[Dnsmasq-discuss] Documented Redundancy?

[Gui Iribarren]

On 31/07/14 13:23, Simon Kelley wrote:
> On 30/07/14 07:35, Joel Krauska wrote:
>> I've seen a few interesting proposals for running dnsmasq in a redundant
>> way.
>> (running active/passive and trying to keep leases updated atomically, eg.
>> using a db)
>>
>> But I haven't seen an actual implementation documented anywhere.
>>
>> Those concepts mostly 'address' setting up a standby dhcp server, but I'm
>> also interested in a secondary DNS server implementation using dnsmasq, and
>> I can't seem to find detailed documentation on that either.
>>
>> Just in case anyone is wondering 'why' -- machines need package updates and
>> occasional rebooting.  I'd very much like to be able to temporarily take
>> down my primary dhcp/dns infra with minimal impact.
>>
>> I've used isc and bind, and frankly it's a PITA to manage and maintain.
>>
>> I really like the simplicity of dnsmasq, but I'd also like some manageable
>> redundancy?
>>
>> Is there a blog post out there that I just can't seem to find?  :)
>>
>> If not, I guess I'll have to try to make one myself.
>>
>> Cheers,
>>
>> Joel Krauska
> 
> I'm not aware of anybody having done this and documented it. 

We are working on the idea, and have made progress, but don't have it
100% working yet,
and definitely not documented it

if anyone wants to dig into the ongoing development,
https://github.com/libre-mesh/lime-packages/tree/master/packages/dnsmasq-lease-share

> The insight
> that you don't really need redundancy for DHCP, only DNS is a valid one.

Our scenario is actually more like "master to master" sincronization:
two or more active DHCP servers on the same (pseudo)link-local.

This specific need might only make sense in batman-adv mesh networks,
but i guess it could be adapted to the master/slave case the OP is
asking about

Cheers!



> Maybe it would work to have a secondary dnsmasq configured only for DNS,
> and make the primary maintain a file in /etc/hosts file format with the
> DHCP hosts and their addresses. The DHCP script is provided with enough
> information to maintain a complete lease database, so just the
> names/addresses would be quite possible. Moving that file from master to
> slave left as an exercise for the reader :)
> 
> Cheers,
> 
> Simon.
> 
> 
> 
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