Adding additional trunk

[James van Thillo]

Hello,

I have a couple of 91** MDS switches that are up and running in the same fabric.  I want to add a second ISL between the two for redundancy and because the first ISL is running at a lower speed then it should.  I am told changing the speed is disruptive.

Is adding a second trunk between the two disruptive?   Once the second trunk is in place will the switches just start load balancing/HA it?  Are there any license issues?

Also when the second trunk is in place can I change the speed of the first one without it being disruptive?

Any Gotcha's to look out for?

thanks,

[Walter Dey]

I think this is a routing (FSPF) topic: you add a second ISL which has a higher speed, therefore lower cost. All the traffic will now go over this new link; then you fix the speed on your original ISL, making it identical to the new one; from this moment on, traffic will be load balanced over the 2 equal cost (and speed) links.

No license required. Best practise would of course be to create a port channel.
 

[James van Thillo]

Thanks very much Walter,

[Keny Perez]

Please mark the question as answered for future users to see you found the information you were looking for.

-Kenny