[SOLVED] Network stopped for no reason

[Mogweh]

Last night my computer worked fine, and this morning the network has stopped working.

I have installed nothing new, so am a little unsure why this has happened.

I'm using:

Asus M4A785D-M PRO motherboard
AMD Phenom II X4 945 CPU

Kubuntu 10.04


What I have tried:

When I plug the network cable into the router the light comes on. I tested another functioning cable from another computer and it won't work. I have access to the router from another computer but not this one. Pinging the router doesn't respond.

The following commands and files give:

ifconfig

eth0 Link encap:Ethernet HWaddr 45:e6:ba:51:b3:e2
inet addr:192.168.0.3 Bcast:192.168.0.255 Mask:255.255.255.0
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
Interrupt:26 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:74 errors:0 dropped:0 overruns:0 frame:0
TX packets:74 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:4950 (4.9 KB) TX bytes:4950 (4.9 KB)

lspci

02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 03)

resolv.conf

nameserver 192.168.0.1

interfaces

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
iface eth0 inet static
address 192.168.0.3
netmask 255.255.255.0
network 192.168.0.0
broadcast 192.168.0.255
gateway 192.168.0.1

Please advise, thanks

[toad]

Re: Network stopped for no reason (that I can see)

Hm, wait for Detonator

But seriously, your resolve.conf looks okay, ip addresses appear to be consistent and your interfaces looks okay as well You said you tried a different cable, so all I can think of is hardware/BIOS probs. Just to check, when was your interfaces last changed?

You could also try dhcp for completeness' sake. Apart from that I'd try out a live CD and see whether you can ping from that one (to double check the hardware/BIOS situation).

Anyway, some detective work for you to get on with ...

[Mogweh]

Re: Network stopped for no reason (that I can see)

I haven't changed anything for a long time. Everything on my network is Static IP as it has been for years.

I tried pining the router from the live CD but is returned "Network unreachable". However, I also tried it from a working computer and it returned the same. I guess I'd need to configure it, but I don't know how.

Is there a hard fast method of testing the hardware?

[Snowhog]

Re: Network stopped for no reason [Unsolved]

If you can't even ping your router - even from a 'working' PC - then I would say that your routers configurations have changed -- likely to the defaults? Prior to this issue appearing, did you have any power failures and/or "brown outs"? I would be accessing the routers configuration setting and verifying that the settings are as you want/need them.

[Mogweh]

Re: Network stopped for no reason [Unsolved]

Working PC's all connect fine.

I mean't that I tried loading the Live CD then pinging the router and it didn't work. Neither did it work on a working PC. So, I assumed I needed to do some further config (with the Live CD) that was beyond me.

The router works just fine.

[mhumm2]

Re: Network stopped for no reason [Unsolved]

Hi; the same thing happened to me. From this forum, I got an answer that solved my problem.

If I recall, it's a problem with the NetworkManager. There's a file in your system that ends with "state" and you have to delete that file. Once I deleted it, everything worked fine.

Found it...

rm /var/lib/NetworkManager/NetworkManager.state

I got this from another post: http://kubuntuforums.net/forums/inde...6853#msg226853

Hope this helps.

[Detonate]

Re: Network stopped for no reason [Unsolved]

This is a problem has has to do with a bug when resuming from hibernation. It may reoccur. Two easy fixes, disable hibernation, or remove network manager.

[Mogweh]

Re: Network stopped for no reason [Unsolved]

Cheers, I tried that earlier, unfortunatly it didn't work.

ran:

sudo apt-get remove network-manager-kde

sudo apt-get remove network-manager

[Detonate]

Re: Network stopped for no reason [Unsolved]

OK, try this.

sudo ifdown eth0

sudo ifup --force eth0

sudo start networking

[Mogweh]

Re: Network stopped for no reason [Unsolved]

How embarrasing. I actually turned off my computer and then switched off the PSU for a couple of minutes. When I restarted the network reappeared.

Not sure why.

Thanks to everyone who took the time to post some help.

[GreyGeek]

Re: [SOLVED] Network stopped for no reason

The resolv.conf file usually has your ISP domain name in it along with their DNS IP addresses.

Yours has "192.168.0.1", which is not right. The 192.*.*.* addresses are for LANs and cannot be seen by or see the Internet.

http://kubuntuforums.net/forums/inde...opic=3110183.0
[quote]
Wicd, Knetworkmanager, netapplet, knm-runtime, etc...
Lucid came with knm-runtime and some knetworkmanager guis and stuff installed. They immediately found my wireless and had no problem connecting. But, I wanted to switch to Wicd so that my wireless connected before kdm started up, so if the desktop crashed I still had access to the web without going through a cli connection hassle. The last time i switched to wicd, Synaptic automatically downloaded wicd, then removed knetworkmanager, and then installed wicd and reestablished a wireless connection. It appeared to do the same under Lucid but upon examination I found that wicd was using knm components! Removing ALL of the knm components resulted in wicd's config screen not being able to set up a WPA connection! I ended up having to remove every library related to knm and wicd itself. Reboot. Plug in an eth0 cable, run Synaptic and install wicd only. The gave me only wicd with WPA settings capability.

Completely removed the following packages:
modemmanager
network-manager
network-manager-openconnect
network-manager-openvpn
network-manager-pptp
network-manager-vpnc
knm-runtime
network-manager-kde
plasma-widget-networkmanagement

and

Installed the following packages:
python-urwid (0.9.9.1-1)
python-wicd (1.7.0-2)
wicd (1.7.0-2)
wicd-cli (1.7.0-2)
wicd-curses (1.7.0-2)
wicd-daemon (1.7.0-2)
wicd-gtk (1.7.0-2)

[skunk]

Re: [SOLVED] Network stopped for no reason

The resolv.conf file usually has your ISP domain name in it along with their DNS IP addresses.

Yours has "192.168.0.1", which is not right. The 192.*.*.* addresses are for LANs and cannot be seen by or see the Internet.

Unless your router is supplying DNS for your subnet

[Detonate]

Re: [SOLVED] Network stopped for no reason

That's true. But it does not seem to work if using a static IP unless you specify the DNS servers in the resolv.conf file. I always enter the same DNS servers in both my router and in the resolv.conf file. DHCP on the other hand, will automatically populate the resolv.conf file with the DNS servers listed in the router.

[GreyGeek]

Re: [SOLVED] Network stopped for no reason

Right.
If dhcp doesn't automatically populate resolv.conf with the ISP DNS addresses then something is broken.
IF a static IP address and static DNS (which is usually the case) is chosen then it is up to the user to populate the necessary info in the manager properties table.

[Detonate]

Re: [SOLVED] Network stopped for no reason

Or, as I prefer. by directly editing the resolv.conf file if you don't use the network manger.