Re: Exim not accepting undescore in server name?

[Craig Sanders <cas@taz.net.au>]

On Tue, Jan 31, 2006 at 03:07:47AM -0500, Chris Wagner wrote:
> At 05:28 PM 1/31/2006 +1100, Craig Sanders wrote:
> >that's because in the early years, underscores WERE permitted in domain
> >names.
> >that changed somewhere around 1993 or 1994, IIRC.
> 
> Not to drag this thread out unnecessarily, but what low level thing is
> broken by having a _ in a domain name?

i dont know for sure. if i ever knew, i didnt care enough about it to remember.

something to do with old arpanet host naming conventions, i think.
alphanumeric and hyphen only.  probably nobody even thought of using
underscores in host/domain names until the net was accessible by the great
unwashed masses (i.e. the beginning of the eternal september).  my guess is
that underscores caused problems for arpanet hosts and users so they banned
them.  in other words, ancient historical stuff.  


also, IIRC, underscores are used in DNS service records.


craig

-- 
craig sanders <cas@taz.net.au>           (part time cyborg)