Question about ports

[Dragoncrest]

	I remember someone saying how to do this, but I've since 
forgotten.  What's the command to pull down all of the source files for 
each and every single port in /usr/ports that is needed to install any of 
the ports?  AKA all of the files that should end up being stored in 
/usr/ports/distfiles

	I've searched, but I guess I'm not using the right keywords to find 
this.  What I need to do is install ports on a box with zero network 
connection to the internet.  Any help is welcome.  Thanks.