How can I get all IP transactions (in/out) logged?

[listcomm@ml1.net]

I just want a basic log file containing the source and
destination addresses for all traffic in and out of
via PPP, so that I can keep track of what connections to
outside IP addresses are made, and from where (externally,
or from something running on my system) they originated.

I've turned on the debug mode in PPP but it doesn't seem to
provide what I want.  For instance, it logs transactions from my
system to my ISP, but doesn't log what's happening with
any greater resolution (for instance, if I ping a system
on the Internet, there's no record of the ping attempt
in any of the system log files).  The firewall as set up by
"firestarter" logs blocked firewall penetration attempts, but
not "legitimate" transactions in and out (perhaps there's a
method, which I haven't found, to change that?)

Is there any "built-in" facility that will accomplish
this, or is it necessary/possible to construct something
using "iptables", or is there a contributed app that will
do it?

I realize that there are log files for the various
servers and utilities (FTP, etc.) that contain this information
on a piecemeal basis, but it seems to me that it would make
more sense to collect it at the connection point(s) in and out
of the system, at least on an interface-by-interface basis.

Once again, I'm surprised that a Web search and various site
searches haven't turned up a solution to this.