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#! rnews 5135 bsd Path: euryale.cc.adfa.oz.au!platinum.sge.net!como.dpie.gov.au!news.gan.net.au!act.news.telstra.net!vic.news.telstra.net!news.mira.net.au!news.netspace.net.au!news.mel.connect.com.au!munnari.OZ.AU!news.ecn.uoknor.edu!feed1.news.erols.com!howland.erols.net!ais.net!vixen.cso.uiuc.edu!saluki-news.it.siu.edu!slip106.termserv.siu.edu From: jimd@slip106.termserv.siu.edu (Jim Dutton) Newsgroups: comp.unix.bsd.freebsd.misc Subject: Re: Hostname for box w/ part time internet connection Date: Mon, 30 Jun 1997 00:58:04 CST Organization: Southern Illinois University Lines: 97 Sender: NNTP@slip106.termserv.siu.edu Message-ID: <24aac599.u9t27e.1@slip106.termserv.siu.edu> Reply-To: jimd@slip106.termserv.siu.edu NNTP-Posting-Host: slip106.termserv.siu.edu Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: quoted-printable Comment: AmigaNOS v2.9p In-Reply-To: <mt37p5.vq1.ln@shift.lan.awfulhak.org> (from brian@shift.lan.awfulhak.org (Brian Somers)) (at Mon, 30 Jun 1997 02:59:18 +0100) Xref: euryale.cc.adfa.oz.au comp.unix.bsd.freebsd.misc:43730 Hi Brian, on Jun 30 you wrote: [...] > If the truth's to be known, IMO, a machine name is bogus to start Not true. > with. If I have a machine with N network interfaces, then by > definition, I have N names. So what makes any one of these names Not true. Haven't you ever heard of MULTIHOMED hosts? In the DNS, there may be multiple A records with the same hostname. This constitutes ONE host with N addresses, one for each interface. A variant on this is ALIAS IP addresses defined via IFCONFIG for the same interface, but there still is the question of proper DNS definitions. [...] Brian - I think that you and I are talking about two different things; two different kinds of networks/network setups. Isolated LAN's (most likely without DNS) don't have as much of a need to worry about proper hostnames since nobody else in the world will see them. A properly configured Net-10 network is required by RFC to keep ALL of its interna= l names (and addresses) from ever leaving said network. When you give the blanket "choose any name" response to someone who is connecting to the Internet, you are implying that there are no RFC's (or "regulations") that govern host definitions on the Internet, but th= is is not the case. > So what ? Any problems resulting are IMO software bugs. Umm - how is choosing a hostname a software bug, when it was a HUMAN that configured the name into the software??? > Of course in the above example, 10.0.1.4 shouldn't really > be allowed to do things like send mail and post to usenet - > there's no way for that machine to create correct From: > lines or to create unique message ids. This is circumvented > (in my case) by hacking sendmail full of things like > MASQUERADE_AS, and setting "reply-to" addresses in usenet. Ah, so you DO use proper (DNS) hostnames, somewhere - thank you. > A good example is this message. It's posted from that 10.0.1.4 > machine (ok, in practice, 10.0.1.1 *is* a gateway!). I've called > my LAN "lan.awfulhak.org" because I own "awfulhak.org" and know Hmmm - here is another difference between what you and I are talking about. You have your OWN network with its OWN registered Internic domain. Most people your advice is going to, do NOT have this type of scenario (as was particular to our local student). Since you already OWN "awfulhak.org", you (and you alone) have the righ= t to choose anything to the left of that domain name (considering RFC constraints of course). But then, what you choose will be meaningless t= o the rest of the Internet if it isn't defined in a DNS. Users who do not OWN their own network (properly Internic registered) do NOT have the legal right to choose whatever they want for their host= name when they connect that host to the Internet (or perhaps some other loca= l organizational network). This is where the suggestion of "just choose anything" leads people into trouble (ie; reverse name lookup security, refused E-mails, responsible DNS Admins, etc.). > > Anthony - take a look at the MANual page for PPPD. It should have s= ome > > information on setting up an "IP-UP" script for use with PPP which = you > > SHOULD USE to properly set your hostname and IP address to what is > > determined during the PPP negotiation. I can post a sample script l= ater > > (with IFCONFIG, and HOSTNAME commands) if need be. >=20 > I hope this doesn't involve changing your "hostname" while running. > This gets tricky. You've got to at least HUP sendmail (assuming it's > being run with a full path name), and you must restart things like > rwhod & (old versions of) nmbd and any other brainos that use hostnam= e. The IP-UP script invoked by PPP can take care of all of this, so there = is no need to worry anything getting tricky. Use the script to IFCONFIG th= e dial-up/PPP interface (any other interfaces would simply use the static /etc/hostname.... configuration process), set the HOSTNAME according t= o what PPP returned, and recycle or start any other tasks that are depend= ent upon the current hostname, if need be. Tres simple.