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Date:      Tue, 22 Sep 1998 20:03:24 -0400 (EDT)
From:      "Woodchuck"  <djv@bedford.net>
To:        dhw@whistle.com (David Wolfskill)
Cc:        FreeBSD-Questions@FreeBSD.ORG, jfrodo42@hotmail.com
Subject:   Re: "invalid hostname" on "last"
Message-ID:  <199809230003.UAA11322@lucy.bedford.net>
In-Reply-To: <199809221645.JAA15029@pau-amma.whistle.com> from David Wolfskill at "Sep 22, 98 09:45:59 am"

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David Wolfskill wrote:
> >From: "Jane Frodo" <jfrodo42@hotmail.com>
> >Date: Mon, 21 Sep 1998 17:21:17 PDT
> 
> >     We have a user who always shows "invalid hostname" when
> >we "last <username>".  The problem is it looks ok on nslookup!
> >One of the ip's you can look at is 209.63.23.76.  This IP has
> >no DNS errors I can _see_, but last _hates_ it!
> 
> >     What is last trying to tell me about this IP?
> 
> I suspect the following (from "man logwtmp"):
> 
> DESCRIPTION
>      The function logwtmp() tries to append a new record to the wtmp(5) file,
>      using the provided arguments line, name, and host, and the current time.
> 
>      If the length of the hostname string host is longer than what would fit
>      into the hostname field of the wtmp(5) file, it will first be attempted
>      to convert it into a numerical IP address using gethostbyname(3).  Fail-
>      ing this, the hostname will be recorded as "invalid hostname".
> 
> david


host 209.63.23.76 belongs to that strange class of hosts for which
a lame dns server has configured a reverse lookup, but no forward lookup,
so gethostbyname(3) will puke, as you point out.

from nslookup...

> set type=any
> 76.23.63.209.in-addr.arpa
Server:  localhost
Address:  127.0.0.1

Non-authoritative answer:
76.23.63.209.in-addr.arpa       name = ip76.castlenet.com

Authoritative answers can be found from:
23.63.209.in-addr.arpa  nameserver = screwtape.redrock.net
23.63.209.in-addr.arpa  nameserver = ns1.castlenet.com
screwtape.redrock.net   internet address = 209.63.22.2
ns1.castlenet.com       internet address = 209.63.23.2
> ip76.castlenet.com
Server:  localhost
Address:  127.0.0.1

*** localhost can't find ip76.castlenet.com: Non-existent host/domain
> 

So Jane needs to talk to the dns admins of screwtape.r.n and 
ns1.castlenet.com. They both appear hosed.

Dave
-- 
       Will hack for cabbages!  Every day is Groundhog Day!

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