[Dnsmasq-discuss] Secondary/tertiary dns servers in dhcp offers?

Simon Kelley simon@thekelleys.org.uk
Sun, 14 Nov 2004 17:18:14 +0000

Al Hooton wrote:
> Simon,
>> You could use teo indpendent instances as backups if they have 
>> identical copies of /etc/hosts and you wer'e using DHCP (see below 
>> about DHCP.)
>    OK, so here's a strange question (I'm sure this is a Bad Idea (tm) 
> for any number of reasons, some of which I think I can see, but I want 
> to get an expert opinion): What about using nfs to mount 
> /etc/resolve.conf  and the leases file from the primary on to the 
> secondary, and rely on nfs locking to keep accesses serialized?   Yes, I 
> realize there are issues that I'll have to address (other stuff in /etc, 
> known problems/races with nfslock, etc.). I'm just curious if anybody as 
> done something like this?

It would probably work fine. To be on the safe side, synchronise the 
clocks on the two machines using NTP or similar. (Though the code which 
checks for modifications to /etc/resolv.conf only looks for changes in 
the mtime on the file, so that probably won't matter.)
>> Each fits it's own niche though and I have to resist the temptation to 
>> grow dnsmasq until it becomes an unholy replication of the ISC daemons.
>    Yes, I  *completely* agree!  I've managed bind/dhcpd nets before, and 
> explicitly decided that I didn't want that pain for my small, 
> two-subnet, home network.  I'm not at all suggesting dnsmasq be made 
> more complex, that would be a mistake IMHO.  I'm just pushing at the 
> edges a bit, to see where they are.  I am *very* happy living within the 
> sensible boundaries of the dnsmasq system!
>    Thanks again for a great piece of code...

My pleasure.