A quick fix for a bad switch port
This post is a short one, but hopefully still valuable. I spent 30 minutes troubleshooting a flapping switch port in the lab this week. I was attaching a headless test device to a 3750G and I couldn’t see the status of the NIC from the tester’s perspective.
So one crash cart and a bit of port-swapping later, I found the problem. It was a dodgy switch port and swapping to another port (with identicial config) solved the issue. Then it hit me. I had hit this particular bad port before but didn’t follow up. This is network Karma, and I deserved that wasted 30 minutes.
So what next? The ‘right’ thing to do here is to RMA the switch, but I have plenty of ports in the switch stack and the RMA isn’t a priority. I’ve configured the port using ‘description ** Faulty Port **‘, but that’s not enough.
Then I remembered a bag of RJ-45 connectors I had in the cabinet, and inserted a single connector to occupy our dead port, port 12.
This is a quick fix but should make it harder for the next admin (or me) to re-use that bad port.
3 thoughts on “A quick fix for a bad switch port”
i use the same to “block” rj-45 ports when there are dual-medium ports available and the sfp ones are used
That’s a nice way to prevent the inevitable on a sup module. No if only we could find a cheap way of blocking the SFP cage!. Thanks for the comment.
I just ran across this post. And just for the fun of it, I tried plugging in an rj45 into the spf cage. It almost got stuck! With a little bit of tape around the rj45, this might fit the bill if you want to block the spf cage.