Trouble shooting DSL connection in Ubuntu

[skghosh44]

Today while I was surfing the net on Ubuntu OS , my system shutdown due to UPS failure. When I restart the system, DSL modems Lan light not glowing. I cant connect the net. I tried to reconfigure the Setting by command "pppoeconf" it detect the Lan card but failed to continue the setting with a msg " Check your modem connection or cable or another connection is running".

I restarted the system in Win OS. there it is OK and I am writing this thread in Win OS.

I cant understand what is the problem. Any One any solution please ?

[praka123]

fsck ur ubuntu via livecd.
boot Ubuntu live cd and open a terminal run:

sudo fsck.ext3 -fvy /dev/sdx

^where /dev/sdx is ur hdd ubuntu partition.

If ur modem dsl light is showing up,then ur net is up.Ubuntu can connect.why do u run pppoeconf again
if u try to connect via pon dsl-provider,what is the error message showing in "plog" command?open a terminal and observe.

also,with dsl light glowing only does u try to configure via pppoeconf

[skghosh44]

Today morning when I switched on my pc in Ubuntu, !st I looked in the LAN light and it is glowing. I start the net and it is connected. Now, I can't understand what was the problem last night, today which is automatically fixed. I think there was a ghost in the modem last night for Ubuntu. Because it was fine in WIN OS.
OK. thanks god without any hassel now it is running.

[gary4gar]

Originally Posted by skghosh44

Today morning when I switched on my pc in Ubuntu, !st I looked in the LAN light and it is glowing. I start the net and it is connected. Now, I can't understand what was the problem last night, today which is automatically fixed. I think there was a ghost in the modem last night for Ubuntu. Because it was fine in WIN OS.
OK. thanks god without any hassel now it is running.

well, if this happens next time, try boot into windows & see if it works there.

if it works in windows & its then Ubuntu problem
if NOT, then your connection might be down from ISP end

[skghosh44]

Originally Posted by gary4gar

well, if this happens next time, try boot into windows & see if it works there.

if it works in windows & its then Ubuntu problem
if NOT, then your connection might be down from ISP end

Immediately I checked the status in Windows and there it was fine. Hence I was nervous whats the wrong with ubuntu.

[praka123]

@ghosh:make sure ur lan is up @ boot by seeing ifconfig o/p
also if u shutdown ubuntu dirty,boot with a livecd and run a fsck.ext3 -fvy /dev/xxx ,make sure ur hdd ubuntu is NOT mounted in livecd.

also if lan is up,u can see the o/p of "pppoe-discovery" for whether the connection is able or not.

[gary4gar]

how to bring a connection up at boot time?
sat eth1

[The Unknown]

This is not at all OS problem. This happens when the PC isn't reset properly. Suppose a power failure occurs and your UPS did not give the power immediately and a msecs after that, then the mobo isn't reset properly which leads to non-working of the LAN card. After switch-off and switch-on of the PC, its back to normal.

[mehulved]

Originally Posted by skghosh44

Today while I was surfing the net on Ubuntu OS , my system shutdown due to UPS failure. When I restart the system, DSL modems Lan light not glowing. I cant connect the net. I tried to reconfigure the Setting by command "pppoeconf" it detect the Lan card but failed to continue the setting with a msg " Check your modem connection or cable or another connection is running".

It's not a big issue. Just that your connection wasn't terminated last time because your PC shutdown due to UPS failure before it could terminate the connection.
So, when your PC restarted the connection wasn't on from the client side but at the ISP end it will still on, thus the error message.
just typing

poff dsl-provider

would have solved it IMO.

[Rahim]

Originally Posted by mehulved

So, when your PC restarted the connection wasn't on from the client side but at the ISP end it will still on, thus the error message.

Is it possible? If the modem is powered-off then both connections would be terminated, isnt it?

[gary4gar]

All TCP connections are required to be terminated explicitly, however is a client does not reply to server for a longer period of time the connection is terminated by the client.

This period of wait by server is called time out.
if client disconnects & connected within the period of timeout he may experience problem with most servers.

I am not a expert in networking, so this is my half knowledge.
@Experts
Please point out, any errors

[skghosh44]

On that that day night I tried several time to reestablish the LAN in Ubuntu by restarting the PC, Modem, changing the cable etc also tried to configure the "pppoeconf" all are useless. During the experiment I restart in Windows, as soon as the booting process over LAN/ethernat light is OK and net is connected with in a seconf.

Again I rebooted in Ubuntu to see what is the condition. NO, the LAN/Ethernet light is not glowing on modem as well as LAN port on the PC.
Next day morning there is no problem. The problem is solved automatically.

@mehuldev
So, when your PC restarted the connection wasn't on from the client side but at the ISP end it will still on, thus the error message.

It may be possible when I first rebooted in Ubuntu, but how than it works in windows? After closing Windows and resatrted again on Ubuntu the same things happened.

[praka123]

ur lan card may be faulty(??) else,missing drivers.
what is ur lancard?
go through "lspci" output and post here.
most prolly it will be realtek made and runs on 8139cp kernel driver

[skghosh44]

Originally Posted by praka123

ur lan card may be faulty(??) else,missing drivers.
what is ur lancard?
go through "lspci" output and post here.
most prolly it will be realtek made and runs on 8139cp kernel driver

Lan card is not faulty. It is working fine in Ubuntu from Morning.
And in windows there is no any problem. ( GHOST is there in UBUNTU !!!!)