[pptp-server] Can the LAN see people connected via PPTP tunnels?

[Thom Cherryhomes]

The subject says it all:

I have people doing a remote office set-up to a central LAN. They can 
connect to the LAN, and see the other machines connected directly to the 
central LAN, but the central LAN can not see the people connected via 
the PPTP tunnel, or anyone else connected via PPTP.

Is there a way we can get around this?

-Thom