I have a strange issue that came up this morning (Happy Monday!).
One wing of this building is serviced by a small network closet that feeds to our main closet via 2 - cat5 cables (Only one is for back up)
This morning no one in that wing can get network access. I power cycled the switches in the small closet as well as the main closet. No change.
Next I connect the cat5 feed to a different switch, in fact I tried several known good switches. No solid link. But it does flash on every 5 seconds or so.
Tried different patch cables, no change. I even tried a cross-over cable even though my switches (Linksys SRW2024) don't require them.
Finally I connected my laptop to that cat5 feed, and that seems to work fine. I get a link, I get connectivity. If I plug that same cable to any switch in the small closet, no connection. None of the switches are looped, and I have tried 2 known good switches that were not connected to anything else.
Same symptoms on the second cat5 cable.
So, I'm thinking if this is a cable issue, why does the laptop work with no issue?
Makes me want to punch a dolphin