How to configure IPv6 OSPFv3 on Cisco IOS Router

When we use OSPF for IPv4 we are using OSPFv2. OSPF has been updated for IPv6 and is now called OSPFv3. These are two different routing protocols and in this lesson I’ll show you how to configure OSPFv3 so that you can route IPv6 traffic. Here’s the topology we’ll use:

Let’s start with the configuration of the interfaces and the IPv6 addresses. We don’t have to configure any global unicast IPv6 addresses on the FastEthernet interfaces because OSPFv3 uses link-local addresses for the neighbor adjacency and sending LSAs.

R1(config)#ipv6 unicast-routing 
R1(config)#interface loopback 0
R1(config-if)#ipv6 address 2001::1/128

R2(config)#ipv6 unicast-routing 
R2(config)#interface loopback 0
R2(config-if)#ipv6 address 2001::2/128

Don’t forget to enable IPv6 unicast routing otherwise no routing protocol will work for IPv6.

R1#show ipv6 interface brief 
FastEthernet0/0            [up/up]
Loopback0                  [up/up]
    FE80::CE09:18FF:FE0E:0
    2001::1

R2#show ipv6 interface brief 
FastEthernet0/0            [up/up]
Loopback0                  [up/up]
    FE80::CE0A:18FF:FE0E:0
    2001::2

After configuring the IPv6 addresses on the loopback interface you can see the global unicast and the link-local IPv6 addresses. There is no link-local address on the FastEthernet interfaces however so we’ll have to fix this:

R1(config)#interface fastEthernet 0/0
R1(config-if)#ipv6 enable

R2(config)#interface fastEthernet 0/0
R2(config-if)#ipv6 enable

R1#show ipv6 interface brief 
FastEthernet0/0            [up/up]
    FE80::CE09:18FF:FE0E:0
Loopback0                  [up/up]
    FE80::CE09:18FF:FE0E:0
    2001::1

R2#show ipv6 interface brief 
FastEthernet0/0            [up/up]
    FE80::CE0A:18FF:FE0E:0
Loopback0                  [up/up]
    FE80::CE0A:18FF:FE0E:0
    2001::2

Now we can configure OSPFv3:

Forum Replies

Hello Sanjiv.

In order to clarify why you’re getting the error, first let’s look back on how a router chooses its router ID. A router ID is always in the format of an IPv4 address. The router ID is chosen in the following order:

If a router ID is configured in the ospf configuration, this is used as the router ID.
If no router ID is configured, then it uses the highest IP address of a loopback interface
If no loopback interface exists, it will use the highest IP address of any physical interface in the “up” state.

Now if you’re using IPv4, then one of the a

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Hello Chris,

Good question, this can be confusing. Originally, OSPFv3 was created only for IPv6:

https://tools.ietf.org/html/rfc5340

Later, OSPFv3 was updated to support address-families:

https://trac.tools.ietf.org/html/rfc5838

This means you can run it for IPv6 and IPv4 (and some other address families like multicast).

The “ipv6 ospf” commands are the “old” commands and the “ospfv3” commands are the newer commands.

If you use “ipv6 ospf” on an interface and later use “ospfv3” then you’ll see that the “ipv6 ospf” command will disappear.

“ipv6 router ospf” is t

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something which is mentioned in other lessons but is still kind of cool to see is how OSPF uses the Link Local for all the management type data its sending…

Since I am studying for the Tshoot I am trying to lab up the majority of the topics that is covered for the exam. So I am building a ton of GNS3 labs.

I would say that really be familiar in how IPV6 OSPF is setup for example being able to identify if something was missing from the show running configuration could be paramount to passing.

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Hello Martha

When transitioning from IPv4 to IPv6 it’s necessary to reevaluate certain issues. It’s all part of the process! Remember that routing protocols in IPv6 use the link-local addresses to exchange information. The link-local address is automatically assigned to each IPv6 enabled interface and communication between connected IPv6 devices is automatically established using these addresses. For more info on the link-local address, take a look at this lesson:

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Hello Laz.
Thanks a lot

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