Maximum number of Port members on a Port-channel with Nexus 5K with Fex

[Fernando Hernández]

Hello Guys.

Is there a limit of active port members on a Port-channel using Cisco Nexus 5K with FEX (Nexus 2K)?

I have 2 Switches Nexus 5K on VPC and both of them have 2 FEX attached.
The thing is that there is a need of connecting a Switch from another vendor and they use TenGig interfaces. There are no other Switches in the Data Center that have TenGig interfaces, unfortunately, but only the Nexus 2K. Plus they are not fibre interfaces but UTP/cobber.
When I configure the Port-channel only 4 interfaces come up from the 8 ports in the port-channel (the first 4 interfaces) the other 4 wont come up, they appear as not connected.
I know you shouldn´t connect Switches to a FEX and yes, we disabled BPDU on the other vendor Switch so we were able to get the connection no refused by BPDU Guard.
So my question is if there is a limit and only you can have a certain number of interfaces up on a Port-channel.

Something like this:
N5K1===N5K2
 |       \   /    |  -- VPC-Porthcannel
N2K1      N2K2
| |   \ \  / /   ||  -- Port-channel

Switch-Switch -- Switches working as a VSS/Stack/StackWise/VPC

[Francesco Molino]

Hi

The links from your FEX to the host are configured as VPC or Port-channel?

Using vpc all ports should come up.

[Fernando Hernández]

They are in Port-channel.

Is it possible to configure them as VPC as well? I have both FEX as VPC from the Nexus 5K (Cross connection).
In other scenarios I have configured my hosts as a normal Port-channel from 2 different FEX, having my FEX cross connected to my Nexus 5K and with VPC. If possible to configure VPC as well from FEX to Hosts, what would be the difference from a normal Port-channel?

Regards

[Francesco Molino]

If all ports are facing the same host and on the host side you have a PO configured, you can configure vpc on your nexus side.
Here is the VPC design guide. You can look at enhanced vpc design:
https://www.cisco.com/c/dam/en/us/td/docs/switches/datacenter/sw/design/vpc_design/vpc_best_practices_design_guide.pdf