Xref: utzoo comp.mail.uucp:4040 news.sysadmin:2837 Path: utzoo!attcan!uunet!tut.cis.ohio-state.edu!zaphod.mps.ohio-state.edu!rpi!sci.ccny.cuny.edu!phri!roy From: roy@phri.nyu.edu (Roy Smith) Newsgroups: comp.mail.uucp,news.sysadmin Subject: Re: Regarding earlier post on domains. Message-ID: <1990Mar6.154336.11049@phri.nyu.edu> Date: 6 Mar 90 15:43:36 GMT References: <75@dynasys.UUCP> Sender: news@phri.nyu.edu (News System) Organization: Public Health Research Institute, New York City Lines: 34 In article <75@dynasys.UUCP> jessea@dynasys.UUCP (Jesse W. Asher) writes: > Question: Why in the world would I want to have mail sent to another > site just so that site could send it to me? If, for example, my domain > is "dynasys.com", what is the advantage of having my mail sent to the > entity that takes care of the "com" domain only to then be sent to me? One common confusion (and I admit, I was confused by this myself) is that domain names, IP addresses, and mail paths are all, at least in the general sense, orthagonal concepts. There is no reason why, just because you are a top-level .com domain that the .com nameserver has to have anything to do with your mail other than handing out your nameserver resource records (RRs) to anybody who asks for them. Imagine the following. I've got a bunch of machines with names of xx.phri.nyu.edu. They all happen to be on the same ethernet, with IP addresses of 128.122.136.xx, but that doesn't mean anything. In fact, there is a machine on my ethernet with a 128.122.136.xx which isn't in the phri.nyu.edu domain. Now, let's say I set up a machine at home. It's owned by phri, and used for phri business, so we decide it should have a phri name. We call it foo.phri.nyu.edu. It's not on the Internet, but does have a uucp link to phrivax.phri.nyu.edu. We just have to install an MX record saying that phrivax.phri.nyu.edu is where you should send mail for foo.phri.nyu.edu. Now, lets say that the phone call involved in that would be long distance and I'd rather not pay those bills, and there just happens to be a site on the Internet, say bozo.com, down the street from me that is willing to set up a uucp link to me and be my mail exchanger. Fine, we take out the MX record described earlier and put in one saying that bozo.com is now the mail exchanger for foo.phri.nyu.edu. -- Roy Smith, Public Health Research Institute 455 First Avenue, New York, NY 10016 roy@alanine.phri.nyu.edu -OR- {att,philabs,cmcl2,rutgers,hombre}!phri!roy "My karma ran over my dogma"