F Port-Channel Trunking vs. Non Trunking

One of the fun things I get to do is learn about Fiber Channel technologies. Today I’ve been configuring a UCS chassis with two Fabric Interconnects to two MDS 9148 SAN switches.

I’ll go into it a bit more on another post, but after I was configuring it reading some great documentation, I didn’t understand what the difference between trunk mode and non trunk mode was going over a port channel.

So here it is based on what I read here.

F Port-Channel: This refers to taking two physical cables and creating a fat pipe with them. So if you have two 8Gbps FC links, you can combine them to a nice big 16Gbps FC pipe. Its similar to ethernet port-channels but you do it with the SAN.

Now, you may have different VSANS that you want to go over this pipe. Well, if you are in non-trunking mode, you can not do it. You are only allowed one VSAN. In UCS, this is the default setting. No trunking. This usually works fine and in my environment I have no reason to change it.

However, if I had multiple VSANS then I’d want to make a trunk out of it. This requires a bit extra wizardry on UCS. But it is documented here.

  • Jeff Drury

    Nice post Vallard, Google pointed me your way when I was looking for the right docs.

    • Anonymous

      Ha, thanks Jeff, and thanks for helping me figure it all out!