mark@cbnews.ATT.COM (Mark Horton) (09/02/88)
>>I would maintain that there is a lot of interest in parks. They are >>what was intended by the MX system in the first place. No one wanted >>every measley PC running UUPC to get an MX record! That is an abuse >>of the nameservers, and a disservice to the community. > >Er, how's that? The only site that could possibly be inconvenienced by >a lot of MX records is the site where the nameserver database is stored. >Each site in a domain may have a unique entry, or maybe there's a >wildcard record. In either case, a query will use exactly the same amount >of network bandwidth. While the size of the nameserver database is a concern, a far more important concern is the load on the forwarders. A typical forwarder implements forwarding for each domain by adding a line to sendmail.cf. If there are more than a few dozen such lines, the sendmail.cf file gets large, and more of a problem, mail gets slow, since sendmail.cf is processed sequentially for each piece of mail. Thus, forwarders are a critical resource. Several forwarders are running software that is smarter, but this require an enhanced sendmail or the equivalent. Another potentially high cost for a second level domain is inter-network coordination. If you consider the four major American academic networks: DDN, CSNET, BITNET, and UUCP, using the domain system independently, these networks are sharing the 2nd level name space under COM, EDU, GOV, MIL, ORG, and NET. In theory, each of them should have a full list of each others 2nd level domains, so they know which net to forward a piece of mail to. In practice, most of these get bumped upstairs to DDN as the ultimate authority, until we get something better working. By using parks, we can get several small organizations under one 2nd level domain. The costs above go with 2nd level domains, so there is an economy of scale. Mark
wisner@killer.DALLAS.TX.US (Bill Wisner) (09/02/88)
Still no good. Nameservers and MX forwarders are totally seperate. A nameserver can have a unique record for every host, while an MX forwarder simply special-cases everything in the domain and transfers it to the domain's gateway. In this scenario, the forwarder will never receive a piece of mail for an invalid host. Any Internet site can be a forwarder. The idea that only a few specially- equipped installations can do it is a myth. All it takes is a friendly postmaster.
rsalz@bbn.com (Rich Salz) (09/02/88)
>Any Internet site can be a forwarder. The idea that only a few specially- >equipped installations can do it is a myth. All it takes is a friendly >postmaster. And current, working, properly-installed software. I claim that my first sentence proves that your first two sentences are wrong. /rich "I see a .cf file and think of me" $alz -- Please send comp.sources.unix-related mail to rsalz@uunet.uu.net.
ahby@com2serv.C2S.MN.ORG (ahby) (09/02/88)
In article <5384@killer.DALLAS.TX.US> wisner@killer.Dallas.TX.US (Bill Wisner) writes: >Still no good. Nameservers and MX forwarders are totally seperate. A >nameserver can have a unique record for every host, while an MX forwarder >simply special-cases everything in the domain and transfers it to the >domain's gateway. In this scenario, the forwarder will never receive a >piece of mail for an invalid host. >Any Internet site can be a forwarder. The idea that only a few specially- >equipped installations can do it is a myth. All it takes is a friendly >postmaster. I'm not disagreeing, but feel I should point out that it takes a little more than congeniality to make an Internet site a forwarder. You need the right version of sendmail, bind, and someone who really understandards sendmail.cf to make it work correctly. Even then, the number of sites who will bash your headers, munge your From: lines, etc... is large, and many people are just not willing to change. They won't believe that you are running an RFC 976 conforming mailer, and they are not interested in your reasons for wanting them to drop everything and make their machine work they way you perceive as right. These people exist (think god), but they are rare. -- Shane P. McCarron ATT: +1 612 452-9522 Project Manager UUCP: ahby@c2s.mn.org
wisner@killer.DALLAS.TX.US (Bill Wisner) (09/03/88)
>>Any Internet site can be a forwarder. The idea that only a few specially- >>equipped installations can do it is a myth. All it takes is a friendly >>postmaster. >And current, working, properly-installed software. Well.. OK. Fine. Picky, picky, picky.
gore@eecs.nwu.edu (Jacob Gore) (09/06/88)
/ comp.mail.uucp / ahby@com2serv.C2S.MN.ORG (ahby) / Sep 2, 1988 / >... it takes a >little more than congeniality to make an Internet site a forwarder. >You need the right version of sendmail, bind, and someone who really >understandards sendmail.cf to make it work correctly. Sendmail is not the only mailer out there. For exmple, I've been administering MMDF here for years, on a site that talks to nameservers, has numerous UUCP connections (both smart and simple-minded), and acts as a forwarder for several domains. I still view sendmail.cf as an OPS-5 program that has been run through sed using a rot-13'ed edit script and then hashed into 2-character words... Jacob Gore Gore@EECS.NWU.Edu Northwestern Univ., EECS Dept. {oddjob,gargoyle,att}!nucsrl!gore