Issues with connectivity between HA PAs and Nexus Leaf Switches

rmeskill — Fri, 24 Jul 2026 14:32:35 GMT

I've inherited a setup which has PAs with two vsys each connecting:
external switch/router > PA external vsys > A10 Load Balancers > PA internal vsys > Cisco Nexus Leaf switches

We run a full mesh setup (1x interface from each side of the PA HA pair to each (upstream switch, external A10, internal A10) internal device, both primary and secondary side. Then on the inside from the Nexus leaf switches to the PA we run ae1 with 2 interfaces to each (pair) of leafs (1 & 2, 3 & 4).

I've been troubleshooting slow failover (2-5 minutes) between PAs but in trying to turn up HA Passive Link State: Auto (locally committed on my PAs) it took down the whole site. And I'm thinking there's some sort of configuration issue with the leaf connections to the PAs. To clarify:

On the leafs there are 2x unique VPCs (1 & 2, 3 & 4) and each pair of PA connections is on a port-channel for each of those VPC pairs (they're the same number, but physically/logically separate). Can anyone think of any reason this wouldn't work as is?

Re: Issues with connectivity between HA PAs and Nexus Leaf Switches

BPry — Fri, 24 Jul 2026 16:28:54 GMT

@rmeskill,

Did you review the logs on the Nexus and PAN side of things to see what they were doing during the outage? When you set the passive link state to Auto, did you also go into your AE interfaces and toggle the 'Enable in HA Passive State' under LACP?

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Issues with connectivity between HA PAs and Nexus Leaf Switches

Re: Issues with connectivity between HA PAs and Nexus Leaf Switches