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! To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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