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VR!
May 1st, 2011, 01:53 AM
hello (:
i'm new in the forum and.. using ubuntu.
well.. my internet was fine.. until..
i had to work in the school so.. a teacher configured the internet settings.. for something .. ( i don't remember)
and everything was fine.
but when i returned to my house and conected my lap to internet (cable)
the internet didn't work.
can someone help me? ):



ubuntu@VR:/etc/network$ ifconfig
eth0 Link encap:Ethernet direcciónHW 00:1d:72:46:38:3c
Direc. inet:192.168.1.65 Difus.:192.168.1.255 Másc:255.255.255.0
Dirección inet6: fe80::21d:72ff:fe46:383c/64 Alcance:Enlace
ACTIVO DIFUSIÓN FUNCIONANDO MULTICAST MTU:1500 Métrica:1
Paquetes RX:23 errores:0 perdidos:0 overruns:0 frame:0
Paquetes TX:40 errores:0 perdidos:0 overruns:0 carrier:0
colisiones:0 long.colaTX:1000
Bytes RX:2653 (2.6 KB) TX bytes:8466 (8.4 KB)
Interrupción:17

lo Link encap:Bucle local
Direc. inet:127.0.0.1 Másc:255.0.0.0
Dirección inet6: ::1/128 Alcance:Anfitrión
ACTIVO BUCLE FUNCIONANDO MTU:16436 Métrica:1
Paquetes RX:156 errores:0 perdidos:0 overruns:0 frame:0
Paquetes TX:156 errores:0 perdidos:0 overruns:0 carrier:0
colisiones:0 long.colaTX:0
Bytes RX:11528 (11.5 KB) TX bytes:11528 (11.5 KB)

Iowan
May 1st, 2011, 03:09 AM
I presume your laptop was set up for DHCP addressing via Network Manager. You can check the connection to see if it is set to connect automatically.
Another thing you might try is to run a command from a terminal (Applications>Accessories>Terminal):
sudo dhclient

VR!
May 1st, 2011, 07:39 AM
I presume your laptop was set up for DHCP addressing via Network Manager. You can check the connection to see if it is set to connect automatically.
Another thing you might try is to run a command from a terminal (Applications>Accessories>Terminal):
sudo dhclient

uhm... i checked the DHCP adessing and i changed it to automatically. and i run the comand in a terminal.. and nothing change :/
do you have a nother idea? :S

Iowan
May 1st, 2011, 01:34 PM
What sort of messages popped up when you ran sudo dhclient?
ifconfig shows an IP address - is it correct for your network?
Can you ping the router?
Can you ping the internet by IP address (74.125.225.17)?

VR!
May 1st, 2011, 09:44 PM
What sort of messages popped up when you ran sudo dhclient?
ifconfig shows an IP address - is it correct for your network?
Can you ping the router?
Can you ping the internet by IP address (74.125.225.17)?

hello
when i ran "sudo dhclient" :

ubuntu@VR:~$ sudo dhclient
ubuntu@VR:~$
... i'm not very good at this, so..
how can i ping the router and the internet by IP addess?
(uhm.. and another question... how can i know if the IP adress that show "ifconfig" is correct for my network?)

Iowan
May 1st, 2011, 11:59 PM
... i'm not very good at this, so..
Neither am I... ;)
From a terminal, check route -n - post results, if possible.
Hopefully, one of the lines (probably the bottom one) will have a line with a "UG" flag. It will probably show a gateway of 192.168.1.1... but we'll see...
If it does, try (still from terminal): ping -c3 192.168.1.1
If you get replies - GOOD! Then try: ping -c3 74.125.225.17

No replies - not so good...


(I'm hoping the router is also the DHCP server. If the machine is properly set up for DHCP, it should get an address in the same subnet as the router/DHCP Server. If it does, then it will probably get routing information from the server as well... but somewhere along the way, something has apparently gotten changed to work with school network. If you can successfully ping the internet by IP address, then DNS will be next...)

VR!
May 2nd, 2011, 12:32 AM
Neither am I... ;)
LOL it makes me feel better .. i think (:



From a terminal, check route -n - post results, if possible.
Hopefully, one of the lines (probably the bottom one) will have a line with a "UG" flag. It will probably show a gateway of 192.168.1.1... but we'll see...
If it does, try (still from terminal): ping -c3 192.168.1.1
If you get replies - GOOD! Then try: ping -c3 74.125.225.17


well
here are the results:

ubuntu@VR:~$ route -n
Tabla de rutas IP del núcleo
Destino Pasarela Genmask Indic Métric Ref Uso Interfaz
ubuntu@VR:~$ route -n -
Uso: route [-nNvee] [-FC] [<AF>] Muestra las tablas de ruteado del núcleo
route [-v] [-FC] {add|del|flush} ... Modifica la tabla de ruteado para AF

route {-h|--help} [<AF>] Sintaxis detallada de uso para el AF indicado.
route {-V|--version} Muestra la/el versión/autor y sale.

-v, --verbose descripción amplia
-n, --numeric no se resolverán nombres
-e, --extend muestra otra/más información
-F, --fib muestra la base de información hacia adelante (predeterminado)
-C, --cache muestra la caché de ruteado en vez de la FIB

<AF>=Use '-A <af>' o '--<af>'; por defecto: inet
Lista de posibles familias de direcciones (que soportan el ruteado):
inet (DARPA Internet) inet6 (IPv6) ax25 (AMPR AX.25)
netrom (AMPR NET/ROM) ipx (Novell IPX) ddp (Appletalk DDP)
x25 (CCITT X.25)
ubuntu@VR:~$ ping -c3 192.168.1.1
connect: Network is unreachable
ubuntu@VR:~$ ping -c3 74.125.225.17
connect: Network is unreachable
ubuntu@VR:~$

uhm... at this moment.. i'm totally lost.. (:
i hope this is what you tried to say.

zepolmot
May 2nd, 2011, 12:40 AM
Keeping an eye on this thread, having the exact same problem.

Iowan
May 2nd, 2011, 03:01 AM
Hmmm...
That would fall under the:
No replies - not so good...
Routing table is empty - so machine doesn't know where to send packets. My machine yields these results:
Iowan@Hardy:~$ route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
169.254.0.0 0.0.0.0 255.255.0.0 U 1000 0 0 eth0
0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 eth0
Iowan@Hardy:~$
Another thing to check would be: less /etc/network/interfaces
You will see similar results if you prefer to use cat /etc/network/interfaces
Originally, this file would override Network Manager (not-so-much with later versions), so it might be helpful to see if it has a definition for eth0 interface.

Which version are you using - 10.04, 10.10, 11.04? (Network Manager is a little different between versions). There (probably) are some settings that need to be adjusted back. I presume your machine has an "auto eth0" connection.

VR!
May 2nd, 2011, 06:05 AM
Hmmm...
That would fall under the:
Routing table is empty - so machine doesn't know where to send packets. My machine yields these results:
Iowan@Hardy:~$ route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
169.254.0.0 0.0.0.0 255.255.0.0 U 1000 0 0 eth0
0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 eth0
Iowan@Hardy:~$
Another thing to check would be: less /etc/network/interfaces
You will see similar results if you prefer to use cat /etc/network/interfaces
Originally, this file would override Network Manager (not-so-much with later versions), so it might be helpful to see if it has a definition for eth0 interface.

Which version are you using - 10.04, 10.10, 11.04? (Network Manager is a little different between versions). There (probably) are some settings that need to be adjusted back. I presume your machine has an "auto eth0" connection.

i'm using 11.04, and yes my lap has an "auto eth0"connection.
here is what i found in interfaces:


auto lo
iface lo inet loopback

zepolmot
May 2nd, 2011, 07:22 AM
going to continue my lurking, less /etc/network/interfaces returns the same output that VR! is seeing

timefly
May 2nd, 2011, 02:29 PM
Try the following; if it works, repeat it each time you boot:

sudo ethtool -s eth0 port tp
This forces eth0 to use the twisted pair ("tp") port. For me, the network comes up instantly. No idea what port eth0 is trying to use in preference to the twisted pair because ... well, there isn't much of a choice between the one plug that it has. Besides, this worked just fine with 10.10, and if I boot into an earlier kernel it works fine, too.

The 11.04 livecd has the same problem. Anyway, I hope this works for you.

Cheesehead
May 2nd, 2011, 06:26 PM
Your /etc/network/interfaces file looks correct. Network Manager automatically discovers and configures interfaces that are not specified in that file.

Your ifconfig looks correct. It looks like Network Manager is probably operating properly, has discovered eth0 and configured as it has been told to.

So it's time to look in your Network Manager settings. Right click on the NM icon, choose 'Edit Connections' --> 'Wired' tab.

If you have more than one option, tell us. If your professor really knew his stuff, he would have created a new connection option for you to use instead of mucking with your default settings.

If you only have the option, 'Auto eth0', then 'Edit' it and look for any settings that look wrong. For example:
- 'Connect automatically' should be checked
- 'Use 802.1X security for this connection' should not be checked
- IPv4 Settings 'Method' should be 'Automatic (DHCP)

Iowan
May 2nd, 2011, 09:57 PM
If your professor really knew his stuff, he would have created a new connection option for you to use instead of mucking with your default settings. Speaking of whom...
Would the teacher be available to ask what changes were made?

(I haven't taken the Natty plunge yet - so I can't check a local machine.)