Brocade fabric switch error (AD VF conflict)

Just had this error on an ISL link between two switches, my initial Googling didn’t yield too much of use so I thought I may as well blog it and the solution (I used) here, hopefully be of help to others.

The scenario: Connecting a new Brocade 5100 switch with no configuration to an existing Brocade 5000 based fabric that uses Administrative Domains (AD).  Both the new 5100 and the 5000 are running the same release of FabOS, the 5100 has nothing but the barest of bare configurations (it’s IP address and authentication credentials).  With the ports connected, a switch show on the switches yields the following for the ISL port between them:

5100

LS Attributes:    [FID: 128, Base Switch: No, Default Switch: Yes, Address Mode 0]

Index Port Address Media Speed State     Proto
==============================================
  0   0   0a0000   id    N4   Online      FC  LS E-Port  segmented,(AD VF conflict)

5000

Address Mode:    0

Index Port Address Media Speed State     Proto
==============================================
  0   0   030000   id    N4   Online      FC  LS E-Port  segmented,(AD conflict)

I have included the last line of the information block as it gives a clue, the 5100 has additional lines here and more features, FID relates to Virtual Fabrics, a feature not supported on the 5000 in this case (I suspect not supported at all on the model but am not 100% sure of this).

The big clue for me is the “(AD VF conflict)” a bit of Googling revealed that it is not permissible to use Virtual Fabrics and Administrative Domains, I believe VF is the new AD, and hence mutually exclusive.  So the fix?

Simple, disable one or the other.  Now as the established fabric in this case is utilising AD, I am not going to disable that (as much as I would love to bin it 🙂 ) so disabling the VF on the new 5100 is the order of the day.  This is thankfully simple enough to do.

Use the command

fosconfig --show

to list all configured VFs and remove all but the default ones.  If you haven’t configured any, you won’t have any.

fosconfig --disable vf

will prompt you to confirm you wish to disable VF, this will require a reboot of the switch you are on, and a full reboot it is too, it will stop passing frames.  Once the reboot has completed, the switch should come back up and happily merge with your existing fabric.

Hopefully this will be of use to someone else, and as with anything I write on here, use this information at your own risk, I am not going to accept responsibility if you wipe out your companies fabric, or set fire to your gran doing this.