ubuntu-20.04 ignores domain name setting from DHCP (option 15)

[Josef Wolf]

On Mon, Aug 30, 2021 at 11:25:37AM +0200, Liam Proven wrote:
> On Mon, 30 Aug 2021 at 11:16, Josef Wolf <jw at raven.inka.de> wrote:
> >
> > > This is about setting up a DHCP server. The server is running and is happily
> > > sending the domain name. Problem is, that the clients simply ignore the domain
> > > name setting that the server is sending.
> >
> > No help with this problem?
> 
> I had another look.

Thanks for your answer, Liam!

> I think (suspect, not know for sure) that this may be because of the
> suffix: .lan is special and may be treated as reserved by some tools.
> 
> https://serverfault.com/questions/17255/top-level-domain-domain-suffix-for-private-network

No. .local is special. This is why Appendix G of rfc6762 suggests to use .lan
(or one of the other lsted alternatives) instead of .local.

In fact: at work we have an officially registered .xxxxx.com which also don't
work. Same thing with .xxxxx.de

Anyhow: the client should NEVER ignore what the DHCP server tells him. The
client is not in the position to know which domains are officially registered
and which not. It has to ask the DNS-Server (which usually is also set by the
DHCP server).

That's the whole point why a DHCP server exists: to tell how to set up the
network config.

> My home LAN used to be called .local until this became _meaningful_
> and stuff randomly stopped working.
> 
> https://en.wikipedia.org/wiki/.local

Well, that's a different point. Apple needs to be blamed for this. But please
note: .lan is not .local

-- 
Josef Wolf
jw at raven.inka.de