Hairpin OTV & LISP traffic?

[ryan.lambert]

Hi,

Does anyone know if this is a functional configuration? For instance:

I've got 3 sites -

Site 1 is connected to Site 2.

Site 3 is connected to Site 2.

Site 1 & Site 3 have no connectivity between each other, but want to extend Layer 2 via OTV and mobility Layer 3 with LISP. Is it legitimate to somehow bridge OTV through site 2 to site 3 with a unicast adjacency server, as long as site 3's join interface is reachable to site 1 via IGP, and vice versa?

Would LISP be fine, assuming site 2 was a MS/MR and available to both at all times?

Thanks in advance!

[Harish Balakrishnan · Accepted solution]

Hello

Logically this is possible using OTV as long as their join interfaces are reachable each other. What type of connection do you have between Site 1 to Site 2 and Site 2 to Site 3.. Is it layer 2 or 3 ?

regards

Harish

[ryan.lambert]

Harish,

Thanks - it's all layer 2, so that would work. The only question I come up with now is, two of the sites are ASRs and one is a N7K. At the middle site (the one that both connect to), the ASR would be taking two separate handoffs for each different site. The only feasible way to get this to work would be to bring them in on a service instance in the same bridge-domain and make your join interface a BDI.

Also not sure if that is technically "supported". I know loopbacks on the ASR are not, so that's not much of an option.

I suppose the other option would be to bring both handoffs into a switch in front of the ASR, then hand the ASR one cable from it in the same VLAN.

Regarding the type of connection, it's about 500 meg... though the site that connects commonly is cold DR, so bandwidth utilization isn't too much of a concern other than the fact that having to hairpin through that site is a little bit suboptimal.