[NCLUG] gethostbyaddr(x.x.200.6) failed: 1

[Michael Milligan]

Joshua SS Miller wrote:
> Hello all, 
> 
> A quick question how do I stop gethostbyaddr lookups on sendmail?  I
> have looked on the web, got out my sendmail book, and asked a few people
> but no one seems to know.  I am unable to add them to dns and would
> really rather not add them to /etc/hosts.  Is there any other way?
> 
> sendmail-8.11.6
> 
> Error is:
> 
> May 15 01:23:20 testmachine sendmail[27809]: gethostbyaddr(x.x.200.6)
> failed: 1
> May 15 01:23:21 testmachine sendmail[27828]: gethostbyaddr(x.x.203.25)
> failed: 2
> 

First off, Sendmail has been out of favor with me for a number of years, 
so I'm not sure on my first suggestion...  turn off the lookups.  But 
assuming that's not possible, about your only option (short of hacking 
the source of course) is to setup a local DNS server that Sendmail uses 
(via either it's resolve.conf or the global system one, i.e., 
"nameserver 127.0.0.1") which overrides these DNS reverse-mapping zones 
(200.x.x.in-addr.arpa and 203.x.x.in-addr.arpa) and provides whatever 
information you want to Sendmail.  And this server forwards all other 
queries to your original set of DNS servers.

If you want to do that, I'd be happy to help you with the exact 
configuration syntax.

Regards,
Mike

-- 
Michael Milligan  --  Free Agent  --  milli at acmeps.com