Cat5 extention 25 meters only getting 10mbs?

[#1]

I tried to cal the help line earlier as I thought my fibre was being really slow, but it turns out that my LAN connection is only connecting at 10mbps.
Its a 20 meter extension using CAT6 cable... is this right? My NIC is a 1gb type?
Thanks
Dan

[#2]

To state the obvious, try another cable and/or another PC. How do you know it's connected at 10mbps?

[#3]

I'm using a 35 meter Cat6 cable going from my PC upstairs to my router downstairs at the master socket and have it connected at 1gbps Full Duplex so it's either a faulty cable or a computer issue.
Try a different PC with the same cable. If the problem is still there then you need to replace the cable.

[#4]

I know im connected at 10mb as my NIC says so

[#5]

Quote

I know im connected at 10mb as my NIC says so

I once had a router that would not connect on a 20M ethernet cable......the router PSU was knackered....it would work on a 2M cable but not a longer one.
So one thing to try is another device on the other end of the cable.
Ian

[#6]

There are 3 causes that you can check relatively quickly depending on your free time.
It's either;
1. Router
2. Cable
3. NIC
All you need to do is a simple method of elimination, one at a time.
Try a different PC first with the same router and cable. If the problem still persists, try a different cable with 2 different PC's. If the problem is still there after that, try a different router.
And just to check, have tried forcing your NIC to negotiate a 100M/1G connection to your router?
Auto negotiate should work but it might be worth a try to just manually override and try to negotiate something higher and check the outcome.
Also, make sure the drivers are up to date for the NIC.