RE: RKCOJOHN --- THIS DID IT!!!
Tried the other tips that seemed to be working for others to no avail.
RKCOJOHN's tip did the trick, finally.
RKCOJOHN wrote:
Folks, you could try this - it worked a charm (so far) for me.
Go into System Preferences / Network.
Choose your ethernet and/or wifi connection.
Go to "Advanced". If you're working on wifi settings, you'll need to pick the TCP/IP tab from the next window. If you're working on Ethernet settings, it should default to the TCP/IP tab.
If IPV6 is set to "off", change it to "Automatically" or put in "Manual" settings as you prefer. Apply the changes. Close iTunes & restart the Mac. Open iTunes once you're restarted and, if you're like me, your wifi sync devices will show up very quickly in the side bar.
Sync still seems to pause for a while on last step, but it has not yet failed on iPad, iPad 2, iPhone 3GS, 4S & 5.
Steve's earlier post led me down this path and prompted me to check this. I have a vague recollection that I forced IPV6 to "off" to overcome problems with prior upgrades to OS X and/or iTunes.
Hope your frustration comes to an end as, hopefully, mine has. I'm optimistic because I've been playing around for 2 days with variations of all the suggestions on this discussion. I'll post back if, as for some others, this fix only works temporarily. Good luck!
Like you, I had turned off IPv6 a while back in response to another tip about an issue I've since forgotten. If it is, in fact, required now for WiFi Sync, you'd think it would be an easy enough thing that Apple could check for when you enable it it iTunes. Display a pop-up or something, i.e. "To enable WiFi Sync of your device, you must have IPv6 enabled in your Network Settings. Click here to be taken to System Preferences."
If you are having this issue, try this and report back. Let's see if we can isolate it.