Nexus 9k to Dell connectivity create mac flapping issue

[sarpareashish]

Trying to connect my 2 L3 Nexus 9332 switches to 2 Dell 4148 switches with VPC on nexus and normal port channel on Dell. These Dell 4148 switches are connected to 2 Dell 5248 switches with VLT port channel on 4148 and normal port channel on 5248 in downstream.

Both Dell4148 are also connected to all my DMZ switches with VLT on dell and normal port channel DMZ switches. I have total 4 DMZ networks in which there are 2 switches connected with trunk port to reach other.

Issue is when we reboot one of the dell switch then we start facing mac flapping issue on nexus and DMZ switches. We start learning our existing servers MAC addresses from the dell switches. Dell switches has no connectivity with our existing servers.

We have confirmed our configuration from Cisco TAC. No issue on cisco configuration. Please help me to find out issue.

[Oleg Volkov]

Hello!

what LAG protocol you use?

static or LACP?

can you show part of configuration Nexus and Dell? 

[sarpareashish]

Yes. We are using LACP. Port-channel is not the issue. we were getting mac flapping on single interface as well. Now it has been resolved but we get same issue when any switch is rebooted.

We suspect dell switch is not behaving properly with nexus and putting its all interface in forwarding mode when its rebooted.

Please suggest.

[balaji.bandi]

It should be straight foward configuration from dell point of view :

https://www.dell.com/support/article/uk/en/ukdhs1/how10364/how-to-create-link-aggregation-groups-lags-on-dell-networking-powerconnect-switches?lang=en

Still have issue, can you post more configuration on the both the side and and also 

show vpc

show port-channel suammry

show run inter por-channel XX

same also from DELL side as per the document.

[sarpareashish]

Do you mean dell switches doesn't support criss cross connectivity with Nexus?

We have tried straight connectivity as well. Straight port channels with Dell from nexus but still facing issue.

Same happening with my DMZ switches. When dell switch is rebooted then it creates mac flapping in all my connected switches.

Config of Dell connected port-channel on both Nexus:

Interface port-channel 50

switchport

switchport mode trunk

switchport trunk allowed vlan xyz

spanning-tree port type normal

vpc 50