In message <4aa58174.6010...@mail-abuse.org>, Douglas Otis writes: > On 9/5/09 5:53 AM, Andrew Sullivan wrote: > > I claim that we need to provide support for the network that people > > are actually building. That often includes things that we would not > > do ourselves, and that we think would be better done otherwise. > > There are valid reasons to formally make statements about a practice, > whether that rules the day is a different matter. There is a practice > promoted, in respect to IPv4, where the dynamic nature of an IP address > is to be divined by labels used in the reverse DNS PTR records. While a > large number of legitimate MTAs publish PTR records, there is also a > number that do not. This varies from region to region.
Which was always a error prone practive. > As a practical matter, does it make sense to continue this practice for > IPv6? Our experience found that checking for these records has required > much greater resources due to high levels of abuse and large numbers of > reverse DNS timeouts delaying connection disposition. While legitimate > MTA often have PTR records, not all do. Illegitimate MTA lacking an > operational server in the reverse address space end up comprising the > majority of traffic seen. In theory there is nameserver for every address. You should be complaining to the RIR's / LIR's if the ISP's are not running nameservers after requesting delegation. All delegations are requested. Illegitimate MTA'a may not have a PTR but a server should still be responding with a negative response. Also I don't see what this has to do with populating the reverse tree or not. It may have to do with delegating only to CPE equipment but that is a orthoganal issue. > Keeping histories (persistent caches) about which MTAs offer which label > type in their reverse entry can be handled in the IPv4 address space. > As a practical matter, this is not easily done for IPv6. Does it make > sense from an operational standpoint for ISPs to differentiate between > residential services by using "different" labels in the reverse zone? > > -Doug Mark -- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: ma...@isc.org _______________________________________________ DNSOP mailing list DNSOP@ietf.org https://www.ietf.org/mailman/listinfo/dnsop
