Lag over ethernet, wireless is ok?

[Scythe]

Hi,
I live in a student house and we have the following set up

phone line -> O2 Router ----(ethernet)---> My Router /Switch (WRT54GL on ddwrt)----(ethernet/wireless)---> My pc.

If I use an ethernet cable from my pc to my switch, in BF3 I get lag. Every few steps, it jolts a step back. It's approximately every 3 seconds. However, I just swapped to my wireless card to connect to the same router (my WRT), and BF3 is playing fine?

1 week old Windows 7 install, I also had to reset the TCP/IP stack to get browsing to work when I moved the machine up to uni. I could ping but I couldn't browse any sites.

Anyone have any ideas what's up with it? The pc is located right next to the WRT router

Much appreciated.

 

[dfarrall]

Dodgy cable/port/nic by the sounds of it.
Try a different cable, port and see if other devices are fine via Ethernet.

 

[AMMUT]

Do you see the same thing happening if you plug your pc directly into the O2 Router?

 

[Scythe]

Do you see the same thing happening if you plug your pc directly into the O2 Router?

Just plugged directly into the router and it's failing to join games at all now

EDIT: Must be the connection sorting itself out, it's working fine. Just testing with the original set up on the same server to see if it's doing it again.

 

[bledd]

Install latest NIC drivers (from the manufacturer site, not the motherboard site)
Try another cable

A quick way of testing ping, open a cmd window

type in..

ping google.co.uk -t

It will keep pinging forever until you press CTRL + C or close it, you'll see if it's stable or not