RE: Nexus 5K vPC Peer link 1Gb over OM2 Fiber

On Thu, Apr 04, 2013 at 15:26:25, marc edwards wrote:
> Subject: Re: Nexus 5K vPC Peer link 1Gb over OM2 Fiber
>
> I would agree that vPC doesn't forward much data under normal
> circumstances... But what about forwarding mechanism in failure scenarios?
> If not addressing these during design, then one learns the hard way if
> the unfortunate situation happens. (ie switch failure down stream on
> chassis one causing forwarding only on chassis 2 but also a link
> failure on chassis two upstream to router)
>
> The whole concept of multi chassis solutions is to provide HA in
> failure scenarios which won't interrupt or cause severe limitations to
> data forwarding. If not setting up the vPC peer link for such
> scenarios, than why go with a multi chassis solution at all?
>

Planning for failures, that's crazy talk. The CCIE is all about designing stuff that doesn't make much sense. I've carried that into the real world :)

If you re-read what I wrote, I wasn't defending running it at 1G, I was just saying that under normal circumstances there should be little to no traffic across it. You have a design issue if there is. I also mentioned that I create mine using two links, a design recommendation. Offhand, I wasn't sure if it would form over 1G, but checked and found that it will throw an error.

I would venture to say that more problems come from Layer 3 VPC, than would arise from the choke of a 1G connection as a VPC peer link. Just throw a management port of a Netapp in the mix and watch the fun begin. I would like to see some of the limitations of the peer link relaxed if layer 3 is involved. After all, I'm burning 20Gbps worth of ports on both devices for a failure that might happen once in the next 5 years.

-ryan

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Received on Thu Apr 04 2013 - 19:45:37 ART