Traffic Lose while Nexus 5000 non ISSU Upgrade

[radwango1]

Hi,

we have 2* 5672 each of them connected to 2* 2348 cisco the two 5672 form a vPC domain

the devices connected to the FEx are configured as static port channel, the connected port on the fex devices configured as vPC

While upgrading from 7.2 1 N1 to 7.3 1 N1 the devices on static port channel suffer from loss in traffic

As I know, disruptive ISSU upgrade should be possible without traffic interruption to the attached systems, as long as all attached via vPC and only one vPC peer is upgraded at a time

can someone help me to know why the non ISSU upgrade cause a traffic interruption instead of being vPC ?

[nazimkha]

Hi,

Minimal traffic loss is expected if the switches are upgraded in non-ISSU mode.

However a major outage while upgrading is caused as the vPC pair was not upgraded in a certain order of operations.

Though the vPC switches are 2 physical switches with different control planes but they are tied together to look like a single switch to the port-channeling network element.

It is very important to know the vPC switch roles and failure scenarios before planning for a non-ISSU upgrade to keep the traffic interruption at the minimum.

Regards,

Nazim