Concerning OTV and VLAN Assignments

[clayhawks]

I've been looking around but can't find any specific information...

When configuring OTV between data centers, is it required/advisable/best practice to have the VLANs that you need to extend from one DC to another have the same VLAN ID? Does that matter?

For example, VLAN 10 in New York DC is the 172.31.12.0/23 network. I want to extend the 172.31.12.0/23 network to the Los Angeles DC. Does the VLAN ID in the LA DC need to be VLAN 10 or can I use any VLAN ID in this case?

Thanks!

[Steve Fuller]

Hi Clay,

In my opinion it would be best practice to have the same VLAN numbering across the data centres you're extending VLANs, purely to keep things simple. Obviously if you translate from one VLAN number to another it will add some complexity and so complicate troubleshooting to some extent.

As far as whether having the same IP subnet assigned to different VLAN numbers is possible, I'm afraid you can't do this today. As of November 2012 Cisco were saying support for OTV VLAN translation would be available in the Nexus 7000 NX-OS 6.2 release. If you have Cisco Partner level access you can see the Nexus 7000 Roadmap Update presentation where this is discussed (see slide 11).

Regards