Web lists-archives.com

Re: Can't find the DNS Servers




On Wed, Oct 04, 2017 at 01:30:21PM -0500, David Wright wrote:
> On Wed 04 Oct 2017 at 21:13:51 (+0300), Reco wrote:
> > On Wed, Oct 04, 2017 at 02:08:17PM -0400, Michael Stone wrote:
> > > On Wed, Oct 04, 2017 at 08:59:46PM +0300, Reco wrote:
> > > > On Wed, Oct 04, 2017 at 11:59:04AM -0500, David Wright wrote:
> > > > > On Wed 04 Oct 2017 at 09:11:37 (+0300), Reco wrote:
> > > > > > A correct way to fix this is to "persuade" your DHCP server not to
> > > > > > provide DNS information.
> > > > > > Even more correct way is to force your DNS-at-DHCP to use 8.8.8.8 as
> > > > > > forwarder DNS.
> > > > > > Since it's unnaturally complex to do so in a consumer-grade routers, a
> > > > > > hack is in order.
> > > > > 
> > > > > But won't that send local host lookups to google which won't have a clue?
> > > > 
> > > > Why won't it have a clue?
> > > 
> > > Because google doesn't know what names you use on your local network.
> > 
> > Once one starts using 8.8.8.8 - it will. Even it won't show it.
> > Friends don't let friends use Google resolvers.
> > A software that's using "Four Eights" by default was considered buggy in
> > Debian back in the day.
> 
> Can I just check that we're talking about the same thing? Are you
> saying that if I ask 8.8.8.8 for the IP address of wasp (that's its
> "FQDN") it will reply with 192.168.1.13?

No, it should answer NXDOMAIN.
But Google will remember that you have a host with this name.
It may even advertise you a wasp repellent one day.


> > > To
> > > implement local lookups you need a name server which can selectively either
> > > serve a local name or forward the request to an internet name server.
> 
> Just to be clear, I'm using "local" in the everyday meaning, not in
> the sense of .local in whichever RFC it is.

Other than being a violation of RFC 6762 (and the thing Microsoft
suggests) that's probably OK.


> > > That
> > > can't be done in resolv.conf, but can be done either centrally or locally
> > > via unbound or similar.
> > 
> > Or, /etc/hosts. For a simple household network how hard could it be?
> 
> I was under the impression that the OP had a DNS-serving router which
> could perform that job successfully (a) before setting up qemu-kvm

"apt install qemu-kvm" could not lead to this result.
Even with "apt install libvirt-daemon-system" it's impossible.

Installing these packages *and* implementing a howto or two from random
Internet sites - that's definitely possible.


> and (b) still worked for whatever a qemu-kvm is but not for the
> actual ?host machine.

By default libvirt creates "virbr0" bridge and starts dnsmasq (if it's
installed) to serve DNS and DHCP requests coming from "domains" (aka
virtual machines). So yes, *some* DNS requests from inside virbr0 should
work.

Reco