Fabric Interconnect uplink port to nexus network outage

[mehulgajjar]

Dear all,

need your help to troubleshoot.

when i am trying to configure up link port towards to nexus switches ( which is connect to Netapp), existing network get fluctuate and cant configure up link port.

an attaching network diagram for ref.

any suggestion or best practice while add new uplink port to nexus switches.

at switches side, trunk port configured and all VLAN passing while i check sh run int ethernet 1/25.

[Kirk J]

I am assuming your FIs are operating in the recommended and default 'End Host Mode'?

If so, there should be no FI<>FI connectivity other than the L1/L2 cable for heartbeat/sync.

Also, your FI uplink ports should be configured as spanning-tree port type edge on the upstream NXOS devices.

If you have flapping ports, then you may have a bad SFP or cable somewhere.  As the FIs are in cut through mode, you could have and upstream or downstream source of bad frames, etc.

You will need to see what is logged as to the reason for the port flaps.

Kirk...

[mehulgajjar]

Thanks for reply.

Yes. FIs are working in cluster and in End host mode only. I have been checked port status during the troublshoot. its was up.

no port flapping issue here. when i try to create uplink, existing network get disconnected.

however spanning-tree port type edge i didn't checked this.

do you have any other recommendation.

[Kirk J]

So you are talking about your existing UCSM logical networking networking connectivity 'flapping' going down?

If you are adding additional links to the UCSM intended for different vlans, then you are configuring a disjoint layer 2 network, and will need to prune the require vlans off of each of the sets of uplinks, so that only the intended vlans are configured per uplinks.

Please see: https://www.cisco.com/c/en/us/solutions/collateral/data-center-virtualization/unified-computing/white_paper_c11-692008.html

Thanks,

Kirk...

[mehulgajjar]

Hello,

I have contacted to Cisco TAC and he suggest for configure network disjoint layer 2 at UCS level as configure uplink will conficts VLANs.

will update on this.