Live migration to a secondary VSL

[klasko16]

I am currently in a bind and believe I have a workaround to complete the task. I am short on QSFP to SFP+ adapters and the 4 I have are currently used as redundant VSS links in a 3850x stack. I would like to migrate the VSL off of the QSFP and just use the tengig interfaces instead. Am I able to create a second VSL (VSL 2 in addition to VSL 1) and have them both work at the same time or will this cause an issue? My plan is as follows:

Current configuration:

4 connections / 2 each switch in VSL 1

New Configuration:

Remove 2 of the connections, 1 from each switch to keep connection to VSL 1

configure second VSL, VSL 2, and include 4 tengig interfaces within

migrate 2 removed connections to the new VSL 2

migrate final 2 to VSL 2

remove vsl 1 

Will this work?

[balaji.bandi · Accepted solution]

No as per i know, this is will not work. You need to have downtime (one of the node to reboot  or make them offline )

If you have Dual Home connected your devices to 2 Core switches part of VSL,

VSL :

Switch 1 keep on so all working as expected.

Switch 2 - shutdown all the connected Interface (for safe )

Configure Switch1 new VSL with different ports, same case offline Switch 2 also.

Conneect switch 1 and switch 2 VSL link up. then no shutdown (ports shutdown on switch2)

Hope this is decent approach ?

[klasko16]

Thank you for the information, we were planning a migration to a nexus switch shortly anyways so we decided to expedite and now we won't have to worry about downtime as we migrate redundant connections to the nexus (also freeing up the QSFPs). I appreciate rapid response from all!

[Reza Sharifi]

Not sure if you can have more than one VLS portchannel up and running at the same time.

When you add the below command to the new portchannel, not sure if the switch will take it, as the other interface is a virtual link 1.

switch virtual link 2

 Also, if it takes the command, and you get to:

migrate 2 removed connections to the new VSL 2

Not sure if VSL 2 will come online until you reboot the chassis. 

I think, you need a maintenance window for this, and can not be done in production.

HTH

[kevin.g]

You would need to have downtime since you are not able to have 2 VSL active simultaneously.

Just adding the TenGig interfaces to VSL 1 is not possible as well, since TenGig and 40Gig interfaces are both supported but you cant mix them in a single VSL.