Task 3.2 VRF Question

So I'm confused on this...

When you enter vrf definiton from global config to create a VRF, why are you required to enter address-family ipv6 mode if you already ran the command vrf definition to begin with?  I was under the impression that the difference between ip vrf and vrf definition was IPV4 and IPV6 respectively?

Also, what is the purpose of the below if you already said vrf definition <name> to begin with?

address-family ipv4
address-family ipv6

Thanks all!


  • The legacy "ip vrf XXX" mechanism only supported IPv4 - you did not need to specify which address family it was for due to this reason. The newer VRF syntax allows you to select which address family you want to use it for - by default no address families are activated. If the interface is running v6, and you need that v6 link to belong to a vrf, then you need to ensure that the vrf has the address family activated. 

    You will get errors such as these if the address family is not first activated: 


    vrf definition TEST


    interface loop 100

    ip add

    %Loopback100 is linked to a VRF. Enable IPv4 on that VRF first.


    ipv6 add 2001::/128

    %Loopback100 is linked to a VRF. Enable IPv6 on that VRF first.


    Hope this helps

  • I think I get it now.  Specify af within the vrf to prepare it for ipv4 and or ipv6 or it won't work.  I was thrown off by the immediate exit family after each af within the vrf but now I understand.  Thanks!

Sign In or Register to comment.