前提

・PE-CE接続はOSPF
・CEのgi0/2どうしの接続はbackup用

Before

iosv-2#sh ip route ospf | b Gate
Gateway of last resort is not set

      11.0.0.0/32 is subnetted, 1 subnets
O E2     11.11.11.11 [110/1] via 12.1.1.1, 00:06:43, GigabitEthernet0/0
      55.0.0.0/32 is subnetted, 1 subnets
O E2     55.55.55.55 [110/1] via 12.1.1.1, 00:06:43, GigabitEthernet0/0
      57.0.0.0/24 is subnetted, 1 subnets
O        57.1.1.0 [110/3] via 12.1.1.1, 00:06:43, GigabitEthernet0/0
O     192.168.3.0/24 [110/4] via 12.1.1.1, 00:06:43, GigabitEthernet0/0

iosv-7#sh ip ro ospf | b Gate
Gateway of last resort is not set

O     2.0.0.0/8 [110/4] via 57.1.1.5, 00:07:02, GigabitEthernet0/0
      11.0.0.0/32 is subnetted, 1 subnets
O E2     11.11.11.11 [110/1] via 57.1.1.5, 00:19:23, GigabitEthernet0/0
      12.0.0.0/24 is subnetted, 1 subnets
O        12.1.1.0 [110/3] via 57.1.1.5, 00:07:12, GigabitEthernet0/0
      55.0.0.0/32 is subnetted, 1 subnets
O E2     55.55.55.55 [110/1] via 57.1.1.5, 00:19:28, GigabitEthernet0/0
O     192.168.2.0/24 [110/4] via 57.1.1.5, 00:07:02, GigabitEthernet0/0

sham-link用にPEで作ったLoopbackがO E2としてCEに広告されてしまっている。

設定

iosv-1(config)#router ospf 100 vrf aaa
iosv-1(config-router)#summary-address 11.11.11.11 255.255.255.255 not-advertise
iosv-1(config-router)#summary-address 55.55.55.55 255.255.255.255 not-advertise 

iosv-5(config)#router ospf 100 vrf aaa
iosv-5(config-router)#summary-address 11.11.11.11 255.255.255.255 not-advertise
iosv-5(config-router)#summary-address 55.55.55.55 255.255.255.255 not-advertise 

After

iosv-2#sh ip route ospf | b Gate
Gateway of last resort is not set

      57.0.0.0/24 is subnetted, 1 subnets
O        57.1.1.0 [110/3] via 12.1.1.1, 00:09:37, GigabitEthernet0/0
O     192.168.3.0/24 [110/4] via 12.1.1.1, 00:09:37, GigabitEthernet0/0

iosv-7#sh ip ro ospf | b Gate
Gateway of last resort is not set

O     2.0.0.0/8 [110/4] via 57.1.1.5, 00:11:03, GigabitEthernet0/0
      12.0.0.0/24 is subnetted, 1 subnets
O        12.1.1.0 [110/3] via 57.1.1.5, 00:11:13, GigabitEthernet0/0
O     192.168.2.0/24 [110/4] via 57.1.1.5, 00:11:03, GigabitEthernet0/0

sham-link用のLoopbackがCEに広告されなくなった。

ping check

inserthostname-here:~$ ping 192.168.3.1
PING 192.168.3.1 (192.168.3.1): 56 data bytes
64 bytes from 192.168.3.1: seq=0 ttl=42 time=12.872 ms
64 bytes from 192.168.3.1: seq=1 ttl=42 time=10.492 ms
64 bytes from 192.168.3.1: seq=2 ttl=42 time=11.638 ms
^C
--- 192.168.3.1 ping statistics ---
3 packets transmitted, 3 packets received, 0% packet loss
round-trip min/avg/max = 10.492/11.667/12.872 ms
inserthostname-here:~$ traceroute 192.168.3.1
traceroute to 192.168.3.1 (192.168.3.1), 30 hops max, 46 byte packets
 1  192.168.2.254 (192.168.2.254)  2.388 ms  2.926 ms  2.786 ms
 2  12.1.1.1 (12.1.1.1)  3.560 ms  3.118 ms  5.984 ms
 3  13.1.1.3 (13.1.1.3)  15.605 ms  11.071 ms  12.046 ms
 4  34.1.1.4 (34.1.1.4)  13.168 ms  11.345 ms  23.358 ms
 5  57.1.1.5 (57.1.1.5)  12.306 ms  12.568 ms  12.513 ms
 6  57.1.1.7 (57.1.1.7)  19.690 ms  12.774 ms  14.329 ms
 7  192.168.3.1 (192.168.3.1)  15.537 ms  11.506 ms  14.185 ms

問題なし。

参考

CCIE Enterprise Infrastructure Foundation, 2nd Edition