Re: [cobalt-users] gethostbyaddr ???

["Steve Werby" <steve-lists@xxxxxxxxxxxx>]

"Goetz Lohmann" <goetz.lohmann@xxxxxx> wrote:
> >I want to know what this is... :
> >
> >Feb 12 12:07:46 raq sendmail[18747]: gethostbyaddr(m.y.I.P) failed: 1
> >
> >My logcheck send me hundreds like that every day, but that server is not
so
> >much used.... !?
>
> sendmail try to resolve the hostname and failed this happens most
> if no reverse lookup is possible (DNS) ... maybe change this in
> your DNS settings or maybe try to add the IP to
>
> /etc/hosts
> 127.0.0.1         localhost
> 123.123.123.123   my.domain.com
>
> or just ignore it ;-)

Don't ignore it.  Unless you have a class C subnet and your upstream
provider has delegated reverse DNS management to you, it's likely you can't
setup proper reverse DNS records yourself.  Less than 5% of my clients have
been delegated reverse DNS management so it's likely you haven't either.
Though you can have many virtual hosts on a single IP, you can only have one
reverse DNS record (maps an IP to a single hostname).  Technically it
doesn't even have to be a host on that IP (one with a forward record to that
IP), but that's generally a good idea.  Ask your upstream provider to setup
reverse DNS records for *all* of your IP addresses.

--
Steve Werby
President, Befriend Internet Services LLC
http://www.befriend.com/