From owner-freebsd-questions@FreeBSD.ORG Wed Mar 3 10:14:04 2004 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 0EFA216A4CF for ; Wed, 3 Mar 2004 10:14:04 -0800 (PST) Received: from smtpout.mac.com (A17-250-248-89.apple.com [17.250.248.89]) by mx1.FreeBSD.org (Postfix) with ESMTP id F065643D39 for ; Wed, 3 Mar 2004 10:14:03 -0800 (PST) (envelope-from cswiger@mac.com) Received: from mac.com (smtpin07-en2 [10.13.10.152]) by smtpout.mac.com (Xserve/MantshX 2.0) with ESMTP id i23IE2kn023804; Wed, 3 Mar 2004 10:14:02 -0800 (PST) Received: from [10.1.1.193] ([199.103.21.225]) (authenticated bits=0) by mac.com (Xserve/smtpin07/MantshX 3.0) with ESMTP id i23IE1gv014819; Wed, 3 Mar 2004 10:14:02 -0800 (PST) In-Reply-To: <200403031756.i23HuKB7052724@dc.cis.okstate.edu> References: <200403031756.i23HuKB7052724@dc.cis.okstate.edu> Mime-Version: 1.0 (Apple Message framework v612) Content-Type: text/plain; charset=US-ASCII; format=flowed Message-Id: <94EA94E2-6D3E-11D8-85AD-003065ABFD92@mac.com> Content-Transfer-Encoding: 7bit From: Charles Swiger Date: Wed, 3 Mar 2004 13:14:16 -0500 To: Martin McCormick X-Mailer: Apple Mail (2.612) cc: freebsd-questions@freebsd.org Subject: Re: Can Not ping Hosts by name when Underscores are Present. X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 03 Mar 2004 18:14:04 -0000 On Mar 3, 2004, at 12:56 PM, Martin McCormick wrote: > Does the ping utility do some sort of name checking when one > wants to ping a particular host by name? Ping uses gethostbyname2() to resolve the target hostname. > A person with an account on a FreeBSD system demonstrated to > me that one could successfully look up a given host using nslookup but > if you pinged that host by name as in > > ping host_name.domain, one got an immediate complaint from the ping > utility like: > > ping: cannot resolve cl_mail1.mydomain: Unknown server error That sounds about right. nslookup is a testing utility which allows one to query RRs for string you want, including ones which correspond to invalid hostnames. The underscore is not allowed in Internet hostnames-- see RFC-952 and -1123. -- -Chuck