Ubuntu

Ethernet not working

Asked by Benjamin

Just installed Hardy Heron on self built desktop. Am not able to connect to my network via ethernet. Other computers can connect both with wireless and same router port and cat5. Comp has no other OS for testing, though booting to live CD also fails.

I've run lspci and ifconfig (output included).

I assume this is answered somewhere but everything I find ends up being either a wireless issue or a network issue.

lspci | grep -i ehternet
00:14.0 Bridge: nVidia Corporation MCP51 Ethernet Controller (rev a3)

ifconfig -a

eth0 Link encap:Ethernet HWaddr 00:1f:c6:1a:7c:ca
                 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
                 RX packets:0 errors:0 dropped:0 overruns:0 frame:0
                 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
                 collisions:0 txquelen:1000
                 RX bytes:0 (0.0B) TX bytes:0 (0.0 B)
                 Interrupt:23 Base address:0xc000

eth0:avahi Link encap:Ethernet HWaddr 00:1f:c6:1a:7c:ca
                inet addr:169.254.7.220 Bcast:169.254.255.255 Mask:255.255.0.0
                UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
                Interrupt:23 Base address:0xc000

lo Link encap:Local Loopback
                inet addr:127.0.0.1 Mask:255.0.0.0
                inet6 addr: ::1/128 Scop:Host
                UP LOOPBACK RUNNING MTU:16436 Metric:1
                RX packets:0 errors:0 dropped:0 overruns:0 frame:0
                TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
                collisions:0 txquelen:1000
                RX bytes:0 (0.0B) TX bytes:0 (0.0 B)

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Tony Mugan (tmugan) said : 		#1

169.254.7.220 on your ethernet adapter implies that it could not find a DHCP server to grant an IP address.

You could try booting from the Ubuntu liveCD to see if it detects and picks up a valid IP address.
(Generally expecting a 192.168.x.x on a home network by default but it depends on the router you are using)

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Benjamin (laroque-email) said : 		#2

I tried the Ubuntu liveCD and got the same result. I'm using a Linksys WRT-54g with, as far as I know, default settings on the wired connections so the local IP should be 192.168.1.xxx.

I've also tried: 'dhcpcd eth0' but that command is not available (and I can't apt-get it without a connection).

I don't know if this is a problem or only another indicator that I'm unable to find a DHCP server, but I checked in /etc/network/interfaces and there is no entry for eth0.

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Juraj Lukac (hrasko) said : 		#3

have you tried dhclient instead of dhcpcd ? and if there is no record for some network interface in the /etc/network/interfaces file you can create those records by yourself.

Revision history for this message
Benjamin (laroque-email) said : 		#4

Well I'm not sure exactly what I did to fix it, but I went in rechecked my router settings that enable dhcp server etc. and it seems to be working now. Wish I could say what the problem was but all I'm sure is that it was in the router somewhere.

Thanks to both of you for your help.