WAN Vpn troubles

[mohawk24]

Hi all im looking for some advice here...

this is whati want to do....

i have 2 offices that i want to create a vpn for...

office a and office b

wireless radio ip of office a is 172.16.40.99
wireless radio ip of office b is 172.16.19.4

router ip of office a is 172.16.43.99
router ip of office b is 172.16.19.4

local subnet of office a is 192.168.4.0/24
local subnet of office b is 192.168.0.0/24

how do i configure the vpn routers to allow this tunnel??

equipment at office a is linksys fx prosafe vpn router
equipment at office b is dlink dfl-700

i have successfully vpn'ed these two offices going out to the internet first and in thru a real world ip gateway but to reduce overhead and lag i want to only go thru local isp lan...172.16..... etc...

is this possible and how do i do it....

any help would be extremely appreciated...

[M/Q]

Are the offices connected by a network other than the Internet?

If not then what you are wanting to do is not possible. Private IP addrs will not route on the Internet.

[mohawk24]

yes both offices are in the 172.16 wan network and i can ping both ends i just need to know how to setup the gateway and ipsec setting on both ends...

with specifics to ip's and such....

[M/Q]

Sorry, I am still confused. How are you connecting the two offices together. If they both have the 172.16.XX.XX IP addr scheme that means they are already on a local network or VPN. That IP addr block does not route on the Internet.

[mohawk24]

they are seperated geographically and talk via wireless lan....7 buildings in total i would like to vpn in from 6 buildings to the main building for server resources etc...