My computer does not appear on Apple TV for music sharing. itunes v 126.96.36.199 & Home Sharing is on. McAfee Security Centre controls my firewall settings. I do not have TCP Port 3689 or UDP Port 5353 in my list of available ports.
if you pull the power to your modem and just have a LAN setup not connected to the internet then
it's perfectly save to disable the firewall 100% and if it works then you know for sure that mcafee is the cause
and then getting info about how one get it to open ports will likely have higher success rate at macafee's forum
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