networking help

[frostyllama]

on my first installation after a few bumps in the road i was able to connect to my wireless network succesfully. all of a sudden on my second day using linux it coped out on me, i even re-installed it from scratch. i know its not the network because i am using a second computer on it now(windows). Whilst in the root acount when i try to enable the wireless connection after a split second it switches right back to disabled, i am almost certain that everything is configured properly.
thanks in advance

[askrieger]

Re: networking help

I'm sure that this question, or one very much like it was asked and answered by someone who knows about wireless within the last 24 hours. Of course, since I DON'T use wireless, I've forgotten the answer. >

[Nirvana]

Re: networking help

on my first installation after a few bumps in the road i was able to connect to my wireless network succesfully. all of a sudden on my second day using linux it coped out on me, i even re-installed it from scratch. i know its not the network because i am using a second computer on it now(windows). Whilst in the root acount when i try to enable the wireless connection after a split second it switches right back to disabled, i am almost certain that everything is configured properly.
thanks in advance

ndiswrapper: Some wireless LAN vendors refuse to release hardware specifications or drivers for their products for operating systems other than Microsoft Windows. NdisWrapper makes it possible to use such hardware with Linux by means of a loadable kernel module that "wraps around" NDIS (Windows network driver API) drivers.

This package provides the source code for the NdisWrapper kernel module. The default Ubuntu kernel already provides the required modules. You might only need this package if you use a custom kernel.

Kernel source is required to compile this module.

howto: https://wiki.ubuntu.com/SetupNdiswra...ndiswrapper%29

Universe repository is needed, so make sure it is enabled, howto here: http://psychocats.net/linux/sources.php

[Guest]

Re: networking help

This is very similar to the problem I'm having. After I installed, the internet worked for a few days, but it crapped out on me earlier today and I have no idea why. I'm pretty sure everything is configured correctly, but the interfaces are down, and when I click to enable them, they don't seem to stay up for longer than a second. I'm really at a loss here. When I manually try to sudo ifup eth1, i get the error "no working lease in persistent database".

I'm at a loss for words, any and all help is greatly appreciated.

[askrieger]

Re: networking help

From the use of the word "lease" in the error message, I'm going to guess that you have a DHCP problem. Grossly oversimplified, DHCP = "Dynamic Host Configuration Protocol". When a variable number of computers on your home or office network are going to be connected to the internet at any time, you don't want some computer that's turned off sopping up an IP address. So, when you start your computer, a package called DHCP-client calls your router or cable modem and says "Help, I want to talk to the internet." The DHCP server says, "Okay, you're 192.169.1.102 for the next 36 hours." That's called a dhcp lease. Hence my conjecture that your problem involves dhcp.

How does your computer know to ask for a dhcp lease? There is a configuration file called /etc/network/interfaces that has an entry for each of your possible network interfaces. The entry tells your computer whether a particular network adapter has a "static" IP address or whether it needs to use "dhcp". Look for a line in your /etc/network/interfaces file that says "iface eth1 inet XXXX", where XXXX is either "static" or "dhcp". In either case, I'm guessing that the problem is in there. Another way to check, without restarting your computer is to start a konsole in KDE and type "ifconfig -a". You will get a several lines of printout for each of the network interfaces on your computer. You will have at least 3, lo (which we won't go into here) eth0, and eth1. For the eth# interfaces look for a line saying something like "inet addr 192.168.1.100" If you don't find it it means that that interface isn't talking to the internet.

If in fact, I'm talking to a member of IETF who has written 37 RFC's typing with his elbows, I apologize for talking down, I'm addressing some new user who might have come upon this post by searching the forum.

[noridlo]

Re: networking help

Askrieger,

I'm a new user searching the forum. Thanks for the crystal clear explaination of DHCP and how to look for network status.

[askrieger]

Re: networking help

I suddenly realized that I had left out the way to renew your dhcp lease, if it has run out and not renewed itself automatically. Type the following sequence of commands at the konsole:

"sudo ifdown {name of interface}"
"sudo ifup {name of interface}" where {name of interface} means eth0 or eth1 or whatever. The problem is that the -a flag only works for interfaces that are listed as "auto" in /etc/network/interfaces.

I'm not even sure that need to run these as root, but it can't hurt (that's the beauty of sudo).