On Tue, 4 Mar 2003, Lou Katz wrote:
your network and operation. Using these lists is a policy question for the network, and I would not like some external, probably unaccountable single point of policy.
For most purposes, network addresses are involuntarily put on various "blacklists." So it makes since to design them as a third-party architecture. And to avoid the problems of centralized control (or censorship), spread those lists out among many different organizations. However, there is one purpose these lists are used where it may be better to "go to the source." Difusing the identification of dialup addresses, and in today's network other types of dynamic connections, causes problems with out of date, or mistaken information. Some of the DNSBL get the dialup information from service providers, but unless the provider plays favorites with DNSBL providers, its hard to keep them all up to date. But when problems happen, the DNSBL goes out of business, accidently lists the wrong addresses, etc; its out of the service provider's control. Because dialup identification is generally not "punitive," I think it makes sense to give providers a mechanism to self-identify dynamic network addresses without otherwise effecting whatever naming scheme they want to use for their network, and without depending on third-parties. Fighting a two-front religious battle isn't necessary. My proposal would be something along the lines of allowing providers to use the HINFO field on dynamic network addresses. Since its a dynamic address, HINFO probaly doesn't have real hardware/operating system information. So why not register a well-known value with IANA for dynamic hosts, e.g. HINFO "DYNAMIC DIALUP". Service providers can set, maintain, update, etc their own DNS files as quickly as they get address space and start using it. If the service provider re-purposes the address space, they can change or delete the HINFO field without the trouble of coordinating changes with multiple third-parties. Remote hosts which want to deny service to dynamic hosts, such as not allowing SMTP connections, would retrieve the HINFO field along with the other information they get doing DNS lookups. If the value is HINFO "DYNAMIC WIRELESS" they implement whatever policy they want for those connections. The service provider is only giving technical facts about the access method, no personal information, no judgement about the customer using the connection. It does no good for a service provider to lie. If they lie, the other blacklists will pick them up soon enough. If the service provider is lazy, again the other blacklists will pick them up. Generally the DNS record for dialup or dynamic networks is under the control of the service provider, not the customer. But even if the service provider let customers use dynamic update to change the DNS information, any other value for HINFO or no HINFO would be treated as unknown.