IPFW ... Options

[Jonathan Owen]

I've taken a look at the man pages of IPFW and still can't figure out a =
way to do the following:

I'm using ipfw in conjunction with natd to run a dial-up firewall and =
gateway. What I'm trying to do is to is to find a rule that will enable =
me to block access to the outside world on certain ports whilst the =
FreeBSD box is not connected via ppp, but then allow access to them when =
the box is connected. Any suggestions?

Jon Owen