UCS FI - Different Northbound Switches

[Ikester]

Hello,

We currently have a pair of 7K switches northbound with a set of vlans trunked on them.  We have a port channel setup to those 7Ks.   There is a legacy switch with a legacy vlan 417 that cannot be extended to the 7Ks.  I can run a 1GB cable uplink to the legacy switch from the FIs and configure vlan 417 to only use that new uplink using LAN Uplinks manager.  

My question is, what happens to the other existing vlans that are currently using the port channel?  They were never configured to use any specific uplinks.   Will they attempt to use the new uplink that is connected to the legacy switch causing an outage?

[Wes Austin · Accepted solution]

You will use the LAN uplinks manager to statically pin VLAN 417 to the 1GB uplink. This will only pin VLAN 417 to the new uplink and all other VLANs will continue to pin to your N7K Po.

Your existing vNIC will continue to pin to the N7K uplink, however, if you want to use the new VLAN 417, you will need to create a new vNIC that only allows that VLAN. When a vNIC attempts to pin to an uplink (individual or port-channel) it will check the following:

1. Which of these uplinks is in the "up"state?

2. Which of these uplinks allows ALL of the VLANs allowed on my vNIC?

3. Which of these uplinks, that allow ALL of my VLANs, is the least utilized?

Once you create a new vNIC, only allow VLAN 417, it will successfully pin to the 1GB uplink without ENM source pinning failure. This can be done without taking an outage, however, I would recommend conducting the change during off-hours and/or opening a TAC case if you have questions.

Reference:

Deploy Layer 2 Disjoint Networks Upstream in End Host Mode

[Ikester]

Thank you for the clarification that makes total sense!  That sounds like it will be a disjointed L2 Network configuration correct?

[Wes Austin]

Correct