PS3 "Ethernet Cable not connected" problem

The PS3 keeps showing the fault in the top right corner of the screen "ethernet cable not connected" when the cable is clicked into position in the router and ps3 and the wire has been tested between the router and a computer. The green flashing light flashes for around 3 seconds then will stop for roughtly 3 seconds and then start again. this process is repeated constantly.

The wireless connection works fine but i prefer wired to stop lagging on the online games.

Any information would be helpful?

DHCP problem assigning an IP address to the PS3 by the sound of it - log in to your router and have a check around any wired connection settings to see if there's a problem.

Also check the wired connection settings on your PS3.

Can you connect a PC or other device to the router using teh same cable and ethernet port?