Newbie Help: IP firewall configuration

[crzdgns1 at starpower.net]

Hello,

I am a UNIX/FreeBSD-5.3-RELEASE newbie.  I have posted several 
times to freebsd-newbies, but I think this question will get better 
reception here.  I have installed Free-BSD-5.3-RELEASE full base 
installation with X.  I am currently trying to configure my firewall.  I 
have followed the instructions in the Handbook explicitly, though I 
didn't add any scripts to my ipf.rules file.  My ipf.rules file is verbatim 
from the Handbook, though I altered some of the commented out 
sections; the rules themselves are verbatim.  I am having a difficult 
time with this specific section:

> # Allow out access to my ISP's DHCP server for cable or DSL
> networks.
> # This rule is not needed for 'user ppp' type connection to the
> # public Internet, so you can delete this whole group.
> # Use the following rule and check log for IP address.
> # Then put IP address in commented out rule & delete first rule
> pass out log quick on dc0 proto udp from any to any port = 67 keep 
> state
> #pass out quick on dc0 proto udp from any to z.z.z.z port = 67 keep 
> state

Please help.  How do I find the IP address referenced in the fourth #?  
Where is the log file that is referenced in the fourth #?  If I need to use 
find, whereis, locate, or some other command line search tool to find 
the log file, please write out the details for me, because I am really 
struggling with command line syntax at this point.  I have clearly 
suffered from too much exposure to the point and click world.

Thank you!

Mark

P.S.  Please let me know if I haven't provided enough information.