Resolving Server IP Address of Service for Multiple Networks

A network service composed of multiple servers sometime needs to be deployed in a multiple-networks environment, where all networks are isolated and unable to connect to each other, but the service must serve all networks at the same time. Services in this kind of environment (including NAT environment) should solve a problem that how to find the correct IP addresses of the servers for clients in different networks. Every network deploying a DNS server is a common solution, but it does not work in some cases. We can group the servers' IPs according to the networks they belong to firstly, and then find out the correct server IPs that client needs in different networks depending on the client address or the address of one server that client knows. According to service protocols used, different situations should choose different methods.