From owner-freebsd-questions@freebsd.org Fri Aug 3 21:41:50 2018 Return-Path: Delivered-To: freebsd-questions@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 2DE46105258D for ; Fri, 3 Aug 2018 21:41:50 +0000 (UTC) (envelope-from galtsev@kicp.uchicago.edu) Received: from kicp.uchicago.edu (kicp.uchicago.edu [128.135.20.70]) by mx1.freebsd.org (Postfix) with ESMTP id D7A9E76CD4 for ; Fri, 3 Aug 2018 21:41:49 +0000 (UTC) (envelope-from galtsev@kicp.uchicago.edu) Received: from point.uchicago.edu (point.uchicago.edu [128.135.52.6]) by kicp.uchicago.edu (Postfix) with ESMTP id 1BCE77180AA for ; Fri, 3 Aug 2018 16:41:43 -0500 (CDT) To: FreeBSD Mailing List From: Valeri Galtsev Subject: name resolution puzzle Message-ID: <5cbb1cc0-8e3f-2736-755e-d182abfd90e6@kicp.uchicago.edu> Date: Fri, 3 Aug 2018 16:41:42 -0500 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.27 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 03 Aug 2018 21:41:50 -0000 Dear Experts, I just noticed some behavior of commands "host" and "nslookup" that puzzles me. Namely, they do not query /etc/hosts file first, but query nameserver instead, even though nsswitch.conf order is "files dns": $cat /etc/nsswitch.conf | grep hosts hosts: files dns $ cat /etc/hosts | grep holometer.uchicago.edu 128.135.20.84 holometer holometer.uchicago.edu $ host holometer.uchicago.edu holometer.uchicago.edu has address 128.135.52.70 $ nslookup holometer.uchicago.edu Server: 128.135.249.50 Address: 128.135.249.50#53 Name: holometer.uchicago.edu Address: 128.135.52.70 So, it appears, that the commands "host" and "nslookup" go directly to DNS server, and do not look into /etc/hosts first which I have expected. I should mention that other compiled programs do obey the nsswitch.conf query order. Can someone enlighten me on this? The reason I have different IP in /etc/hosts is: I'm building the box to migrate some host to, and I'd like to test some stuff that should work from other machines before I switch DNS records to new IP. So, on these external machines I am trying to have hostname resolve into future IP just by adding it to /etc/hosts. Thanks. Valeri -- ++++++++++++++++++++++++++++++++++++++++ Valeri Galtsev Sr System Administrator Department of Astronomy and Astrophysics Kavli Institute for Cosmological Physics University of Chicago Phone: 773-702-4247 ++++++++++++++++++++++++++++++++++++++++