How to check port is working

Hi,

First, turned it down from device manager and turn-up after 10 sec.
second, take it off from old port and try it plugging into new port and see if that wroks.
third, try using new cable(sometime cables go faulty).

You could plug a loop back into the port and run this command: "system health external-loopback interface fc x/x"

Hello,

I'd recommend going with what Amol stated. I'd also add that I would move the connection to another port on another module if possible to ensure that the module itself isn't having issues.

Please also keep in mind that there are some other things to keep in mind:

1) the port must be enabled for it to work
2) if it is a port that has ports on demand like a 9124, you need to have a license for the port to work
3) you also have bandwidth constraints on ports that can cause a port to not work if the other ports are taking all the available bandwidth
4) ports can be auto disabled if the switch finds a problem with the connection going over them

An additional thing to keep in mind is that quite often SFPs are replaced when they are fine. A recent large number of "bad" SFPs were returned and I tested them. Over 90% of them worked fine. Other issues such as loose cables or bad connections on patch panels probably caused most of the issues. Moving connections is the best way to ensure the SFP is bad or good.

Thank you.

Kind of a stupid suggestion - but on the Cisco switches you might want to make sure the port (not the cable) has not been pulled a little out of place. Those GBIC modules are not the snuggest of fits and I've seen a few cases where a port may be pulled just loose enough to lose connectivity.

The cable/GBIC connection is stronger than the GBIC/switch connection so in a cable tug-of-war the GBIC most often comes loose.

This is my trouble-shooting list on bad ports after confirming there are no hardware (host HBA or switch port) errors and that the link is indeed dead:

1) Push the port to confirm it is snug (there won't be any link lights on the switch)
2) Confirm light is coming through the cable (you may still have light and things not work but good indicator if the cable may be damaged bad if you have no light)
3) Move the cable to another port.
4) Run new cable and test to old and then new port.
5) Replace the HBA card (or try different port if available on the host)