1、Overlay Tunnel解析
目前成都创新互联已为近1000家的企业提供了网站建设、域名、网页空间、网站运营、企业网站设计、密山网站维护等服务，公司将坚持客户导向、应用为本的策略，正道将秉承"和谐、参与、激情"的文化，与客户和合作伙伴齐心协力一起成长，共同发展。
2、实验拓扑
3、基础配置
R1配置
ipv6 unicast-routing
interface Loopback0
ipv6 address 1::1/64
interface FastEthernet1/0
ipv6 address 2000:12::1/64
R2配置
ipv6 unicast-routing
interface Loopback0
ip address 2.2.2.2 255.255.255.0
interface FastEthernet2/0
ip address 23.1.1.2 255.255.255.0
ip route 3.3.3.0 255.255.255.0 23.1.1.3
R3配置
ipv6 unicast-routing
interface Loopback0
ip address 3.3.3.3 255.255.255.0
interface FastEthernet2/0
ip address 23.1.1.3 255.255.255.0
ip route 2.2.2.0 255.255.255.0 23.1.1.2
R4配置
ipv6 unicast-routing
interface Loopback0
ipv6 address 4::4/64
interface FastEthernet1/0
ipv6 address 2000:34::4/64
4、配置Overlay Tunnel
R1配置
interface Loopback0
ipv6 ospf 110 area 0
interface FastEthernet1/0
ipv6 ospf 110 area 0
ipv6 router ospf 110
router-id 1.1.1.1
R2配置
interface Tunnel2
ipv6 enable
ipv6 ospf 110 area 0
tunnel source 2.2.2.2
tunnel destination 3.3.3.3
tunnel mode ipv6ip
interface FastEthernet1/0
ipv6 ospf 110 area 0
ipv6 router ospf 110
router-id 2.2.2.2
R3配置
interface Tunnel3
ipv6 enable
ipv6 ospf 110 area 0
tunnel source 3.3.3.3
tunnel destination 2.2.2.2
tunnel mode ipv6ip
interface FastEthernet1/0
ipv6 ospf 110 area 0
ipv6 router ospf 110
router-id 3.3.3.3
R4配置
interface Loopback0
ipv6 ospf 110 area 0
interface FastEthernet1/0
ipv6 ospf 110 area 0
ipv6 router ospf 110
router-id 4.4.4.4
5、实验测试
此时方法的不足之处在于，当有多个IPv6网络需要互访是，我们需要两两之间都建立Tunnel，工作量将非常大。
