[Originally posted May 1, 2012 10:48 AM by Antti Uitto [ updated May 3, 2012 2:29 PM ]]
Part II OSPF as IGP
Let’s take a look at the IPv6 routing table.
show ipv6 route
You will see only addresses that are connected directly to that router. So if you are at R1, you will see 2001:99:13:4a::1/128 plus the link-local addresses of each interface on R1.
If you would try to ping R2 with address 2001:99:13:4a::2 it will not respond to you. The reason for this is that since there are no routes, R1 does not know where to send traffic that is supposed to go to 2001:99:13:4a::2 and even if it did, R2 does not know how to return packets.
In the next episode we will add BGP to this network and the BGP adjacencies will be created using lab router’s loopback addresses. Since the loopbacks are now unreachable, this would not work.
Now you could write static route and thus tell R1 from where to find the address 2001:99:13:4a::2 but that would spoil the whole thing. We are trying to make a network that has a dynamic routing.
So we want to add an IGP.
The job of the Interior Gateway Protocol is to make sure that the core nodes of this network will find each other at all times. They need to find each other’s loopback addresses.
My choise for IGP in this lab is OSPF.
Here are the spells to get it going.
set protocols ospfv3 area 0.0.0.0 interface eth0.12
set protocols ospfv3 area 0.0.0.0 interface eth0.13
set protocols ospfv3 area 0.0.0.0 interface eth0.14
set protocols ospfv3 area 0.0.0.0 interface eth1
set protocols ospfv3 area 0.0.0.0 interface eth2
set protocols ospfv3 area 0.0.0.0 interface lo
set protocols ospfv3 parameters router-id 10.5.5.1
Please adjust the interfaces to suit your configuration.
You will want to add every interface that points to other routers in your core. Do not forget to add loopback as well. Give each router an id. This id is typically the the same as the IPv4 loopback address of your router.
Now check IPv6 routing table again.
show ipv6 route
You should see the loopbacks of all lab routers.
sudo ping6 2001:99:13:4a::8 -I 2001:99:13:4a::1
show ipv6 route ospf6
show ipv6 ospfv3
show ipv6 ospfv3 neighbor
show ipv6 ospfv3 neighbor detail
show ipv6 ospfv3 route
show ipv6 ospfv3 route detail
show ipv6 ospfv3 interface eth0.12
show ipv6 ospfv3 database
show ipv6 ospfv3 area