I need some advice from you guys: I'm dealing with a custom loadbalancer/software for which we will use 2 main servers and about 8 slave servers. In short: User sends request to main server, main server will receive and handle the requests, sends a request to a slave server and slave server should send data DIRECTLY to the "user". User - Main server Main server - Slave server Slave server - User The reason for which data should be send directly to the user and not through the main server is because of bandwidth and low budget. Now I have the following idea's: -IPinIP, but that is not possible in Layer7 (so far i know there some expensive routers for that) -IP Spoof, using C/C++ we will make it look like the reply came from main server. But I was thinking, perhaps the reply "slave server - User" could just come from a different IP without causing issues in the firewall from the user or his anti-virus. I don't know so well about "home" firewalls/routers and/or anti-virus software. I guess the user machine wouldn't handle it well?