atom feed4 messages in com.redhat.rhelv5-listRe: [rhelv5-list] Xen starting dnsmasq?
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Troels ArvinNov 25, 2007 2:47 pm 
Sadique PuthenNov 25, 2007 10:39 pm 
Sadique PuthenNov 25, 2007 10:43 pm 
Troels ArvinNov 25, 2007 11:48 pm 
Subject:Re: [rhelv5-list] Xen starting dnsmasq?
From:Sadique Puthen (sput@redhat.com)
Date:Nov 25, 2007 10:39:28 pm
List:com.redhat.rhelv5-list

Troels Arvin wrote:

Hello,

I generally try to minimize the number of daemons running on my servers, especially daemons listening on network sockets.

dnsmasq does not listen on your physical network sockets. It only listens on "virbr0" virtual interface that can NAT network connections from guests to Dom0. So anything except dom0 and guests can't access the service.

On a (dom0-)server set up for running paravirtualized Xen guests, I find that something starts dnsmasq after boot, even though the service has been turned off (with chkconfig).

It's libvirtd that starts dnsmasq.

I tried removing the dnsmasq package, but it seems to be required by the libvirt package (which I assume is rather important on a dom0 installation). Hence, my guess is that it's some Xen script/daemon which starts dnsmasq.

Turning off dnsmasq, and then restarting the xen guests doesn't seem to be a problem.

My questions:

- Under which circumstance(s) is dnsmasq important for running xen guests?

It's only required if you want to configure your guests in a private network and nat the packets to the outside network which is the preferred configuration for laptops.

- Can I somehow prevent xen from starting dnsmasq, now that a "chkconfig --level 345 dnsmasq off" doesn't help?

I am not aware of anything except a killall dnsmasq in rc.local, but dnsmasq is not listening on the public interface of dom0 for anything. It only listens on virbr0 and servers only the dns packets from guests.

--Sadique