From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 13537 invoked by alias); 14 Mar 2010 05:39:45 -0000 Received: (qmail 13302 invoked by uid 22791); 14 Mar 2010 05:39:44 -0000 X-SWARE-Spam-Status: No, hits=-3.2 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_LOW X-Spam-Check-By: sourceware.org Received: from out1.smtp.messagingengine.com (HELO out1.smtp.messagingengine.com) (66.111.4.25) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Sun, 14 Mar 2010 05:39:39 +0000 Received: from compute2.internal (compute2 [10.202.2.42]) by gateway1.messagingengine.com (Postfix) with ESMTP id 7BD32E512A for ; Sun, 14 Mar 2010 00:39:37 -0500 (EST) Received: from heartbeat1.messagingengine.com ([10.202.2.160]) by compute2.internal (MEProxy); Sun, 14 Mar 2010 00:39:37 -0500 Received: from [192.168.1.3] (user-0c6sbd2.cable.mindspring.com [24.110.45.162]) by mail.messagingengine.com (Postfix) with ESMTPSA id 22EC44ADB9D; Sun, 14 Mar 2010 00:39:37 -0500 (EST) Message-ID: <4B9C7690.1040906@cwilson.fastmail.fm> Date: Sun, 14 Mar 2010 05:39:00 -0000 From: Charles Wilson User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.8.1.23) Gecko/20090812 Thunderbird/2.0.0.23 Mnenhy/0.7.6.666 MIME-Version: 1.0 To: Talk Amongst Yourselves Subject: Bah! multicast dns == pain Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Mailing-List: contact cygwin-talk-help@cygwin.com; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: cygwin-talk-owner@cygwin.com Reply-To: The Vulgar and Unprofessional Cygwin-Talk List Mail-Followup-To: cygwin-talk@cygwin.com X-SW-Source: 2010-q1/txt/msg00077.txt.bz2 I've been trying to update the inetutils packages to upstream 1.7, but it's been difficult; the servers were not cooperating. I finally decided to AT LEAST see if the clients were working. However, since I didn't have any local working servers...I had to set up telnetd/rshd and friends on the linux box. Meanwhile, I had (finally) updated my linux box installation to a recent distro. And...stuff didn't work. I thought. Then, I noticed that it kinda did work, only it was VERY VERY slow. e.g. 'rsh linuxbox', wait 30 seconds, then login succeeds. Well, that's typically indicative that DNS is borked (esp. reverse lookups). But...on both boxes, nslookup and nslookup worked instantly. So, several hours of wireshark and strace later -- and a few red herrings involving an ident server on my windows box (*) -- I discovered a number of 5 second timeouts associated with RESOLVE-HOSTNAME-IPV4 write(3, "RESOLVE-HOSTNAME-IPV4 ... read(3, "-15 TIMEOUT ... Hmm...funny, a lot of those google hits for RESOLVE-HOSTNAME-IPV4 mention nis settings with 'mdns'. What's that? Oh, some multicast DNS thing for zero-conf network auto configuration. Hmm...it's related to NSS: /etc/nsswitch.conf contains: hosts: mdns4_minimal files nis dns mdns4 But why would THAT be a problem? This whole 'multicast DNS' thing is supposed to make things work better when you DON'T have a DNS server -- not screw things up when you DO have a properly configured one! But wait! What does this one google hit say about mdns? '...mdns is authoritative for .local?' Hmm?? ...ah, wiki: http://en.wikipedia.org/wiki/.local "local is a pseudo-top-level domain used in multicast domain name service (mDNS) of zero configuration networking discovery protocols." Crap. For ten years I've been using ..local for my private network. But now this mdns4_minimal thing is being queried FIRST, and it ignores everything BUT .local. However, seeing a .local, it tries to contact that device, and...times out. OK, let's log on to the DNS server and change that to .private. Reset hostnames everywhere, poke, prod, cajole, cry (oops, forgot to change /var/yp/ypservers), poke again...and try rsh One. More. Time. and instantly... rsh linuxbox Last login: Sat Mar 13 23:41:31 from windowsbox [me@linuxbox ~]$ I hate mdns. (*) actually, not so much of a red herring after all. It appears that I DO need the identd server running, or there is ANOTHER source of delay/timeout. I don't remember my old linux rsh server doing this, but...the new one sure does. More research needed. -- Chuck