Date: Mon, 28 Sep 1998 14:31:58 -0400 From: Dennis Rockwell <dennis@bbn.com> To: stable@FreeBSD.ORG Subject: Re: resolving ips? Message-ID: <199809281830.OAA07193@po1.bbn.com> In-Reply-To: Message from "Chad R. Larson" <chad@freebie.dcfinc.com> <199809251810.LAA04947@freebie.dcfinc.com> .
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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
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