Re: How to make NM call dnsmsaq with --bind-dynamic ?

[Dan Williams <dcbw redhat com>]

On Mon, 2015-09-14 at 23:25 +0200, Jean-Christian de Rivaz wrote:
> Hello,
>
> I use NetworkManager on a embedded Debian Jessie system that have 
> multiples interfaces, some of them going up dynamically. The system is 
> acting as a router between the interfaces and have the relevant iptables 
> rules to do NAT masquerading and MSSTCP handling. The only remaining 
> point is to have a DNS server on the system accessibly from any 
> interface at any time. To do that I have added the 
> /etc/NetworkManager/dnsmasq.d/interface file with this content:
>
> interface=*
>
> It do the expected work, but only until the interface list change: At 
> this point dnsmasq will not bind new interfaces. According to the 
> dnsmasq manual there is a --bind-dynamic to handle this.
> Unfortunately NM call dnsmasq with the --bind-interfaces option that is 
> incompatible with the --bind-dynamic option. And NM don't restart 
> dnsmasq when the interfaces list change.

I'll assume you're talking about the local caching nameserver stuff
here, not about the internet connection sharing.  Both use dnsmasq, but
in different ways.

It sounds like you're trying to use NM's dnsmasq functionality in a way
that isn't really intended; it's not supposed to be a DNS server for all
other machines on any interface, it's simply supposed to be a local
caching nameserver for the *local*  machine.  If you want a generic
forwarder for all machines, you would typically configure a separate
dnsmasq service that would read its DNS servers from /etc/resolv.conf
and watch that file for changes.  NM itself wouldn't be set up with
local caching nameserver functionality though.

Dan