Hi there.  The GUI is showing you errdump information from the switch which is very general and undetailed at times and will not most likely give you the detail you need to see if the ISL links are stable.  You have a few methods: You can manually check it using the switch CLI command [fabriclog --show] this gives you a dated and time stamped per port log that details if a port sustained an offline event or link reset.  Looking at the output from right to left the port index field is the 2nd column, the far left is the time stamp and the section in the middle is the input and action. If you scroll up from the bottom of the command you will see dates which are important to confirm you are looking at current events. A rule of thumb here is If you see lots of activity for you ISL ports in particular port offline and LR_PORT events there may be some instability.  Also you can check the port errors using the [porterrshow] command again the port number is along the left side of the output and the counter of interest here is link fail. Please note that these counters can be historic and may need to be cleared to zero using the command [portstatsclear {slot/port number}] allow some time to pass and check for new link failure errors.  You can set up Fabric watch to monitor the error counters shown in the porterrshow and trigger alerts should error thresholds be broken this is a licensed product and here the configuration guide in case it interests you [URL]  Hope that helps
I have a couple of Brocade 6505 switches running on 2 distant sites, using DWDM and over that same DWDM physical link the network guys are running their ip connectivity. They're experiencing link loss problems, but so far I don't see any FC problems between my switches. How can I verify when ISL links are lost and restored?  Do I need to enable some sort of logging first or is this enabled by default? When I log on in the GUI I see some messages like NTP sync, zone activations, but no link loss problems.
How do I track link problems (ISL)?