[c-nsp] Non-disruptive ISSU for Nexus 5000

[Tony Varriale]

On 3/14/2011 11:25 PM, Brad Hedlund (brhedlun) wrote:
> Hi Chuck,
>
> The switch not being upgraded will keep the vPC connections UP, just as you witnessed when your switch rebooted due to fan issues. However...
>
> Prior to the recent 5.0(2) release, IF your vPC connections were reset for some other reason (server rebooting) while you had one of your Nexus 5000s down for maintenance, your server vPC would not come back up. This is because the default behaviour is for the vPC primary switch to first check the vPC interface configuration is in sync with the secondary switch before allowing it come UP. If the secondary switch was down for maintenance you were SOL.
>
> In 5.0(2) a new "feature" was introduced called vPC Peer Config Check Bypass, which if configured, allows the vPC member ports to come UP even if the secondary switch is unavailable. The config check will happen after the secondary switch comes online, and if there is a mismatch only the new leg will be prevented while the existing leg continues to forward.
>
> Cheers,
>
> Brad Hedlund
> http://bradhedlund.com
> --
We waited a long time for this.  Previous to 5.0(2) it caused a lot of 
headaches.

tv