07-26-2011 09:49 PM
I am trying to connect a new Brocade 5300 switch (FOS 6.4.0c) with an existing Brocade 4900 switch (6.1.1a). The domain IDs are different for both the switches. The fiber is connected from port 32 of Brocade 5300 to port 40 of Brocade 4900. And also port 34 from 5300 to port 42 of Brocade 4900. Though the logins are happening, the ISL is not getting established. The port remains in In-sync mode. I see the continous message in the event log of 5300 saying that "Unstable link detected during Merge" on the. The 4900 switch event logs show messages "negotiated VC_RDY (Mode1). I tried setting the port speed to 4Gbps on both the switches. Please suggest what things I need to consider to have ISL established.