nanog mailing list archives
Re: comcast ipv6 PTR
From: Lee Howard <Lee () asgard org>
Date: Tue, 15 Oct 2013 02:28:16 +0300
On 10/10/13 1:09 AM, "Barry Shein" <bzs () world std com> wrote:
On October 9, 2013 at 20:18 cma () cmadams net (Chris Adams) wrote:Once upon a time, Barry Shein <bzs () world std com> said:It's very useful for blocking spammers and other miscreants -- no reason at all to accept SMTP connections from troublesome *.rev.domain.net at all, no matter what the preceding NNN-NNN-NNN-NNN is.If you are going to block like that, just block anybody without valid reverse DNS. If you don't trust provider foo.net to police theirusers,why trust them to put valid and consistent xx-xx-xx-xx.dyn.foo.net reverse?Because they do, they just do. This isn't a math proof, it's mostly social engineering. The providers aren't trying to fool anyone, in general, it's just that clients and websites get botted.
Except the point of this thread is that they don't. Is it easier to block inbound mail from hosts with certain high-level domain names in their PTRs than to block ranges of IP(v6) addresses? Easier for whom? Lee
Current thread:
- Re: comcast ipv6 PTR, (continued)
- Re: comcast ipv6 PTR Paul Ferguson (Oct 09)
- Re: comcast ipv6 PTR Chris Adams (Oct 09)
- Re: comcast ipv6 PTR Livingood, Jason (Oct 09)
- Re: comcast ipv6 PTR Blair Trosper (Oct 09)
- Re: comcast ipv6 PTR Chris Adams (Oct 09)
- Re: comcast ipv6 PTR Joe Abley (Oct 09)
- Re: comcast ipv6 PTR John Levine (Oct 09)
- Re: comcast ipv6 PTR Barry Shein (Oct 09)
- Re: comcast ipv6 PTR Chris Adams (Oct 09)
- Re: comcast ipv6 PTR Barry Shein (Oct 09)
- Re: comcast ipv6 PTR Lee Howard (Oct 14)
- Re: comcast ipv6 PTR Barry Shein (Oct 14)
- Re: comcast ipv6 PTR Franck Martin (Oct 14)
- Re: comcast ipv6 PTR Paul Ferguson (Oct 14)
- Re: comcast ipv6 PTR Barry Shein (Oct 14)
- Re: comcast ipv6 PTR John Levine (Oct 14)
- Re: comcast ipv6 PTR Blair Trosper (Oct 14)
- Re: comcast ipv6 PTR Chris Adams (Oct 15)
- Re: comcast ipv6 PTR Brielle Bruns (Oct 15)
- Re: comcast ipv6 PTR Andrew Sullivan (Oct 15)
- Re: comcast ipv6 PTR Barry Shein (Oct 14)