Isa 2004 & dyndns.org

Microsoft Windows

Can someone give me the instructions on which ports have to be opened for
dyndns to work on sbs2003 with Isa ? Also how to write the access rule.
Thanks Chris
I use ISA 2004 and dyndns.org, and have no need for any special rules in ISA
to make it work. I use the DirectUpdate client on the server, set up to use
a proxy server on port 8080.