From owner-freebsd-stable Mon Sep 28 11:31:00 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id LAA27696 for freebsd-stable-outgoing; Mon, 28 Sep 1998 11:31:00 -0700 (PDT) (envelope-from owner-freebsd-stable@FreeBSD.ORG) Received: from po1.bbn.com (PO1.BBN.COM [192.1.50.38]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id LAA27691 for ; Mon, 28 Sep 1998 11:30:57 -0700 (PDT) (envelope-from dennis@bbn.com) Received: from bbn.com (DROCKWELL.BBN.COM [128.89.31.139]) by po1.bbn.com (8.8.6/8.8.6) with ESMTP id OAA07193 for ; Mon, 28 Sep 1998 14:30:30 -0400 (EDT) Message-Id: <199809281830.OAA07193@po1.bbn.com> To: stable@FreeBSD.ORG Subject: Re: resolving ips? In-reply-to: Message from "Chad R. Larson" <199809251810.LAA04947@freebie.dcfinc.com> . X-face: &R'hN{mZu#r@8b_JU\bn"!fYpP{?5k4p/(|]?.2'6;>Dc9}~t*vY=/#-:"63ya.%)%o`Kv$ u&'Ff5k&n[}QC;j7YYsR5Hl]G"E:*9Zmw;dx[sw&9Tmx_PB/7B`RdFW;#@49hJU&kW+J"<[`9^?.dQ 3]L$zK,4'=tThX$wC!M\`e*@1y Date: Mon, 28 Sep 1998 14:31:58 -0400 From: Dennis Rockwell Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On 25 Sep, "Chad R. Larson" wrote: > > > If I type "telnet 10.1.1.1", I would not expect telnet to consult a DNS > > > server to do a reverse lookup on that IP. I would expect it to consult > > > the routing table, decide that 10.1.1.1 was either on a local subnet, > > > through a remote gateway, or through the default route, and route my TCP > > > SYN packet accordingly. > > The telnet client is doing the DNS lookup (actually, a call to > gethostbyname() ) in order to be able to display the remote host's name > when you do the "status" command. It probably uses the hostname in > other places as well... Actually, it's worse than that. Most stock UNIX clients don't inspect the argument they're given, they blindly call "gethostbyname()" as a first attempt, even with a numeric address. Only after that fails (through rejection or *ugh* timeout) do they attempt to parse it as a number. I generally don't let this stand if I have another reason to modify the client. Missed most of this discussion when catching up, hope this isn't redundant. Dennis Rockwell dennis@bbn.com GTE Internetworking Powered by BBN +1-617-873-5745 Cambridge, MA +1-617-873-6091 (Fax) To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message