Re: domain name

[Glenn English <ghe@slsware.com>]

On Sep 1, 2012, at 3:15 PM, John Hasler wrote:

> The kernel has no interest in domain names.  It deals only in IP
> numbers.  Dealing with DNS is the job of a resolver running in user
> space.

Thanks. I didn't know that -- makes sense. But it raises a question in 
my mind: Who does, beside servers? Just 'hostname'? 

I think I came into the TCP/IP networking business a little late. Was 
there ever a time when there were no domains, just IPs? That could 
explain a lot to me about why the domain name is so hard to get to...

> A machine can be in more than one domain.

I don't understand that. I've got several domains' nameserver records 
pointed at my server, serving a number of protocols. But the server 
itself is in only one domain. Apache and Postfix and Bind all handle the 
different domains, but I think of all of them as virtual domains, not the 
one true domain that my server is part of. 

Am I thinking wrong? Or is it possible somehow for a machine to have 2 FQDNs? 
I've never considered that. And I can't think of how to configure things so 
'hostname --fqdn' could answer with 2 strings...

-- 
Glenn English