Cannot connect to internet Ubuntu 8.04

**babelproofreader** · November 18th, 2008

I have two Ubuntu boxes both with Ubuntu 8.04 on them, but one cannot connect to the internet through the same wired connection. For the one that works ifconfig gives

eth0 Link encap:Ethernet HWaddr 00:16:e6:52:3a:c5
inet addr:87.250.172.31 Bcast:87.250.172.255 Mask:255.255.255.0
inet6 addr: fe80::216:e6ff:fe52:3ac5/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:32108 errors:0 dropped:0 overruns:0 frame:0
TX packets:11960 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:13619625 (12.9 MB) TX bytes:2438671 (2.3 MB)
Interrupt:21 Base address:0x6000

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:1284 errors:0 dropped:0 overruns:0 frame:0
TX packets:1284 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:64200 (62.6 KB) TX bytes:64200 (62.6 KB)

and the content of /etc/network/interfaces is

auto lo
iface lo inet loopback

whilst for the one that won't connect ifconfig gives

eth0 Link encap:Ethernet HWaddr 00:0b:6a:ec:11:c5
inet6 addr: fe80::20b:e6ff:feec:11c5/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:6048 errors:0 dropped:0 overruns:0 frame:0
TX packets:630 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:516597 (504.4 KB) TX bytes:42339 (41.3 KB)
Interrupt:18 Base address:0xcd00

eth0:avahi Link encap:Ethernet HWaddr 00:0b:6a:ec:11:c5
inet6 addr:169.254.7.193 Bcast:169.254.255.255 Mask:255.255.0.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Interrupt:18 Base address:0xcd00

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:1206 errors:0 dropped:0 overruns:0 frame:0
TX packets:1206 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:69938 (68.2 KB) TX bytes:69938 (68.2 KB)

and the contents of /etc/network/interfaces is

auto lo
iface lo inet loopback

iface eth0 inet dhcp

auto eth0

In all other respects the network settings are exactly the same in admin-network, admin-network tools and preferences-network proxy for both computers with regard to IP addresses, DNS servers etc so I don't really understand why I am having problems connecting one of the computers. Any help would be greatly appreciated.

**superprash2003** · November 18th, 2008

how do you connect to the internet?? via a dialer in windows xp?? do you use pppoeconf in ubuntu?

**Iowan** · November 19th, 2008

Depending on how you connect to internet (that address doesn't look like a "normal" router-DHCP-assigned address), some modems "lock onto" a MAC address and must be reset (power cycled) to recognize a different MAC. If you reset the modem with the second one attached, it might work - but the first might not be able to connect without (again) resetting the modem. If that happens, you might consider a router as a buffer.