[Dnsmasq-discuss] Copying dnsmasq.leases, any issues to be aware of?

[Ed W]

Simon,

This is never going to get high enough up my todo list to try, but I did wonder if a simple
"clustered" system could be built using DBUS or similar events. When a lease is allocated DBUS (and
a script) is run notifying about that. A little daemon could then use this hook to notify another
instance of dnsmasq. In fact I think the hook is run synchronously? So it should be possible to ship
new leases across to the other instance

I can think of a number of ways this can be racy... However, for a little home lab it would surely
be good enough. I'm not sure how to handle failover, but a few simple ideas spring to mind (I'm
thinking of a pure warm standby kind of setup, where something promotes the secondary to primary)

Anyway, just shooting the breeze...

Ed W

On 05/02/2022 11:06, Simon Kelley wrote:
> It could work; there's a whole IETF standard for DHCP failover and it's implemented beautifully by
> ISC dhcp. If that's your niche, then ISC is the way to go.
>
> Simon.
> rent instances of dnsmasq on the
>> network
>>    - use UDP to 'copy' each new lease  to the other instance
>>    - on startup, use UDP to request a sync of known leases from the other instance
>>    - maybe sync local DNS entries as well (though it might be less desirable for folks
>>      like me who have 850k 'undefined' entries for ads, pron, warez, etc.)
>>
>> Could this even work? Would it be worth the effort?