Hello Bart,
Normally I request the platforms and server teams to change LACP timers to the preferred NXOS of normal. Please bare this in mind! I am guessing that the servers or blade chassis have themselves negotiated at fast. By default NXOS is normal to my recollection. HP7000s needed some sort of upgrade to be able to select normal mode.
I think the re-negotiation of LACP might just be a blip but dependency on the server side if it will accept it if you hard coded on nxos side. Depending on what needs to happen to the line cards during and after the ISSU obviously not sorting timers could lead to decent down time.
Obviously works to be carried out of business hours if there is such a thing in your environment.
hth
Bilal
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