VPC - M1 & F2E modules - BIG ISSUE !!!

[Rajagopal Sivaramakrishnan]

Hi All

We were planning to move our existing M132 modules and replace it with F248-E modules. As of now, M132's take all downlinks to N5K (trunks - L2 only) . F2E will be in a VDC where we have other modules like M1/M2. We are testing this, and everything worked as expected , except :

1) After migrating to F248-E module on N7K1 - we reconfigured the peer link , and layer 2 links to N5k , and BOOOOM - the whole datacenter LAN segment reachability went down. This was probably because N5K was connected to AGGR1 on F2E module, and to AGGR2 on M132 module. It threw an error - " LOCAL CARD TYPE DOESNT MATCH WITH PEERS" and suspended all downlinks to N5K.

After we migrated the 2nd N7K also to F2E module - the problem was solved, but during the transit state - all the N5K segments lost L2 connectivity.

Is there a better way to do this upgrade ? Thanks to god - that this was a lab network.. If this was production, we would have lost access to all the servers in the datacenter.

Pleaseeeee help if there is a work around for this problem.

[Rajagopal Sivaramakrishnan]

We got a workaround for this problem 

We will try it today and ill let you know if it solved this issue.

[InayathUlla Sharieff]

Raja,

• The vPC peer-link interfaces must be on the same module type on both vPC peers as described in the vPC Peer Link and I/O Modules Support In Cisco NX-OS Release 6.2 section of the Cisco Nexus 7000 Series NX-OS Interfaces Configuration Guide, Release 6.x.
  
  For instance, a vPC peer-link made of M1 interfaces on one side and of F2 interfaces on the other side is not supported. The peer-link should consist of either M1-only ports, F1-only ports, or F2-only ports on both vPC peer switches.
   
• If the current N7k chassis does not have enough empty slots to host all the required F2 modules, a new chassis is needed for the migration procedure for each fully-loaded switch that already exists.

Ref:

http://www.cisco.com/c/en/us/support/docs/switches/nexus-7000-series-switches/116424-technote-vpc-00.html

HTH

Regards

Inayath

*********Plz dont forget to rate the post if this is helpfull.

[Nuno Marques]

Hi,

for migration proposes can we have the following topology:

N7K-1     VPC Peer link    N7K-2
M2    -----------------------  M2
M1    ----------------------   M1

this would allow us to migrate the peer-link from M1 to M2 cards.

thanks in advance.

[InayathUlla Sharieff]

yes ofcourse you can use it.

[Nuno Marques]

Hi insharie,

on ly problem is that cisco docs mencion that u cannot have a PO with M1 and M2 2 members..

right?

thx in advance

[Rajagopal Sivaramakrishnan]

We solved this issue with the workaround solution.. it was kinda a long process, but it worked.

Solution was:

1) existing VPC was connected to M1 modules as given in the issue

2) we had to build a new vPC/port channel and connect it from N5K to F modules

3) Since there are 2 port channels now, spanning tree kicks in, and blocks the 2nd port channel connected to F module

4) Then we shutdown the port channel which was connnected to M module. Because of STP reconvergence we lost 1 packet (which is better than losing the whole zone)

5) We can then move the ports on M module to F, and add it to the new port channel

6) then shutoff the temporary links which we added in Step 2.

This solution works great.

Thanks for all help :)

Raj