实验需求：

• 每台路由器配置一个loopback口，四台路由器之间开启OSPF/ISIS，实现loopback口之间的通信；
• 每两台路由器之间的链路不能配置IPv6地址，直接使用link-local地址来实现链路之间的通信。

实验环境：

使用四台Cisco 2811路由器，IOS是目前最新的c2800nm-adventerprisek9-mz.151-4.M10.bin

实验步骤：

实验一、四台路由器之间开启OSPF：

1、配置loopback口和链路间的link-local地址：

R1#sh ipv6 int s 0/0/0
Serial0/0/0 is down, line protocol is down
IPv6 is tentative, link-local address is FE80::21B:54FF:FE0A:1878 [TEN] —— 
link-local地址
No Virtual link-local address(es):
No global unicast address is configured
Joined group address(es):
 FF02::1
 FF02::2
MTU is 1500 bytes
ICMP error messages limited to one every 100 milliseconds
ICMP redirects are enabled
ICMP unreachables are sent
ND DAD is enabled, number of DAD attempts: 1
ND reachable time is 30000 milliseconds (using 30000)
ND RAs are suppressed (periodic)
Hosts use stateless autoconfig for addresses.

link-local地址只在本链路有效，范围从FE80::/10 ~ FEBF::/10。

• 关于IPv6地址的其他范围，可以看这里《常用的IPv6地址汇总》
• 关于link-local地址如何自动生成，可以看这里《通过EUI-64自动生成IPv6/IPv6 link-local地址》

2、配置OSPF：

3、测试连通性：

R1#p 2::2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2::2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 0/2/4 ms

R1#p 3::3
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 3::3, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 0/1/4 ms

R1#p 4::4
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 4::4, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 0/2/4 ms

可以看到每台路由器的路由表非常精简，只有4条loopback口的IPv6地址的表项（和一个默认的组播地址表项）：

实验二、四台路由器之间开启ISIS：

1、配置link-local地址：（同实验一）

2、配置ISIS：

3、测试连通性：

R1#ping 1::1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 1::1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 0/0/0 ms

R1#ping 2::2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2::2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 0/1/4 ms

R1#ping 3::3
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 3::3, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 0/2/4 ms

R1#ping 4::4
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 4::4, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 0/0/4 ms

可以看到每台路由器的路由表非常精简，只有4条loopback口的IPv6地址的表项（和一个默认的组播地址表项）：