IPv6 Addressing with OSPFv3

By Wendell November 17, 2015 09:05

For this latest lab, you configure IPv6 routing, addressing, and OSPFv3, all in one small lab. This next lab is rather long by comparison to most others in this series – it might take you 10-15 minutes rather than the usual 5-10. Of particular note: the WAN links between routers do not use global unicast addresses. Details below the fold!


Configure IPv6 addressing and OSPFv3 in a small IPv6 network. In this case, the IPv6 addressing configuration uses a small twist: the links between the routers use only link local addresses. You will need to enable IPv6 routing, configure unicast IPv6 addresses on some interfaces, enable IPv6 on the WAN interfaces, and then add OSPFv3 to the configuration.

The specific rules for this lab are:

  • Configure the IPv6 addresses needed on all the routers per the figure.
  • On all three router’s G0/3 interfaces, configure the IPv6 address/mask shown in the figure.
  • On all three router’s G0/1 and G0/2 interfaces (the links between routers), use only Link-Local addresses
  • Explicitly configure (that is, do not rely on interface IP addresses) the OSPFv3 router-ID (RID) using the template x.x.x.x, where x is the router number
  • Use OSPF area 0
  • Use OSPF process-ID 50 on all routers
  • Configure nothing else that is not needed based on the requirements listed here

Figure 1: Three Router Triangle without Unicast IPv6 Addresses


Initial Configuration

Example 1, 2 and 3 show the relevant beginning configuration state of R1, R2 and R3.

Example 1: R1 Config

Example 2: R2 Config

Example 3: R3 Config



Answer on Paper, or Maybe Test in Lab

Create your own answer, either by typing it in somewhere, or writing it on paper. Try to avoid using your notes – one of points of these labs is to move you from being able to read someone else’s config to being able to create your own from scratch.

You can easily test this lab with a few show commands. First, each router should have two OSPFv3 neighbors (show ipv6 ospf neighbor). Each router show list two OSPF-learned IPv6 routes (show ipv6 route), basically one for each of the two remote IPv6 prefixes shown in the figure. You can check the interface IPv6 addresses with show ipv6 interface, and the OSPF router ID with show ipv6 ospf database.


Do this Lab with Cisco’s VIRL

You can do these labs on paper and still get a lot out of the lab. As an extra help, we have added files for the Virtual Internet Routing Lab (VIRL) software as well. The .VIRL file found here is a file that when used with VIRL will load a lab topology similar to this lab’s topology, with the initial configuration shown in the lab as well. This section lists any differences between the lab exercise and the .VIRL file’s topology and configuration.

Download this lab’s VIRL file!

Network Device Info

The .VIRL topology matches this lab topology exactly. The host info does as well.

Host Device Info

This table lists host information pre-configured in VIRL, information that might not be required by the lab but may be useful to you.

Device IP Address Mac Address User/password
PC1 2001:DB8:1:1::100/64 02:00:11:11:11:11 cisco/cisco
PC2 2001:DB8:2:2::100/64 02:00:22:22:22:22 cisco/cisco
PC3 2001:DB8:3:3::100/64 02:00:33:33:33:33 cisco/cisco

Handy Host Commands

To see PC IP address: ifconfig eth1

Ping example: ping6 -c 4 2001:DB8:1:1::100

Trace example: tracepath6 2001:DB8:1:1::100


Answers: IPv6 Addressing with OSPFv3
Answers: Trunking for Only Some VLANs
By Wendell November 17, 2015 09:05
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  1. Mike November 17, 21:05

    More v6 fun! 😉

    ! substitute x for the router number,
    ! otherwise the config is identical for all 3 routers
    ipv6 unicast-routing
    ipv6 router ospf 50
    router-id x.x.x.x
    int gi0/3
    ipv6 address 2001:db8:x:x::1/64
    int ra gi0/1 – 3
    ipv6 enable
    ipv6 ospf 50 area 0

    Reply to this comment
  2. Gabriel Moran November 26, 17:27

    The lab doesn’t give enough info regarding g0/3 interfaces, it does not state to use eui-64 rules or to explicitly set the interface to ::1, ::2, ::3, etc.

    Reply to this comment
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