We are trying to use DynDNS with ISA 2000 but of course we have no idea what ports it rests on. We are not married to DynDns and our DSL modem does not support Dynamic DNS.
Online there are books related to the pairing but no other such information. All we want is an easy way to get the IP address since it changes constantly.
NOTE: According to TCP/View, DynDNS opens a random number of ports numbered 47xx