OTV for 1km distance between data centers

[Jeremy Dubrulle]

Hi, I'm working on a data center new design. We have two equivalent DCs with 1km fiber between them. I've studied what is OTV but I'm not sure if OTV can be used for DCs with 1 km between them. I mean is it alright, without OTV, to design one Nexus 5k on each site doing vPC with FEX on each site? OTV is just for WAN interconnection, not MAN?

Thanks,

[Menelaos Sazos · Accepted solution]

Hello!

1km is totally not a distance for a dark-fiber DCI. You don't need an overlay like OTV, better use just regular L2 links as if they were between neighbouring racks. Also, N5K is not capable of the OTV.

I would rather recommend you to have a pair of N5Ks on each site as L2-only devices and a distributed pair (e.g. one device on each site) of N5Ks or N7Ks on top of it with L3 feature-set.

[Jeremy Dubrulle]

Thank you for the help.

Ok I agree with your design (with fabricpath), but for restricted budget, one N5K on each site, with FEX (with vPC) and fex-adapters, vm-fex, is a good design too?

[Menelaos Sazos]

For the technologies - yes, but from the redundancy standpoint - probably not, because if only one of the N5Ks is lost (maybe, due to the software upgrade), whole site is lost.

[Jeremy Dubrulle]

No because there will be vPC between each FEX and both N5K. So all FEX will be connected with redundancy to the two N5K

[Menelaos Sazos]

In such a case, you're good to go, if the fiber capacity is enough between the sites.

[Jeremy Dubrulle]

Ok thank you very much for the help!