Reseated Cat5/5e in switch, now only getting 100m full duplex

Last night me and my boss decided to re-organize where the Ethernet cords were plugged into the switch so we could mark them down and know where they were going for future reference.

When we turned everything back on a lot of the ports were marked as "yellow" or full duplex 100mbps. Even the one that's plugged into the router, which goes to the WAN.

Before we re-arranged everything we were getting "green" 1000mbps full duplex on everything. So the switch, router, and wan can and did handle it.

Whenever I change a port from 100 to 1000 it just becomes inactive. It says its 1000 full duplex, but doesn't work anymore until I change it back. I tried different wires, and even switched the ethernet cords around in the ports, but got the same results. Which leads me to believe that it might be the PCs themselves. So I went into the NIC config and changed the speed settings to 1.0gig full duplex, but still same results. All our cables are CAT5/5e, so maybe try CAT6?

Anyone have any ideas?

ISP: Comcast Business Class
Router: Fortigate 110c
Switch: 3com baseline switch 2948-sfp plus

All Cables are CAT5 and CAT5e
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More about reseated cat5 switch 100m full duplex
  1. You should have no trouble with your cables...technically cat5 won't work according to the specs but is does work over short distance. Cat5e is rated to 1g and cat6 will work no better.

    Be sure all cables have all 4 pair of wires. Cheap ones only have 2 pair. Also be sure all your cable are straight though. A cross over cable is only designed to cross 2 pair so it can confuse the mdi/mdix and you get 100m.
  2. Actually it ended up being the PCs. They won't go 1000mbps since they don't have gigabit NIC cards installed. So when I changed the settings in the switch it would just make them inactive since they can't go that high.

    Definitely going to run cable diagnostics though and check that out. It's a mess, and I know out of all the hardware we are running our cables are old and bent all over. Probably causing slowdown.
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