Nexus 5548 VPC to 3850 Ether channel

[jamaludeen_s]

Hi,

I've got the following problem, I configured two nexus 5548 UP in one vpc domain. I am trying to make VPC (One port on each switch Port eth 1/8) to C3850. other side the two ports are configured for ether channel. I could see that only one port in the port channel is active and the other one is in suspended state.

I disables udld, wthe moment i enable udls on nexus all the ports are going down stating UDLD Echo

Attached configuration. Please check 

Regards

Jamal

[Reza Sharifi]

Hi,

Looking at your config po131 is not in a vpc.

try adding

int po131

vpc 131

to both 5ks and test again.

HTH
 

[jamaludeen_s]

Hi Reza,

I tried vpc 131 under port-channel 131, still i had the same problem.

sh vpc shows that the vpc 131 is down

[gfogleman1]

If you type show vpc peer-keepalive does it say success for everything?

Also

"vPC Peer-Switch Since NX-OS 4.2(6), 5.0(2a) and further, an enhancement, called vPC peer-switch, was brought to STP in the context of vPC. The vPC Peer-Switch feature (Figure 42) allows a pair of vPC peer devices to appear as a single Spanning Tree Protocol root in the Layer 2 topology (they have the same bridge ID). vPC peer-switch must be configured on both vPC peer devices to become operational. The command is the following: N7K(config-vpc-domain)# peer-switch"

.

and you will need

"int po131

vpc 131"

Ref:http://www.cisco.com/c/dam/en/us/td/docs/switches/datacenter/sw/design/vpc_design/vpc_best_practices_design_guide.pdf