FC3 DNS problem

Place to discuss Fedora and/or Red Hat
Post Reply
caveman
programmer
programmer
Posts: 130
Joined: Sun Feb 09, 2003 1:08 pm
Location: Midrand Gauteng, South Africa

FC3 DNS problem

Post by caveman » Mon Feb 07, 2005 4:42 pm

hi.

I have a strange problem that started after upgrading to the 741 kernel.
I've never had problems with my network connections...
My development machine runs FC3 and my internet gateway is on FC1.

On my development machine after upgrading to 741 I discovered that
my /etc/resolv.conf is allways empty when I reboot. This means no
connection to the Internet and a "netstat -r" only shows the std defaults.

<quip>
why do I reboot? - this is the electric storm season on the highveld
in South Africa and it is heavy stuff! Where I stay is apparently one
of the most severe lightning areas in the world!
</quip>

Two ways to overcome this
a) (not good at all) - edit the resolv.conf file and add the needed entries.
b) Start the network GUI, edit any of the DNS entries - this to force an
update - then stop and restart the network. This then fills the resolv.conf
file and a "netstat -r" then have the correct entries.

I have upgraded to the 760 kernel over the weekend - and the problem is
still there.
So the questions.....
a) Have I by accident changed something?
b) Anybody else had this happen?
c) Any ideas to resolv (sic) this?

User avatar
Void Main
Site Admin
Site Admin
Posts: 5716
Joined: Wed Jan 08, 2003 5:24 am
Location: Tuxville, USA
Contact:

Post by Void Main » Mon Feb 07, 2005 5:52 pm

Yes, I have seen a few people complain of this on fedoraforum.org. Here is one example along with what appears to be a solution in the last post:

http://fedoraforum.org/forum/showthread.php?t=32157

I can think of a few other possible solutions. The first one that comes to mind is to use a static /etc/resolv.conf (uncheck "Automatically obtain DNS information from provider" in the configuration of your interface in system-config-network).

caveman
programmer
programmer
Posts: 130
Joined: Sun Feb 09, 2003 1:08 pm
Location: Midrand Gauteng, South Africa

Post by caveman » Mon Feb 07, 2005 6:25 pm

Hmm TX - that was actually the first check that I made..
Made sure everything was "static" and nothing is resolved via dhcp etc.

I've never had "allow all users to activate....." set on my machines...
so I've now set it - saved - unset it and saved again.
Shall check this as soon as I get time to reboot and if needed check
the above and see if there is any difference.

Actually though of taking the write attribute away from root as well
on the resolv.conf file.... will try that as a last resort if need be ;)

User avatar
Void Main
Site Admin
Site Admin
Posts: 5716
Joined: Wed Jan 08, 2003 5:24 am
Location: Tuxville, USA
Contact:

Post by Void Main » Mon Feb 07, 2005 8:14 pm

What version of the initscripts package do you have installed? PEERDNS=no in your interface config file (unchecking the box I said) should make it so your resolv.conf is left untouched (see scripts in /etc/sysconfig/network-scripts).

caveman
programmer
programmer
Posts: 130
Joined: Sun Feb 09, 2003 1:08 pm
Location: Midrand Gauteng, South Africa

Post by caveman » Tue Feb 08, 2005 5:41 pm

The initscripts -> initscripts-7.93.5-1 from Nov 2004

And in the ifcfg-eth0 file -> PEERDNS=no
But
the ifcfg-mypppentry -> PEERDNS=yes on the server running FC1
I'll set this to "no" as well and test during the morning when I have
to reboot due to some electrical cables being installed.

Shall keep you informed as soon as I know what cooks.

caveman
programmer
programmer
Posts: 130
Joined: Sun Feb 09, 2003 1:08 pm
Location: Midrand Gauteng, South Africa

Post by caveman » Wed Feb 09, 2005 5:19 pm

Nope.

Tried all of that, as well as the suggestions on the fedora forums.
Rebooting -> the resolv.conf is empty.

Tried changing the permissions from 644 to 444 on the resolv.conf file
- but some scripts somewheres changed it back - and emptied the file :?

So for now - I have to remember to reset it everytime until a
solution is found. Shall have to "google" some more :roll:

Maybe I'll put a script into the rc.local until the problem is fixed.

User avatar
Void Main
Site Admin
Site Admin
Posts: 5716
Joined: Wed Jan 08, 2003 5:24 am
Location: Tuxville, USA
Contact:

Post by Void Main » Wed Feb 09, 2005 6:23 pm

Yeah, you could create a /etc/resolv.conf.caveman and add "cp -f /etc/resolv.conf.caveman /etc/resolv.conf" in your rc.local. For completely different reasons on my laptop I created a "/sbin/ifup-local" script that among other things copies /etc/resolv.conf.work /etc/resolv.conf. After an interface is activated the /sbin/ifup-local is executed if it exists (doesn't exist until you create it). The first argument passed is the interface name (eth0, eth1, ath0, etc). Obviously I have different resolv.conf settings whether I am at home or at work and I use a different network interface at home than at work so that script is a good place to do location specific things.

It's still very strange that this is happening though. If you go back to an older kernel does it continue to happen? I still can't imagine that it would be kernel related.

Post Reply