Very Strange network problems, help required!

Chris1712 · 28 Sep 2008 at 15:28

Morning all, we've just had a move around in our student house and subsequently one machine is on a different cable which is hella long all the way down the other end of the house.

Basically, his pc is experiencing extremely slow network transfers, and internet connectivity. Pinging other machines/router is just fine, but it maxes out at about 30KBps on internal transfers AND internet downloads?

I've tried my laptop on the very same cable and network performance is as normal, full 20mb virgin on the internet side and about 6-8mbps between pc's. So i guess its not the cable. Also tried it on two NIC's in his machine, one is slightly faster but still only about 50KBps, the onboard one is slightly faster.

Tried now in Ubuntu, same problem on his machine, so i guess its a hardware issue, but what are the chances of both NIC's dying like this? Anything else to try?

Network equipment is a WRT54GL (tomato) and a netgear gigabit switch. Ip's etc. are fine and no QoS has changed on the router, also the connection is coming up at 100mpbs full duplex which is normal.

Stumped. Any ideas?

blueboy2001 · 28 Sep 2008 at 16:49

It does sound very much like a cable problem, even though the laptop worked OK.

What about trying the PC on a short patch cable direct into the router or switch?

Chris1712 · 28 Sep 2008 at 16:51

blueboy2001 said:
It does sound very much like a cable problem, even though the laptop worked OK.

What about trying the PC on a short patch cable direct into the router or switch?

Fixed it now by adding a switch inbetween, that makes absolutely no sense to me but its sort for now!

It goes, Virgin Cable>WRT54GL>Gigabit switch>massive cable whole length of house>old crappy netgear switch>PC and it works fine. Speeds back etc. Makes no sense to me but hey its working now so i'll leave it alone!

rayer · 28 Sep 2008 at 16:52

How long is 'helluva long ?' in regards to the cable length ?

Chris1712 · 28 Sep 2008 at 16:55

rayer said:
How long is 'helluva long ?' in regards to the cable length ?

I've no idea, i would say at least 40m if not more. Regardless its fine on my laptop and going straight into a switch, just not going into his PC!

3dcandy · 28 Sep 2008 at 17:14

must be just losing packets due to cable length! The switch is obviously coping better with the cable length

Chris1712 · 28 Sep 2008 at 17:22

3dcandy said:
must be just losing packets due to cable length! The switch is obviously coping better with the cable length

Thats what i thought initially, just seems absolutely crackers that my laptop is fine, as is the old switch. His PC is a bit old skool but its still a weird problem, i wouldnt expect the difference to be so large if it was due to packet loss.

3dcandy · 28 Sep 2008 at 18:10

just got a better nic in your laptop!
older stuff tends not to work aswell!!!

rayer · 28 Sep 2008 at 18:47

Cat 5 is ok until about 90 -100 metres. Then it starts to play around.

Sounds like the NIC.

Then again, it could be many things like the router might be dropping the packets for some reason which means the old PC has to then resend the traffic or the speed/duplex on the NIC/ Router interface. Anyway, if its working now with the PC plugged into a switch, and then into the router, excellent, but still got me thinking why though ?

Probably come to me at 2am in the morning.