First of all, dom in our world is an FQDN. That means that both
.home.davidashen.net and .davidachen.net are wrong.

We ask dhcp for a hostname and a domain.  For the latter, dhcp's
seem to differ in what they give back, i.e., the FQDN of the machine,
the FQDN domain name that the machine is in, or that FQDN starting
with a '.'.    Ipconfig tries to deal with the situation, clearly
not well enough.  I'll try to do better but, if the server doesn't
return the hostname, its hard to guess.  the dom=.davidashen.net 
clearly indicates that we only got the domain and not the hostname.
This is a effect of the spread of windows where the hostname is
always in local storage and diskless boot is not really considered.

I'll try to do better in ipconfig.