Cisco Nexus 9k Hardware Migration C9372PX to C93180YC-EX

[Andrew Klinke]

Hello,

I am planning to replace a pair of Nexus switches model C9372PX with a pair of C93180YC-EX

We have them deployed in a vPC domain each has a number of FEX modules, all of which are model N2K-C2348TQ-10GE. We do not plan to change the FEX modules.

All of the connections we care about come in via a vPC and its for a hospital which operates 24/7 so are investigating to see if we can upgrade without downtime to our vPC's.

I can't find a guide on such a migration or get a definitive answer on whether the vPC domain & connections will form between the different models of switches. Clearly this is key to whether we can perform a migration without impact.

I wondered if anyone else has tried such an upgrade and if so did you manage to get the vPCs to form across the switches & downtime-less cut-over?

Any advice, tips and tricks for this upgrade will be appreciated.

Thanks

Andy

[marce1000]

 - Hm, for such vital operations, good replies may bee receive here , but you must also consider if they can be authoritative , for such cases I would work with a re-seller to get the necessary know-how.

 M.

[Andrew Klinke]

Hello Marce1000,

We are working with our support partner and Cisco TAC on this however I would also like to open it up to the community as good though TAC are, there experience seems to be routed in the lab and not the real world. I think there is more experience out there in the world and what better forum to tap into it than this community!

Thanks for your response though.

Regards

Andy

[Alfred Swarts]

Hi Andy,

Did you managed to get any information as I am also doing what you have done

Thanks 

Alfred

[Andrew Klinke]

Hello,

We had a few calls with TAC of which the outcome was that a no-downtime cutover wasn't possible as the old and new 9k's have incompatible asics so can not form a vPC domain.

In the end we tackled the change like this:

1. Bench-set up the new Nexus 9k's, Confirm the vPC link forms and that you (DO NOT USE THE SAME VPC DOMAIN AS THE ORIGIONAL SWITCHES)
2. Rack the new 9k's alongside the old
3. Disconnect one of the FEX modules (disconnect all edge ports also) and move across to the new 9k
4. Configure the FEX's ports
5. Move the FEX's edge devices one at a time by disconnecting the remaining po link to the old switch then reconnecting to the new
6. Repeat until all FEX's are moved over

So this process involves disconnecting one leg of each port channel, then disconnecting it completely, connecting one leg to the new switch then following up with reconnecting the 2nd leg and regaining resilience.

We did this with the migrations taking place over the course of a week. The majority of connections were VMWare hosts, storage, firewalls, and servers.

We were lucky in that all the critical stuff was connected via vPC. By having 2 people disconnect and reconnect at the same time the connectivity loss was minimal (20 seconds in the worst case) and didn't have any knock-on effects with our systems i.e. were in tolerance for our applications.

Hope this helps

Andy

[networker9]

I have a similar migration requirement..
from c9396px with 2 FEX (2248T , 2232P) to be migrated to new "N9K-C93240YC-FX2".

Not replacing the FEX for now as it shows supported to the new model as well.

Couldn't find a document that i could say as helpful till now.