[Dnsmasq-discuss] Unable to connect by hostname for local machines

[Dan Williams]

On Tue, 2012-10-23 at 06:49 -0600, dnsmasq at ailsby.net wrote:
> On 12-10-22 10:32 PM, /dev/rob0 wrote:
> > On Mon, Oct 22, 2012 at 09:24:34PM -0600, dnsmasq at ailsby.net wrote:
> >> I am trying to setup dnsmasq so that I can use the OpenDNS servers
> >> for my younger children, and then have all other devices use a
> >> different dns server (Google's).
> >>
> >> The program that I am having is that I cannot use the hostname of
> >> any of my local devices to connect, I can only do it via the ip
> > Neither Google nor OpenDNS knows the names and addresses of your
> > internal hosts. If you are setting your machines to use these
> > external nameservers, you're not using the DNS feature of dnsmasq.
> >
> >> address. This happens with my ubuntu server, and osx machines.  My
> >> windows laptop does not have an issue, and can ping other devices
> >> by hostname.
> >>
> >> As far as I can tell, all else is working properly.  The devices
> >> that are supposed to use OpenDNS are, and the ones that should use
> >> google's dns are.
> >>
> >> My setup:
> >> * tomatousb on my router
> >> * dnsmasq is version 2.61
> >> * static dns set to the OpenDNS ips
> >> * static ips assigned to the machines I want to use the google dns servers
> >> * dynamic ips assigned to the machines to use the OpenDNS servers.
> >> Set to the range of 192.168.1.100 to 192.168.1.199
> > A style suggestion: I would use CIDR-style ranges rather than
> > decimal-style. For example, 192.168.1.128-196 can be addressed in a
> > single CIDR expression, 192.168.1.128/26.
> >
> >> Options set for dnsmasq:
> >> # Range of IPs that are set up as static (computers that should
> >> have unrestricted DNS)
> >>
> >> dhcp-range=set:green,192.168.1.10,192.168.1.99
> >>
> >> dhcp-option=net:green, 3, 192.168.1.1 #Assigns "green" gateway to
> >> these clients
> >> dhcp-option=net:green, 6, 8.8.8.8 #Assigns "green'" DNS server to
> >> these clients (google).
> >>
> >> Any ideas on what I need to do so that the devices in the ip range
> >> 192.168.1.10 to 192.168.1.99 can use hostnames to connect to each
> >> other?  Is there any other information that is needed to understand
> >> this issue?
> > Probably what you want to do is to use a different upstream server
> > for the big people and little people machines. And I know of no
> > trivial way to do that in a single instance of dnsmasq. It might
> > require two instances (one of them being DNS-only.) And I'm not sure
> > that would be easy, either.
> >
> > This could be done with BIND named using views (and there too, you
> > would benefit from the above CIDR suggestion.) But then you wouldn't
> > have the ease of setup of dynamic DNS that dnsmasq offers.
> Thanks for the clear response.  I will have to see if there is some 
> other way to get to my desired end point.

Another possibility: avahi/zeroconf/bonjour/mDNS, which is precisely the
situation those were made for.  Run avahi-daemon on all machines and
then install the 'nss-mdns' glibc resolver plugin, and magically all
your machines are available via "<hostname>.local".  So if you have one
machine named "foo" and another named "bar", both are accessible on the
local network as foo.local and bar.local.

All this works completely outside normal DNS, exactly as it was meant
to, because (a) it's supposed to be easily done without central
administration, and (b) it's all local-network specific, so you don't
need to change anything about your DNS config, which you probably can't
do anyway because your upstream nameservers aren't under your control.

Dan