On Tue, 2004-03-30 at 20:53 -0500, James H. Cloos Jr. wrote:
(I don't want to use ptr because I've seen endless spam --
mostly coming from Korean ipv4s -- where the ptr was falsely
set to match the domain the mail claimed to be from....)
But they can't effect A or AAAA records pointing back to their own IP
address from your namespace, so how would this affect you?
----
4.6 'ptr'
This mechanism tests if the <sending-host>'s name is within a
particular domain.
PTR = 'ptr' [ ':' domain-spec ]
First the <sending-host>'s name is looked up using this procedure:
perform a PTR lookup against the <sending-host>'s IP. For each
record returned, validate the host name by looking up its IP address.
If the <sending-host>'s IP is among the returned IP addresses, then
that host name is validated. In pseudocode:
sending-host_names := ptr_lookup(sending-host_IP);
for each name in (sending-host_names) {
IP_addresses := a_lookup(name);
if the sending-host_IP is one of the IP_addresses {
validated_sending-host_names += name;
} }
--
dwmw2