Configuration limits for OTV (Overlay Transp. Virtual.) on ASR1000

[jeanpauge]

Hello,

I would like to know what are the configuration limits for OTV on ASR1000 routers (*), something equivalent to that (Nexus7000):

https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus7000/sw/verified_scalability/cisco_nexus7000_verified_scalability_guide.html#reference_18192F87114B45D9A40A41A0DEF3F74D

*: ASR1002, ASR1001, ASR1001-X, all  under IOS XE Software, Version 03.16.08.S

A reference to a Cisco documentation welcome

[M02@rt37]

Hello @jeanpauge,

As I concerned, my ASR1001-X: The OTV scale is limited to 5000 MAC addresses and 1000 VLANs in total. There are no specific limits for the number of OTV adjacencies or sites. The recommended maximum MTU size is 1464 bytes. These limits are applicable for IOS XE Software version 3.15S and later.

The actual limits may vary depending on the specific hardware and software configurations of your ASR1000 routers.

[jeanpauge]

Hello,

Thanks for your reply which gives me interesting information.

Are the 5000 Mac adresses you mention the maximum OTV unicast routes the ASR1001-X can store, whatever these routes are locally learned (Via a bridge-domain) or advertised by other edges  (via IS-IS) ? And whatever the number of Overlay networks configured on the router ?

Thanks a lot.

[M02@rt37 · Accepted solution]

You're welcome @jeanpauge 

Yes, the 5000 MAC addresses I mentioned yesterday refer to the maximum number of OTV unicast routes that the ASR1001-X can store in its MAC address table. This limit applies to all types of OTV unicast routes, including locally learned routes via a bridge-domain, as well as routes advertised by other OTV edge devices via IS-IS.

It's important to note that this limit is a hardware limitation, which means that it applies regardless of the number of overlay networks configured on the router. In other words, the ASR1001-X can store up to 5000 OTV unicast routes in its MAC address table, regardless of whether those routes belong to a single overlay network or multiple overlay networks.

If your deployment requires support for more than 5000 OTV unicast routes, you may need to consider using a larger router model or implementing some form of route summarization or filtering to reduce the number of routes that need to be stored in the MAC address table.

[jeanpauge · Accepted solution]

Hello,

Your response is clear and useful.
I have already deployed OTV between 2 sites to transport 10 vlans: the main site (site A) with two OTV Adjacency servers running in the dual-site adjacency state, the other site (site B) with one OTV Edge device pointing the two OTV servers of the main site. A third site (site C) will come soon on the same overlay pointing the two adjacency servers of site A.

At present, on site B, I can see 

 (result of show otv overlay 1 route|mroute): 178 unicast routes displayed in Overlay1 and 69 multicast routes displayed in Overlay1

Apparently, far from the limit supported by the ASR1001-X.

I was just wondering about the AED (Authoritative Edge Device) role hold by the two OTV adjacency servers in the main site resulting in the fact that the odd vlans are hold by one Edge, the even vlans by the other edge. Is there a way to control that repartition, I mean saying explicitly that vlanX should be hold by a specific Edge, and taken in account in the negociationafter between  the two Edge. I realize that this is a new question not related to the original one.

Best regards.