Re: [cobalt-users] DNS Naming resolution - Raq Newbie

[Jeff Lasman <jblists@xxxxxxxxxxxxx>]

Chuck Gorish wrote:

> otherwise only the domain name and
> some virtual names are listed. i only list one name per ip addy, unless
> doing virtual domains.

You should never have reverse DNS point to more than one name.  I
generally use just the domain name, or a generic domain, i.e.,
"riverside1.nobaloney.net", "riverside2.nobaloney.net", etc., relating
to the fact that I have multiple entry points into the Riverside offices
of nobaloney.net.  If you need to do a reverse DNS entry (to speed up
mail and ftp logons, to speed up tracerouts, etc., but don't want to
identify your domain (for example, if you're a colocation company and
have promised your customers that no one will ever see your name even in
traceroutes, you can point reverse DNS to an IP#.  Against the rules,
but it works, as best I can tell, and preserves anonymity.

> actually, in review of the above, unless reverse is important for the raq
> machine name, i would make that a cname and make the www an actual A
> listing (and of course cnames dont get a ptr listing:)).

Actually, very few A records get a PTR record if you're doing virtual
name-based hosting; only one for each IP#.  PTR records are part of a
completely separate zone-file, though the RaQs seem to hide this fact
quite well.  They have nothing to do at all with what kind of records
you've used in your zone files for your domains.

In fact, most of us don't even have control over our reverse DNS; most
upstreams just don't delegate it unless we've got at least a C-block.

To see what I mean, try doing a reverse DNS lookup on a site you've been
running reverse DNS for, and see what you get.  I bet many of you will
get a generic listing for your colo company.

Jeff
-- 
Jeff Lasman <jblists@xxxxxxxxxxxxx>
nobaloney.net
P. O. Box 52672
Riverside, CA  92517
voice: (909) 787-8589  *  fax: (909) 782-0205