10g Multimode Fiber Link Between Brocade 7450 and 7250 - Link up only on one side

Hey all,

Posting here because I'm at the end of the troubleshooting I'm knowledgeable about and Brocade support wasn't much help.

My configuration: Brocade 7450, port 1/4/1, 10GE LR 10km SFP+ Brocade 7250, port 1/2/1, 10GE LR 10km SFP+ Multimode Fiber No additional port configuration, both ports show as 10gig.

When these are connected, I get links up on the 7250, with a LK-DISABLE status. The 7450 port 1/4/1 shows as down. When I disable 1/4/1, port 1/2/1 on the other switch goes down, so I know they are connected.

I have tested the SPFs by plugging them into the same switch and looping them, both ports show as up. (One LK-DISABLE to prevent the loop) But it won't work between the 7450 and the 7250. Fiber vendor is confident their physical is correct. I have the correct licensing on both of my Brocade switches. Firmware on both is the same, version 08070e which is a known good version.

Am I missing something here? I've got this working between other Brocade switches just fine. About to test the fiber with Cisco switches to make sure it's not a Brocade configuration/bug but I'm sure it will be.