'Portable' branch office VPN solution sought

[GerryGerry]

My school has a modest I.T setup with several (30 approx) PCs connecting to a 2008r2 server, most are desktops but 8 are laptops connecting via WiFi. They all log into the severs AD domain.

The server handles DHCP and DNS (LAN 10.0.10.xxx) as is standard. We do have a fixed WAN IP address.

 

The school wants to implement an admin type office in a public shared office space (located about 1½mile away), what would I need (if even possible) to set up a router in the shared office which would allow computers / laptops to connect and login to the server in the main site? Effectively Id like the router to handle some type of VPN tunnel in such a way as the computers connecting to it will be given their IP address from the DHCP server in the main site so that they would be on the same subnet.

 

The router on the shared office will get its IP via DHCP but I have no control over anything the WAN side of the router (I do believe that the public shared office does not have a fixed WAN IP although they've told me very rarely changes)

 

The school have a watchguard T10 device and are on (like everyone else I think) a very tight budget

Any pointers would be much appreciated.

Edited February 8, 2018 by GerryGerry

[karldenton]

We have a Sophos UTM and at our smaller sites have a Sophos RED50. It essentially is like running a cable between the sites. Users get an IP address from the red but they access the domain like they are logging on at the main site. It’s seamless.