Question : ISA Advice - Connecting 2 sites

Dear Experts,

I am currently working at a school in the UK which is set to merge with another school in the same area. Both schools are part of the local councils WAN and get internet traffic through a 100Mb link to them.

The two schools can communicate using the WAN supplied IP addresses (see diagram) however, we would like to install an ISA or TMG box at each site to minimise traffic over the already inadequate 100Mb connection.

My question is, does it matter if both sites have the same internal private ip ranges or would it be better to have these separate?
Obviously the external cards on both ISA /TMG boxes would need to be on the same range to communicate, but does it matter about the internal ranges?

Also, is there a particular template or model within ISA that I should use that is designed for this kind of setup?

Any help gratefully received.........

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Network Setup

Answer : ISA Advice - Connecting 2 sites

It has to be far better to have them as different subnets. The main reason is routing.
The type of template is irrelevant to this aspect as is determined more by what else you run - DMZ, third or fourth nics on the ISA's etc.

Keith