VPN newbie needs some help

[Trader's Paradise]

I've got a pair of NetScreen 5xp boxes that I am trying to setup as a proof of concept experiment.  Right now I can only "play" with them on my local network behind my fireway (192.168.x.x).  I am following the examples given in Chapter 7 of the Concepts & Examples file on the NetScreen documentation CD.  For some reason I can not establish the VPN connection.  Is it because the untrusted networks are from the same class C address space?  I know routers won't route on the same subnet but will the VPN not connect on the same subnet?   Understand I'm not new to networking (been admining LANs for about 9 years now) this is just the first time I've had to deal with VPNs.   TIA,   John Guynn System Administrator [EMAIL PROTECTED] www.tradersparadise.com