Why did I have to remove resolvconf to get dnsmasq to work again?

Solution 1:

The simple answer to (1) is: resolvconf sets itself up as the intermediary between programs that supply this information (such as ifup and ifdown, DHCP clients, the PPP daemon and local name servers) and programs that use this information (such as DNS caches and resolver libraries). As of Ubuntu 12.04 resolvconf is part of the default installation in both the server and desktop variants. It is never necessary to remove resolvconf and people who do remove it usually don't understand it, generally because they haven't read resolvconf(8) and /usr/share/doc/resolvconf/README.gz.

The answer to the second question is that resolvconf most probably did not interfere with dnsmasq. My guess is that you were running into bug #959037.

Explanation: In Ubuntu 12.04 there are two ways in which dnsmasq gets run. There is the traditional standalone version of dnsmasq which listens on all addresses. And there is the new NetworkManager-controlled dnsmasq process which listens only on 127.0.0.1. The latter conflicts with the former unless the former is reconfigured. This problem was solved in Ubuntu 12.10 by having the NM-controlled dnsmasq process listen on 127.0.1.1 instead of 127.0.0.1 and by forcing the standalone dnsmasq process to listen only on addresses assigned to interfaces.

Solution 2:

I've just removed it on my install. I was using pppd manually to dial my 3G modem connection and resolvconf interfered with my dns settings by automatically adding my provider DNS when I wanted to use custom DNS. pppd has options to control this but resolvconf clobbered them with its own settings. I would also like to know answer to this question? It seems like this is some make-it-easier-but-instead-complicate-things kind of package?

p.s. I've found this bug report: https://bugs.launchpad.net/ubuntu/+source/resolvconf/+bug/922578

Solution 3:

The simple answer to (1) is: resolvconf sets itself up as the intermediary between programs that supply this information (such as ifup and ifdown, DHCP clients, the PPP daemon and local name servers) and programs that use this information (such as DNS caches and resolver libraries).

That's from the package description. On desktops, it works in conjunction with NetworkManager to handle making and dropping connections smoothly.

So resolvconf, along with dnsmasq, are used in 12.04 to make the DNS info handling more reliable on the desktop version. So in some situations, it does make things better, but the whole situation lacks the documentation in the right place, esp. in the server world.

Despite loads of Googling, I haven't been able to ascertain what is recommended on a server installation.

As far as (2) goes, you're having the opposite problem from me. Dnsmasq works well with resolvconf on my machine and updates the /etc/resolv.conf file to contain 127.0.0.1 but has other problems because dnsmasq doesn't get the ISP name servers from dhclient on eth0 (this is a gateway) nor does it get the name servers I manually entered in the eth0 stanza in /etc/network/interfaces.

Why do you use dnsmasq? Are you also running a gateway with 2 nics? Or is it just a plain desktop? If so, resolvconf co-ordinates with network-manager