On Wed, 9 Dec 2009, Mike Lieman wrote:
Is there an RFC detailing that specific text strings must be used for static v. dynamic addresses?
There's this expired draft http://tools.ietf.org/id/draft-msullivan-dnsop-generic-naming-schemes-00.txt But really, the rdns should just clearly indicate the use of the IPs if you're going to do generic/script generated rDNS. a84-22-96-117.cb3rob.net doesn't tell me anything except that this IP is part of a large block of generic rDNS. Something like a84-22-96-117.static.cb3rob.net at least indicates that the IPs are static, while a84-22-96-117.dynamic.cb3rob.net clearly indicates the space is dynamic. Doing this takes much of the guesswork out of it when others on the net need to decide "should we accept mail from this IP?" Keeping the indicator as close as possible to the domain helps out for things that do simple string matching. i.e. with a84-22-96-117.dynamic.cb3rob.net, it's a safe bet I don't want mail from *.dynamic.cb3rob.net. That's easier to block (with a single rule) than dynamic.a84-22-96-117.cb3rob.net. Still, if you're serious about getting mail from that IP delivered, its far better to have the PTR = the domain or system name than some generic string roughly equivalent to all the neighboring IP PTRs. ---------------------------------------------------------------------- Jon Lewis | I route Senior Network Engineer | therefore you are Atlantic Net | _________ http://www.lewis.org/~jlewis/pgp for PGP public key_________