Question about Router IDs and multiple L3outs

[brlehigh]

Hello all,
I have a typical network-centric fabric design.  I have a need to create several L3Outs between ACI and a pair of ASAs (multiple contexts).  Even though we will only be doing static routing across these L3Outs, it appears I am still required to assign a router ID to each border leaf for each L3Out.
Since we will only be doing static routing over these L3Outs is there a reason that I can't or shouldn't reuse the same router IDs?
Happy to provide additional detail if needed.
Thanks.

[Sergiu.Daniluk · Accepted solution]

If the L3Outs are in the same VRF, as far as I remember, you will get a fault if you try to reuse the same router ID on different Leafs.

Also, the RID is per-VRF, meaning if you have multiple L3Outs on the same Leaf, you must use the same router ID in all L3Outs.

Take care,

Sergiu

[brlehigh]

Thank you, @Sergiu.Daniluk .  Helpful as always.
Follow-up question for clarification.  You said that the RID is per leaf, per VRF.  So, if I have 5x L3Outs within the same VRF, I would use the same RID on the leaf for each of the 5 L3Out.  This makes sense.
Let's say that each of those L3Outs in separate VRFs.  Am I able use the same RID for each of the L3Outs in this scenario?  If yes, is there any reason not to do this?
Thanks! 

[Sergiu.Daniluk]

Yes, you should be able to use the same RID in different VRFs on the same leafs. There are situations where you don't want to do it. For example a VRF sandwich design, where you have neighborship adjacency from your two VRFs with a FW that has only one VRF. In that situation, you will probably have issues with bringing up the adjacencies. In your case with static routing it should be ok, I don't see a problem.

Regards,

Sergiu

[prasanth_k]

Hi Sergiu,

Do you know how to create multiple l3outs in the same vrf using postman ?

It is complaining about the same router id being using and i cant push the script without RID. 

If I create the l3out manually using GUI the router ID automatically pop up so its not an issue but using API it is complaining about Router ID

Any ideas ?