Re: [Asrg] 0. General - Administrative - for M. Wild
Brad Knowles <brad.knowles@skynet.be> Sat, 20 September 2003 01:37 UTC
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To: "Peter J. Holzer" <hjp-asrg@hjp.at>
From: Brad Knowles <brad.knowles@skynet.be>
Subject: Re: [Asrg] 0. General - Administrative - for M. Wild
Cc: asrg@ietf.org
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Date: Thu, 28 Aug 2003 23:59:29 +0200
At 5:04 PM +0200 2003/08/28, Peter J. Holzer wrote: > Still, I don't think there are many legitimate sites which don't have an > A record. Requiring the sender to send a FQDN which resolves to the > sender's IP address doesn't seem unreasonable to me (even for dynamic > IP-Addresses, you can use dyndns.net or a similar service). Check the recent traffic on NANOG. Because of stupidity on the part of AOL, they've been discussing this subject intensively. I've been tagging 75-90% of the recent messages as input for the BCP review. In short, let me say that I used to think this was a good idea, but my views are in the process of changing. Maybe we could tag and score on the basis of whether or not the sender's IP address has proper reverse DNS (or whether the sender's domain name exists in the DNS and/or in some sense "matches" the IP address of the incoming connection), but I think it would be foolish in the extreme to outright reject messages on this basis. > In fact, > looking at my log files this seems to be a very good indicator of > legitimate mail servers (I checked several weeks of logs some time ago > and only found one legimitate server which identified itself with an > unresolvable name (I think the box is NATted). I'm NAT'ed. Many people on NANOG appear to be in similar situations, or have run into them frequently. Just because we haven't personally experienced a particular situation doesn't mean that this would necessarily make itself a good target for filtering and outright rejection. -- Brad Knowles, <brad.knowles@skynet.be> "They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety." -Benjamin Franklin, Historical Review of Pennsylvania. GCS/IT d+(-) s:+(++)>: a C++(+++)$ UMBSHI++++$ P+>++ L+ !E-(---) W+++(--) N+ !w--- O- M++ V PS++(+++) PE- Y+(++) PGP>+++ t+(+++) 5++(+++) X++(+++) R+(+++) tv+(+++) b+(++++) DI+(++++) D+(++) G+(++++) e++>++++ h--- r---(+++)* z(+++) _______________________________________________ Asrg mailing list Asrg@ietf.org https://www1.ietf.org/mailman/listinfo/asrg
- [Asrg] 0. General - Administrative - for M. Wild Yakov Shafranovich
- Re: [Asrg] 0. General - Administrative - for M. W… Brad Knowles
- Re: [Asrg] 0. General - Administrative - for M. W… David Wilson
- Re: [Asrg] 0. General - Administrative - for M. W… Brad Knowles
- Re: [Asrg] 0. General - Administrative - for M. W… Richard Rognlie
- Re: [Asrg] 0. General - Administrative - for M. W… Peter J. Holzer
- Re: [Asrg] 0. General - Administrative - for M. W… Hector Santos
- 7. BCP - Mail Administrators (was Re: [Asrg] 0. G… Yakov Shafranovich
- Re: [Asrg] 0. General - Administrative - for M. W… Richard Rognlie
- Re: [Asrg] 0. General - Administrative - for M. W… Scott Nelson
- RE: [Asrg] 0. General - Administrative - for M. W… Bob Atkinson
- 7. BCP - Mail Administrators: Checking HELO (was:… Peter J. Holzer
- Re: [Asrg] 0. General - Administrative - for M. W… Steven F Siirila
- Re: [Asrg] 0. General - Administrative - for M. W… Hector Santos
- RE: [Asrg] 0. General - Administrative - for M. W… Bob Atkinson
- Re: 7. Best Current Practices (was Re: [Asrg] 0. … Brad Knowles
- Re: [Asrg] 0. General - Administrative - for M. W… Brad Knowles
- 7. BCP - Mail Administrators - rDNS (was RE: [Asr… Yakov Shafranovich
- Re: [Asrg] 0. General - Administrative - for M. W… Steven F Siirila
- Re: [Asrg] 0. General - Administrative - for M. W… Richard Rognlie
- Re: [Asrg] 0. General - Administrative - for M. W… Richard Rognlie
- Re: [Asrg] 0. General - Administrative - for M. W… Scott Nelson
- Re: [Asrg] 0. General - Administrative - for M. W… Richard Rognlie
- [Asrg] Re: 7. BCP - Mail Administrators - rDNS (w… Brad Knowles
- Re: [Asrg] 0. General - Administrative - for M. W… Brad Knowles
- Re: [Asrg] 0. General - Administrative - for M. W… Brad Knowles
- Re: 7. BCP - Mail Administrators: Checking HELO (… Brad Knowles
- Re: 7. BCP - Mail Administrators: Checking HELO (… Peter J. Holzer
- Re: [Asrg] 0. General - Administrative - for M. W… Brad Knowles
- Re: [Asrg] 0. General - Administrative - for M. W… Richard Rognlie
- Re: 7. BCP - Mail Administrators: Checking HELO (… Brad Knowles
- Re: [Asrg] 0. General - Administrative - for M. W… Brad Knowles
- Re: [Asrg] 0. General - Administrative - for M. W… Steven F Siirila
- Re: 7. BCP - Mail Administrators: Checking HELO (… Yakov Shafranovich
- Re: 7. BCP - Mail Administrators: Checking HELO (… Brad Knowles
- Re: [Asrg] 0. General - Administrative - for M. W… Brad Knowles
- 6. Proposals - DNS-based - RMX (was Re: [Asrg] 0.… Yakov Shafranovich
- Re: 7. BCP - Mail Administrators: Checking HELO (… waltdnes
- Re: 6. Proposals - DNS-based - RMX (was Re: [Asrg… Steven F Siirila
- Re: 7. BCP - Mail Administrators: Checking HELO (… Steven F Siirila
- RE: 7. BCP - Mail Administrators: Checking HELO (… Tom Thomson
- Re: 7. BCP - Mail Administrators: Checking HELO (… Hector Santos
- [Asrg] Re: 6. Proposals - DNS-based - RMX Hector Santos
- Re: 7. BCP - Mail Administrators: Checking HELO (… Peter J. Holzer
- Re: [Asrg] 7a: To consent, or not to consent Alan DeKok
- Re: [Asrg] 7a: To consent, or not to consent Liudvikas Bukys
- Re: 7. BCP - Mail Administrators: Checking HELO (… Brad Knowles
- Re: 7. BCP - Mail Administrators: Checking HELO (… waltdnes
- Re: [Asrg] 7a: To consent, or not to consent Troy Rollo
- Re: 7. BCP - Mail Administrators: Checking HELO (… Steven F Siirila
- [Asrg] Re: 7. BCP - Mail Administrators: Checking… Chris Lewis
- Re: 7. BCP - Mail Administrators: Checking HELO (… Jose Marcio Martins da Cruz
- Re: [Asrg] Re: 7. BCP - Mail Administrators: Chec… Steven F Siirila
- Re: 7. BCP - Mail Administrators: Checking HELO (… Steven F Siirila
- RE: [Asrg] 7a: To consent, or not to consent Eric Dean
- Re: [Asrg] 0. General - Administrative - for M. W… Brad Knowles