
R6
hostname R6
!
ipv6 unicast-routing
!
interface Loopback0
ip address 6.6.6.6 255.255.255.255
!
interface Tunnel0
no ip address
no ip redirects
ipv6 address 2002:606:606::6/128
ipv6 enable
tunnel source 6.6.6.6
tunnel mode ipv6ip 6to4
!
interface Ethernet1/3
no ip address
duplex full
ipv6 address 2002:606:606:306::6/64
ipv6 enable
!
interface Ethernet1/7
ip address 192.168.67.6 255.255.255.0
duplex full
!
router ospf 100
router-id 6.6.6.6
log-adjacency-changes
redistribute connected subnets
redistribute static subnets
network 192.168.0.0 0.0.255.255 area 0
!
ipv6 route 2002::/16 Tunnel0
ipv6 route ::/0 2002:606:606:306::3
R7
hostname R7
!
interface Loopback0
ip address 7.7.7.7 255.255.255.255
!
interface Ethernet1/4
ip address 192.168.47.7 255.255.255.0
duplex full
!
interface Ethernet1/5
ip address 192.168.57.7 255.255.255.0
duplex full
!
interface Ethernet1/6
ip address 192.168.67.7 255.255.255.0
duplex full
!
router ospf 100
router-id 7.7.7.7
log-adjacency-changes
redistribute connected subnets
redistribute static subnets
network 192.168.0.0 0.0.255.255 area 0