Yes, I agree with you. There has to be a bug on iTunes.
I wonder if you have tried my solution: https://discussions.apple.com/message/17202885#17202885
I wonder if my solution would work for anybody.
Another thing I found out about this problem is the "time setting" between your PC and Apple TV. They have to be the same time zone, or exactly same time. In my Apple TV 2, I switched off Automatically setting the time, and I assigned the time zone zone manually. My Home Sharing has been working past 6 days with my solution (refer to the above link). Then last night, I was just playing with the Apple TV 2 setting, and accidentally switched on time to Automatic. Guess what? My Home Sharing immediately dropped! I have to switched off Home Sharing from my PC's iTunes, re-shared it. (I also had to quit iTunes and reopened for Apple TV to discover the Home Sharing.)
My understanding is if you set time zone to manual on your Apple TV, Apple TV would grab the time from your PC's clock instead of a time (NTP) server from Apple.
So, guys, while you have been beating the network settings on your routers, try to see if the time zone on both your PC and Apple TV settings are the same. Try to see if manually setting time zone would work. And try Auto too. Remember, sometimes you need to re-share your Home Sharing from PC. Sometimes, you have to re-launch iTunes after you initiate Home Sharing for Apple TV to 'discover' the Home Sharing. (But once Apple TV locks into Home Sharing from your PC, the media library on Apple TV should always be there!)
I have just used some free software called nmap and got it to do a full TCP/UDP scan on my apple TV and it shows the following ports open (This is without any router port forwarding or triggering in place):
Discovered open port 3689/tcp on 192.168.7.33
Discovered open port 62078/tcp on 192.168.7.33
Discovered open port 7000/tcp on 192.168.7.33
Discovered open port 7100/tcp on 192.168.7.33
Discovered open port 49152/tcp on 192.168.7.33
Discovered open port 5353/udp
Despite the above ports being open/available and the fact I have a 'tested' WIRED network the apple TV still drops home-sharing every now and then - so I am starting to suspect it is either iTunes software (v10.5.2.11) or the latest firmware within apple TV.
Using nmap is a good start. But I would like to clarify the proper way to use this tool. Instead of scanning your Apple TV for open ports, you should use a 3rd device (PC or Mac) to scan your original PC/Mac (with iTunes) to see if those Home Sharing essential ports (3689/5353/123/etc) are opened for Apple TV to communicate your PC's iTunes properly. Using nmap tool to scan Apple TV is rather misleading for yourself, because you assumed the ports on Apple TV are now open, therefore Home Sharing should work. As the matter of fact, these ports on your Apple TV are "always" open. They are never closed. The application/program/utilities/libraries on Apple TV always keep these ports open so that Home Sharing would work flawlessly.
What's in question is whether these ports are open on your PC or Mac. I think there are a lot of free 3rd party tool to check open ports on your PC. Or I think you can use "netstat -an" if you have Windows. If not open, then you need to work on the Firewall rules to open the ports on your PC.
Hope this helps!
I have several PC's on my home network and Home Sharing between them has been fine but the Home Sharing on Apple TV (now and then) wont show any of my PC's... I switch it off at the power and back on again and the PC's return in the computer list... after a while of using Apple TV, I put it in 'suspend' then switch off the Sony TV and sometime later when I return and wake up apple TV by pressing the menu button the PC's in Home sharing 'sometimes' disappear ... but not always. Anyhow switching off the ATV and powering it back up again and the PC's re-appear.
I have just done netstat -an on my main PC here are the results with ATV turned on (IP address 192.168.7.33) and streaming - note this is a short 'extract' from my netstat results NOT the full output:
WITH ATV CONNECTED & STREAMING FILM
TCP 192.168.7.13:3689 192.168.7.33:51243 ESTABLISHED
TCP 192.168.7.13:3689 192.168.7.33:51244 CLOSE_WAIT
TCP 192.168.7.13:3689 192.168.7.33:51245 ESTABLISHED
TCP 192.168.7.13:3689 192.168.7.33:51261 ESTABLISHED
UDP 192.168.7.13:1900 *:*
UDP 192.168.7.13:5353 *:*
UDP 192.168.7.13:49234 *:*
Not sure if this takes me any further but when I get a little more time I will run nmap from one of my other computers and point it at my main PC.
Whilst doing this I was wondering if windows PC power management/screensaver etc may have something to do with the dropped connection after the ATV has become 'idle' or suspended... anyhow that is something else I will try aswell in the coming days.
rogsf - thanks for taking the time to reply to my earlier posting - it is appreciated :-)
I had the similar problem too before I fixed it. My Apple TV would loose my PC all of the sudden, even I am not playing any songs from my iTunes library. I don't think it's your PC's pwr mgmt or screensaver. The way I fixed my problem was actually 2 steps:
1. Make sure the time zone matches that on your PC. Try set your time zone to manual in ATV.
2. Uninstall the latest versino of iTunes, and install version 10.3.1 (released in July 2011)
Makes me laugh seeing as how all of us are doing everything we can with no feedback or help from Apple. Clearly this is not a network problem. This is a huge BUG between iTunes, ATV2 and Home Sharing Software. It's a bug that Apple cannot fix or doesn't care about. There is no rational reason to have people playing around their ports, routers, firewalls, base stations... If this is the case then Apple is not doing their job with creating products that "just works" and doesn't require "IT" support. In this case, Apple is failing!
I have the same problem with home sharing and airplay working with my music on iTunes for mac for about 20 minutes on my apple tv 2. Every once in awhile, airplay works, and I can see the airplay icon in iTunes occasionally. And I am able to stream my iTunes library to apple tv occasionally, but both drop out at about 20 minutes. Home sharing is on both in iTunes and ATV2, pw for iTunes and ATV2 match. My internet is through password secured wifi in my building, so I don't have access to an ethernet port or a router. I don't know why it would work for a little bit, then stop, but if anybody has any ideas, let me know. Thanks!
Wish I had a dollar for every time someone on this forum said "it's clearly not a network issue". Of course many of the fixes involve network settings.
I don't know who told you that Apple products "just work" but they lied to you. I've been using Apple products for about 20 years now and while I believe they are more reliable, they certainly don't all just work out of the box. Otherwise this forum would have tumbleweeds rolling through it.
The rational reason that people have to adjust their network settings is that the network is how the devices communicate... if they can't communicate, then they won't work.
I joined this thread 'round about page 23, and I have seen the results of all the fixes that Apple has made; it used to be all kinds of different problems, with different configurations, but now it seems to be just Windows 7 and closed ports. So obviously Apple has made progress with this issue, but is not done yet.
In the interest of helping to get these last bugs worked out, I strongly suggest going over to http://www.apple.com/feedback/appletv.html and ranting there. Be sure to give as much detail as you can about your system, what you've tried, and the results so the engineers can have a better idea of what is causing the problems. Or call them, or go to an Apple store.
Or sell the thing and buy something else. Personally I'll keep mine, but I'm not recommending that my parents get one yet.