Networking Properties Interfering with iTunes

[trclac]

I posted this in the Apple/iTunes forums at apple.com and in the Apple forum here, but never got a response. Maybe someone here can help, since it also involves my networking properties.

iTunes has been extremely slow to open when I launch the program, since upgrading to Win 8 (64-bit) (I am now running the latest release of iTunes -- 11.1.4 and Win 8.1 Pro (64 bit)). I went through a number of trial/error "fixes", and I "think" I found the cause --

In Network Connections, right click on "Ethernet" (I am using a desktop hard-wired to Ethernet and a Comcast cable modem, via a D-Link DIR868L (with latest F/W)), and click Properties. You then see "Internet Protocol Version 6 (TCP/IPv6)" and "Internet Protocol Version 4 (TCP/IPv4)". If you click both boxes, iTunes is extremely slow to launch. But if you only click on one of the two (i.e., only tick the IPv4 box), then iTunes launches normally and very quickly. Problem is, Windows alerts me that to run HomeGroup, I need to have both items checked, which, again, I have determed to be the culprit for the extremely slow start of iTunes.

My modem is IPv6 compliant, as is the router, but I am not sure Comcast is (I live in West Houston).

In any event, does anyone know why ticking both these boxes causes an issue with iTunes? Is it possible to tick them both and launch iTunes normally, and, if so, how?

Thanks in advance!

 

[Fardringle]

If you have IPv6 enabled, Windows 8 will try to use it first. If your ISP doesn't forward IPv6 requests properly then Windows (and in this case, iTunes) will wait for the v6 request to time out before resending it as IPv4 (which works). This will actually make everything you do on the Internet slower, but web browsers seem to be more tolerant of small delays in traffic than other programs.

edit: This is my guess at the cause, not a specific known issue with iTunes.

 

[imagoon]

Sounds like IPv6 failed and itunes fell back to IPv4. Do an IPv6 dns lookup and ping (ping -6) that IP, if you can connect then something else is wrong. If not then apple might not have the IPv6 itunes service running.

 

[trclac]

Comcast states that IPv6 is available, but I cannot seem to get it to work correctly. Is it because I am going through the DIR-868L router? Should my desktop be directly plugged in to the cable modem? I saw something about Comcast not yet supporting home networks on IPv6, so maybe that's the issue (although the DIR-868L was able to auto-configure IPv6).

Thanks.

Edit: This is what Comcast states, so it appears the desktop must be directly connected to the cable modem, which mine is not: "In our first phase of deployment, we will enable IPv6 on selected standalone computers. This is the case when a customer has just one computer, and where that computer is plugged directly into a cable modem." They say they will roll out support for home networks, but it appears IPv6 cannot be used because my DIR-868L is between the desktop and modem.