I recently installed McAfee and it seems to be blocking my Apple TV from syncing with iTunes on my Windows operating system. It was giving me a port 3689 error. I contacted McAfee support and they suggested to go to the McAfee SecurityCenter click on Internet & Network > Configure > Firewall Advanced Options > System Services and add Apple TV with 3689 in both the Local TCP/IP Ports and UDP Ports.
Could you explain in detail on how the devices are setup in your network?
McAfee SecurityCenter click on Internet & Network > Configure > Firewall Advanced Options > System Services Under system services click Add and specify the following you may edit the newly created one) Program name (iTunes Sharing), Inbound TCP/IP ports (3689), Outbound TCP/IP ports (3689), Inbound UDP ports (5353), Outbound UDP ports (5353).
Please keep in mind that I'm not a tech guy, so I'm not sure exactly what you're asking, but I'll try.
My iTunes is on a Dell desktop that runs on XP and is connected directly to a wireless Motorola router. My apple tv is wireless also connecting through the router. When I try to sync the itunes and apple tv, I'm getting an error code to open a communication port 3689.
I hope this is what you need. Please ask if you need more information to diagnose the problem.
This was some time ago, so I don't exactly remember how I did it. I believe I was able to manage network from the McAfee Security Center and somehow allow the appletv. I'm sorry I don't have more info for you.