vPC and LAG Convergence

vPC and LAG Convergence

Thursday November 16, 2017

 

Recently Cisco released NXOS 7.0(3)I7(1) for the Nexus 9000 series switches. This brings two new features, called vPC Fast Convergence and LACP Convergence. These are also available on the 7000 series switches.

There wasn’t a lot of information readily available, so I’m going to share what I’ve learned here. I’d like to take a moment to thank Amith Ronad from Cisco for helping me to understand these features.

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Hitless vPC Role Change

Hitless vPC Role Change

Thursday October 19, 2017

 

“Always two there are; no more, no less. A vPC primary and a vPC secondary.”Yoda (paraphrased)

 

Like Yoda says, there has always been a primary and secondary in a vPC relationship. But, they’ve always been non-preemptive. That means that a secondary will not automatically become primary unless there’s a failure of some sort.

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Dynamic Routing and FEX

Dynamic Routing and Fabric Extenders

Wednesday August 30, 2017

 

The Problem

A few weeks ago I was working on a customer’s network when I found an OSPF problem. For some reason, an ASA wouldn’t peer with a Nexus switch. To make it a bit weirder, the problem only happened on the default VRF, and only with OSPFv3. On the Nexus side, I could see the ASA neighbour, but it was stuck in INIT. On the ASA side, I couldn’t see the neighbour at all.

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