Internet stopped working !!

[Guest]

Hey everyone,

lately I have had a problem with my internet, i dont know exactly when to it stopped working but im plugged, firefox works witha prox y, i tried to do the same with kubuntu puttign the proxy file in the System Preferences but no results i cant access the adept databases nor the Kopete.

charlie@Ego:~/Documentos$ ifconfig
eth0 Link encap:Ethernet direcciónHW 00:1a:80:b7:cf:29
inet dirección:129.153.198.227 Difusión:129.153.199.255 Máscara:255.255.254.0
dirección inet6: fe80::21a:80ff:feb7:cf29/64 Alcance:Vínculo
ARRIBA DIFUSIÓN CORRIENDO MULTICAST MTU:1500 Metric:1
RX packets:33804 errors:0 dropped:0 overruns:0 frame:0
TX packets:8759 errors:0 dropped:0 overruns:0 carrier:0
colisiones:0 txqueuelen:1000
RX bytes:8617751 (8.2 MB) TX bytes:1321360 (1.2 MB)
Interrupción:17

lo Link encap:Bucle local
inet dirección:127.0.0.1 Máscara:255.0.0.0
dirección inet6: ::1/128 Alcance:Anfitrión
ARRIBA LOOPBACK CORRIENDO MTU:16436 Metric:1
RX packets:68 errors:0 dropped:0 overruns:0 frame:0
TX packets:68 errors:0 dropped:0 overruns:0 carrier:0
colisiones:0 txqueuelen:0
RX bytes:3400 (3.3 KB) TX bytes:3400 (3.3 KB)

I try this and says its not configured, any ideas?

charlie@Ego:~$ sudo ifdown eth0
[sudo] password for charlie:
ifdown: interface eth0 not configured

Thanks in advance