I have an Ubuntu 12.04 box with two "Intel Corporation I350 Gigabit" ports. These work fine with my cable modem at 1Gbps speed. I tried to have my old Linksys wrt54g router in between. The wireless connection to the router works fine, but I cannot get the Ubuntu box to connect to the router. I tried few cables, but it seems the problem is with the configuration on the Ubuntu box.
Right after the cable is plugged in the port light changes from amber to green. Also ethtool shows that link has changed to 100mbps.
Settings for eth0: Supported ports: [ TP ] Supported link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Full Supported pause frame use: No Supports auto-negotiation: Yes Advertised link modes: 100baseT/Full Advertised pause frame use: Symmetric Advertised auto-negotiation: Yes Speed: 100Mb/s Duplex: Full Port: Twisted Pair PHYAD: 1 Transceiver: internal Auto-negotiation: on MDI-X: Unknown Supports Wake-on: pumbg Wake-on: d Current message level: 0x00000007 (7) drv probe link Link detected: yes
Also ifconfig shows some packets going both ways at the link level (TX and RX numbers). However I cannot ping the router or connect to internet. ping gives "No network found".
Anything else I can check?