IPv6: Route filtering in OSPFv3:

IPv6: Route filtering in OSPFv3:

·         Let me configure OSPFv3 between 2 routers

R1----fa0/0-------------------fa0/0-----R2

2001:12::1----------------------2001:12::2

 

·         R1’s Loopback0: 2001:1::1

·         R2’s loopback0: 2001:2::2

·         R2’s loopback1: 2001:22::22

R1(config)#ipv6 router ospf 1

R1(config-rtr)#router-id 1.1.1.1

R1(config-rtr)#

R1(config-rtr)#int fa0/0

R1(config-if)#ipv6 ospf 1 area 0

R1(config-if)#int loop0

R1(config-if)#ipv6 ospf 1 area 0

R1(config-if)#

 

R2(config)#ipv6 router ospf 1

R2(config-rtr)#router-id 2.2.2.2

R2(config-rtr)#int fa0/0

R2(config-if)#ipv6 ospf 1 area 0

R2(config-if)#int loop0

R2(config-if)#ipv6 ospf 1 area 0

R2(config-if)#

R2(config)#int loop1

R2(config-if)#ipv6 ospf 1 area 0

R2(config-if)#

 

R1(config)#do show ipv6 route

IPv6 Routing Table - 8 entries

Codes: C - Connected, L - Local, S - Static, R - RIP, B - BGP

       U - Per-user Static route

       I1 - ISIS L1, I2 - ISIS L2, IA - ISIS interarea, IS - ISIS summary

       O - OSPF intra, OI - OSPF inter, OE1 - OSPF ext 1, OE2 - OSPF ext 2

       ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2

C   2001:1::/64 [0/0]

     via ::, Loopback0

L   2001:1::1/128 [0/0]

     via ::, Loopback0

O   2001:2::2/128 [110/10]

     via FE80::C001:25FF:FE30:0, FastEthernet0/0

C   2001:12::/64 [0/0]

     via ::, FastEthernet0/0

L   2001:12::1/128 [0/0]

     via ::, FastEthernet0/0

O   2001:22::22/128 [110/10]

     via FE80::C001:25FF:FE30:0, FastEthernet0/0

L   FE80::/10 [0/0]

     via ::, Null0

L   FF00::/8 [0/0]

     via ::, Null0

R1(config)#

 

R2(config-rtr)#do show ipv6 route

IPv6 Routing Table - 9 entries

Codes: C - Connected, L - Local, S - Static, R - RIP, B - BGP

       U - Per-user Static route

       I1 - ISIS L1, I2 - ISIS L2, IA - ISIS interarea, IS - ISIS summary

       O - OSPF intra, OI - OSPF inter, OE1 - OSPF ext 1, OE2 - OSPF ext 2

       ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2

O   2001:1::1/128 [110/10]

     via FE80::C000:25FF:FE30:0, FastEthernet0/0

C   2001:2::/64 [0/0]

     via ::, Loopback0

L   2001:2::2/128 [0/0]

     via ::, Loopback0

C   2001:12::/64 [0/0]

     via ::, FastEthernet0/0

L   2001:12::2/128 [0/0]

     via ::, FastEthernet0/0

C   2001:22::/64 [0/0]

     via ::, Loopback1

L   2001:22::22/128 [0/0]

     via ::, Loopback1

L   FE80::/10 [0/0]

     via ::, Null0

L   FF00::/8 [0/0]

     via ::, Null0

R2(config-rtr)#

 

Observation:

·         OSPF has been configured between R1 and R2

·         R1 has advertised its loopback0 2001:1::1 into OSPF

·         R2 has advertised its loopback0 2001:2::2 into OSPF

·         R2 also advertised its loopback1 2001:22::2 into OSPF

·         Now, let me filter the route 2001:2::2 from R1

R1(config-rtr)#distribute-list prefix-list LOOP-R2 in fastEthernet 0/0

R1(config-rtr)# ipv6 prefix-list LOOP-R2 seq 5 deny  2001:2::2/128

R1(config)# ipv6 prefix-list LOOP-R2 seq 10 permit ::/0 le 128

·         Now, let me check the routing table in R1:

R1(config)#do show ipv6 route

IPv6 Routing Table - 7 entries

Codes: C - Connected, L - Local, S - Static, R - RIP, B - BGP

       U - Per-user Static route

       I1 - ISIS L1, I2 - ISIS L2, IA - ISIS interarea, IS - ISIS summary

       O - OSPF intra, OI - OSPF inter, OE1 - OSPF ext 1, OE2 - OSPF ext 2

       ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2

C   2001:1::/64 [0/0]

     via ::, Loopback0

L   2001:1::1/128 [0/0]

     via ::, Loopback0

C   2001:12::/64 [0/0]

     via ::, FastEthernet0/0

L   2001:12::1/128 [0/0]

     via ::, FastEthernet0/0

O   2001:22::22/128 [110/10]

     via FE80::C001:25FF:FE30:0, FastEthernet0/0

L   FE80::/10 [0/0]

     via ::, Null0

L   FF00::/8 [0/0]

     via ::, Null0

R1(config)#

 

Observation:

·         2001:2::2 route is not there in the R1’s routing table