Do you have routing setup? At each of the remote offices you need to put routes on the router to the different networks. And vice versa…you need to setup the remote office networks on the router at your main location.
If you have more specific routing questions…let me know.
Here is an example:
Main Office: 192.168.0.x/255.255.255.0
-Router Internal Address – 192.168.0.1
route 192.168.1.0 255.255.255.0 192.168.0.100 (New York)
route 192.168.2.0 255.255.255.0 192.168.0.101 (Miami)
New York Office: 192.168.1.x/255.255.255.0
-Router Internal Address – 192.168.1.1
-Router VPN Interface – 192.168.0.100
Miami Office: 192.168.2.x/255.255.255.0
-Router Internal Address – 192.168.2.1
-Router VPN Interface – 192.168.0.101
If VPN Device is also the router then the default route should be all that is needed. If you have separate devices then you need to set the routes to use the VPN device as the next hop address.