Change of FQDN

[Aaron Peterson]

On 7/18/05, Gary W. Swearingen <garys at opusnet.com> wrote:
> Aaron Peterson <dopplecoder at gmail.com> writes:
> 
> > hostname="www.mydomain.com"
> 
> Say I have two Ethernet ports and I'd like to be gary.mydomain.com on
> one and gary2.mydomain.com or gary.mydomain2.com on the other; then
> what?
> 
> A computer's domain name is set in several places -- not always the
> same values.  Most commonly they're in DNS servers and /etc/hosts and,
> of course, the computer's kernel as set by the "hostname" command (eg,
> using /etc/rc.conf's "hostname" variable).  But since there's only one
> "hostname" setting, which can't always match all the others, it's
> never made sense to me to set "hostname" to any public Internet domain
> name.  (And I never have, IIRC.)
> 
> And according to BCP-32, at http://www.rfc-editor.org/rfc/rfc2606.txt,
> "localhost" is the traditional top-level domain name "pointing to the
> loop back IP address" (which I think of as the 127/24 network), and it
> should be used to help keep broken DNS software from using any bogus
> domain on the Internet except well-known ones like "localhost".
> 
> Though the "hostname" command allows use of a top-level domain, other
> software doesn't (eg, "sendmail"), so it seems that a good domain is
> "something.localhost", where "something" may be "localhost", which
> might avoid some problems with broken software, or something more
> creative and maybe assigned uniquely to each of a group of computers.
> It is not used in the public (or maybe even a private) DNS system,
> except as an identifier for log files.
> 
> Am I missing something?  It's quite likely.  What other software
> than sendmail needs my single "hostname" and when?

Setting your public dns names on your dns servers and possibly in
/etc/hosts is probably a better option depending on your goals.  An
arbitrary hostname has been fine for me in all cases.  Do whatever
accomplishes your goals.

Aaron