[Dnsmasq-discuss] Re: resolver options

[Simon Kelley]

AJ Weber wrote:
> 
> If I use a "different" resolv.conf file (i.e. I use a 
> resolv-file=/etc/resolv.dnsmasq), will an "option" have the same effect 
> it normally would?
>  
> For example, I'm considering changing timeout to 2 (instead of the 
> default of 5), because I've had some issues with my ISP's DNS servers 
> recently and don't want to wait too long for the timeout.  With the 
> broadband connection, any of the nameservers in my list consistenly 
> returns in < 1 sec (when they're up, of course).
>  
> Will this have the desired effect?  Any comments or concerns with that 
> change in general?  Am I misunderstanding the purpose of the "options 
> timeout:" ?

The only lines which are read by dnsmasq are "nameserver" ones - 
everything else is ignored, except "search" if the option --domain=# id 
used, when the first entry of the search string is used as dnsmasq's 
domain setting.

To get the effect of faster time-outs, it's necessary to alter the 
timeout in the clients, not in dnsmasq.
>  
> ALSO...(DIFFERENT TOPIC) : Is there no way to tell dnsmasq to dump it's 
> current lease-info to a file that could be read on restart so it knows 
> about all outstanding DHCP leases?  It's rare that I have to restart 
> dnsmasq or the linux box it's on, but when I do, it forces me to restart 
> a lot of client machines in case I'd get a dhcp/IP address mix-up (where 
> dnsmasq doesn't know an IP Address is already leased to a running 
> client, and a new client requests a lease so it hands-out the same 
> address).

Dnsmasq does this by default, in /var/lib/misc/dnsmasq.leases. You can 
change the location of the lease file using --dhcp-leasefile.

Cheers,

Simon.

>  
> Thanks in advance,
> AJ