Cannot connect to ethernet

[harisankar98]

Hi,
Am using ubuntu 8.10. I am not able to connect to ethernet device.. the weird thing is that sometimes, it works fine!!!! and most of the time it does not..

The network manager icon on the taskbar shows that there are no active valid connections.. it is the same when am able to connect or not..
But when i tried booting from the ubuntu live cd, i was able to see active wired connection at the network-manager and the connection information is saying that it is using driver 'r8169'..
something like that is not shown on ma system.. ( i installed ubuntu on ma system using the same live cd ) ..

ping 192.168.1.1 returns.. connect: unreachable..

now, the weirdest thin.. sometimes am able to ping successfuly and even at that time, the network manager icon shows am disconnected.. last day wen i was connected like this, i upgraded to 9.04.. but wen i rebooted, the connection was gone..

Pls help me..

[harisankar98]

forgot one thing. the network adapter works fine under vista.. its Realtek RTL8168B/8111B Family PCI-E Gigabit Ethernet ..

ma system is a laptop.. the MSI GX620...

[fornix]

Please paste the output of the following

$ ifconfig -a

[harisankar98]

hey... all of a sudden the ethernet worked again and i am now posting this from ma updated Jaunty...

here is ma ifconfig -a

eth0 Link encap:Ethernet HWaddr 00:21:85:48:f0:d7
inet addr:192.168.1.4 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::221:85ff:fe48:f0d7/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:1244 errors:0 dropped:0 overruns:0 frame:0
TX packets:1093 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:929092 (929.0 KB) TX bytes:264825 (264.8 KB)
Interrupt:248 Base address:0x8000

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:10 errors:0 dropped:0 overruns:0 frame:0
TX packets:10 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:580 (580.0 B) TX bytes:580 (580.0 B)

pan0 Link encap:Ethernet HWaddr d6:7a:3e:f9:9f:33
BROADCAST 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 txqueuelen:0
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)

ppp0 Link encap:Point-to-Point Protocol
inet addr:117.196.134.183 P-t-P:117.196.128.1 Mask:255.255.255.255
UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1460 Metric:1
RX packets:989 errors:0 dropped:0 overruns:0 frame:0
TX packets:938 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:3
RX bytes:883938 (883.9 KB) TX bytes:214690 (214.6 KB)

wlan0 Link encap:Ethernet HWaddr 00:16:ea:5e:1e:f8
UP BROADCAST 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 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)

wmaster0 Link encap:UNSPEC HWaddr 00-16-EA-5E-1E-F8-00-00-00-00-00-00-00-00-00-00
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 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)



if i remember correctly, earlier when there was no net, the ifconfig eth0 returned details without the ip, broadcast and netmask..

here is ma /etc/network/interfaces

auto lo
iface lo inet loopback


iface dsl-provider inet ppp
pre-up /sbin/ifconfig eth0 up # line maintained by pppoeconf
provider dsl-provider

[harisankar98]

forgot one more thing.. now the network manager is showing the connection and the connection information is showing that it is using the r8169 driver..

lemme reboot once again and check if its not working..

[harisankar98]

rebooted.. and not working.. :D.. this is weird.. this is the output of ifconfig -a now..

eth0 Link encap:Ethernet HWaddr 00:21:85:48:f0:d7
inet6 addr: fe80::221:85ff:fe48:f0d7/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:14 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:3204 (3.2 KB)
Interrupt:248 Base address:0xe000

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:4 errors:0 dropped:0 overruns:0 frame:0
TX packets:4 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:240 (240.0 B) TX bytes:240 (240.0 B)

pan0 Link encap:Ethernet HWaddr aa:ad:aa:f1:f3:b7
BROADCAST 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 txqueuelen:0
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)

wlan0 Link encap:Ethernet HWaddr 00:16:ea:5e:1e:f8
UP BROADCAST 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 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)

wmaster0 Link encap:UNSPEC HWaddr 00-16-EA-5E-1E-F8-00-00-00-00-00-00-00-00-00-00
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 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)


see the difference..

[fornix]

When you are not connected, does a manual down and up of your interface help?


$ sudo ifconfig eth0 down
$ sudo ifconfig eth0 up

If that doesn't work, next step would be to manually edit your /etc/network/interfaces file and add the following entry


iface eth0 inet dhcp

Assuming you are using DHCP instead of manual ip address.

Then, try disabling (down) and enabling(up) your network interface. The first commands.