I'm trying to create an ISL between these two devices. I've set the port on the 1620m to R_port and Brocade interconnect mode with Append zone. I've changed the connected port on the 4100b to 1gb. When I connect the fibre I just get a permanent message in Sanvergence Manager saying "reconfiguring fabric". Can anyone help? I'm pulling my hair out with it now !!