N7K OTV with 2 different providers

[Caue W]

Hi,

I'm no DC expert, need some guidance.

We're currently connecting 2 small DC's using Cisco N7K with OTV running to extend the VLANs. They're connected using 1 link from 1 provider (1 Gbps layer 2 link with jumbo frame). Customer wants to add a second link from a different provider, it'll be also a Layer 2 with jumbo frame (specifications as per the first link).

When the DC was implemented with the first link, the responsible engineer said it was impossible to add a second one to work with OTV & so on...

Is there any restrictions to add a second link? If so, there's any design guide, config guide specifically pointing that out and the restrictions that comes with the technology?

Thanks for the assistance!

[Sergiu.Daniluk]

Hi @Caue W 

It's not clear if the provider link is directly connected to OTV VDC. In other words, is the join interface the link to provider or is going to your core router and from there to DCI?

If is going to between core routers, then you don't have to worry, in the end is just a routed network. It can be as you wish.

If is going directly to OTV VDC, then most likely your current configured join interface is a layer 3 physical port. If you want to add a new provider, then you must change the config and use a loopback as your join interface. Something like that: 

This feature was not from the beginning of OTV. So yeah, depending on when OTV was implemented in your network, then it might not have been supported at that time.

EDIT: if you plan on using loopbacks as join interface, make sure you configure a secondary IP for depolarization.  If you have two edge devices in an overlay network, then each edge device is configured with two IP addresses.

Take care,

Sergiu