Microsoft ISA Server or Internet Security and Acceleration Server easily manages connections between the networks. Following are the features and pre-requisites of ISA Server :
Administrative access to the ISA Server that you are using is really important as you will be able to clarify the physical network connected to ISA Server. You will be able to do this due to the multi network model used by ISA Server. Prior to this, make sure that you create networks in ISA Server 2006 as this is the basic element of the server.
2) Network rules
All the networks should be related to the networks by the ISA Administrator between networks where network traffic should flow through. This can be done only after the networks are defined. A couple of network rules can be defined with ISA Server 2006. They are listed below :
A bi-directional network connection is established between two networks if a network rule is established through Route and due to this the original IP address is routed between the networks involved.
b. NAT: A unidirectional network connection is established if the network rule is established through type NAT (Network Address Translation) and the IP addresses are replaced with the IP address of the corresponding ISA Server network adapter from the network segment.
3) Firewall rules : The network traffic should be controlled with Firewall rules between all the networks which are involved once the network