[Dnsmasq-discuss] Setting up dnsmasq on an [x]ubuntu machine - what's the 'right' way to do it?

[Simon Kelley]

On 10/05/14 17:07, Chris Green wrote:
> On Sat, May 10, 2014 at 12:07:59PM +0100, Chris Green wrote:
>> I've been using dnsmasq for quite a while on a small server machine on
>> my home network but that machine is now redundant really and I'd like
>> to save the electricity it's using.
>>
>> So I'm going to move dnsmasq to my desktop machine (which is also a
>> server and is powered up all the time).  My desktop machine runs
>> xubuntu 14.04 so has the default resolvconf setup where the resolver
>> runs a cut-down dnsmasq and /etc/resolv.conv just points to 127.0.0.1.
>>
>> What's the 'right' way to install a full dnsmasq onto my system and
>> make it use /etc/dnsmasq.conf for configuration etc.?  I know I had a
>> fairly hard time sorting it out on the system where it is now and I
>> want to make the process as painless as possible! :-)
>>
> Well I decided I could probably muddle through and I seem to have
> managed it fairly OK, I have attached my summary of how to do it (as a
> Dokuwiki text file, easy enough to read).  Would it be useful to add
> this to the FAQ, it's an issue that comes up quite a lot in various
> forums.

It would be good to put it somewhere. I'm not sure about the FAQ, which
is fairly distrubution-agnostic. Let me think about that.
> 
> It's not for the faint-hearted though, I'll make some comments here.
> 
> 
>> Obviously I need to give my machine a static IP on my Lan, that's easy
>> enough.
>>
> Yes, no need to set the DNS server(s) here, I don't think.
> 
> 
>> At present there is dnsmasq-base installed (used by resolvconf), if I
>> just install the dnsmasq package will it do the necessary so that 
>> it uses /etc/dnsmasq.conf etc.?
>>
> Yes, but you need to disable the NetworkManager dnsmasq by editing
> /etc/NetworkManager/NetworkManager.conf to remove the dns=dnsmasq.
> 
> 
>> Where do I specify the upstream DNS servers that dnsmasq should use?
>>
> In one or more files in /etc/NetworkManager/system-connections.
> 
> 
>> Can I get dnsmasq to hand out a secondary/backup DNS server to DHCP
>> clients so that if/when my desktop machine is turned off for upgrades
>> or reboots it doesn't totally disable the other machines on the LAN?
>>
> I still want an answer to this one please.

dhcp-option=option:dns-server,0.0.0.0,<ip of secondary DNS server>

That sends two addresses as DNS servers in DHCP replies: 0.0.0.0 is
replaced with the address of the machine running dnsmasq, and the second
is the secondary.


Cheers,


Simon.