Karl Auer kauer at
Wed Oct 8 23:03:30 UTC 2008

On Wed, 2008-10-08 at 11:06 -0700, NoOp wrote:
> /etc/resolv.conf _absolutely_ gets written to by the network manager
> when using "Roaming" as you can see from the above. That is how
> "Roaming" mode works. As Leonard has shown, it's easy to demontrate this:

I think NetworkManager may indeed write to /etc/resolv.conf. In saying
"NEVER", Derek was a bit too enthusiastic. On the other hand, I have
been unable (and I have *looked*, quite hard) to find out what it *does*

It might write the comment at the top. I'm pretty sure it does, in fact,
but not 100% sure. To actually look at the code would be verging on the
obsessive, so I'm not going to do that :-)

I AM sure that dhclient does not write those lines. Everything dhclient
does is there for all to see in /sbin/dhclient-script.

> 1. Open NM and remove any existing DNS entries except for the router
> gateway (leave the NM dialog open for all of the following).

You may be making the same mistake I did - treating the Network Settings
dialogue as part of Network Manager. It's not, it's a separate program,
that NM will obligingly start for you if you select "Manual
configuration". You can get the same program via System ->
Administration -> Network. Aside from that convenience, there is no
connection between the two. Network Settings is basically a friendly way
to modifying /etc/hosts, /etc/resolv.conf and /etc/network/interfaces.

> It's too bad that other processes (dhclient, openvpn etc) don't write in
> the "Modified by" as NetworkManger does.

Indeed! This discussion might have been a lot shorter.

One possibility here is that dhclient *and* Network Manager BOTH update
resolv.conf. It's a bit hard to keep them apart though. I suppose I
could put a big delay in dhclient-script and see what's there after
dhclient has run but before control returns to Network Manager.

Regards, K.

Karl Auer (kauer at                   +61-2-64957160 (h)                  +61-428-957160 (mob)

GPG fingerprint: DD23 0DF3 2260 3060 7FEC 5CA8 1AF6 D9E3 CFEE 6B28

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