Does disabling IPv6 in System Preferences solve AEBS connectivity problems?

The short version: Go ahead and disable IPv6 and see if it helps. It's all but certain you'll never notice or care that IPv6 is missing.

IPv6 is not even available from most US ISP's - which means most people can't even get IPv6 without going to a fair amount of effort - and even if you do you don't gain much from it. For the moment, IPv6 is very much a computer geek kind of thing. Think of it as something we will probably be using in 5-10 years, but not right now.

The reason for IPv6: Currently, the internet uses IPv4, which is about 25 years old. The problem is that IPv4 is running out of addresses. Even with technologies that help stretch things out, most estimates say we'll be out of IP addresses somewhere between 2010 and 2015, and then getting things to work on the internet gets complicated if you want to add any more computers.

Enter IPv6. The big thing with IPv6 is that it has a lot more IP addresses. How many more? A pretty horrifying number - I think there are more than enough for every grain of sand in the sahara desert to have several (billion?) each. There are other improvements in IPv6, but none that mere mortals need worry about.

I've done it, and it didn't make any difference on my Macbook Pro. Still dropping the connection like crazy for no apparent reason, and refusing to reconnect. If you can call it an up side, the up side is it doesn't seem to have had a negative effect on anything either.

You have to disable IPv6 on the base station, not on your computer. To do it, open the Airport Utility and click "Manual Setup." Then click on the "Advanced" button at the top (with a little gear icon) and the "IPv6" tab underneath. Set "IPv6 Mode" to "Link-local Only," click the "Update" button at the bottom, and wait for the AEBS to restart.

Since I did that, I haven't had any problems with the AEBS dropping the connection, no matter how heavily I've been using it. Good luck!

"IPv6 is not even available from most US ISP's - which means most people can't even get IPv6 without going to a fair amount of effort - and even if you do you don't gain much from it."

This is just wrong.

The default mode for IPv6 operation with AirPort Extreme is to use a transition technology (called "6to4") that requires no effort whatsoever on the part of users. If your base station gets a public IPv4 address, i.e. what every major ISP in the world provides to residential and business customers, then it just works— you don't have to do anything— and you get a native global IPv6 prefix on your wireless network.

Some popular P2P applications are starting to use IPv6 where it's available. This will make them work better on some ISP's (and possibly worse on others, where management is actively discouraging customers from using IPv6 transition technologies— I won't name names, because I could get in trouble). If turning off the IPv6 tunnel in AirPort Utility makes your life easier with your ISP, then by all means, go ahead and do it. You probably don't need to know what you might be missing. Turning it off on your Mac in System Preferences is probably pointless.

Summary: it's just not true that it's "a computer geek kind of thing" at all. Your software might be using it right now without you even knowing it. For example, you might discover that turning off IPv6 in System Preferences makes your AirPort invisible in the AirPort Utility? Why? Because IPv4 doesn't support multihoming like IPv6 does, and now your base station can't be reached until you reconfigure your network ports.

i gave this solution a try and it seems to be working. turned IPv6 to local link only last night. Left transmission on overnight with a few torrents to see if my router would crash. 8 hours later, i wake up internet is still up an torrents have been downloaded/downloading all night without a problem. I have OSX 10.4.11 and I kept the firmware at 7.2.1 I read somewhere that the 7.2 firmware addresses a security problem having to do with IPv6. So maybe when people roll back to 7.2 it is changing their IPv6 to local which is why rolling back works. I guess by 7.2.1 apple thought they had addresses the IPv6 security problem enough to have that update change IPv6 back to tunnel instead of local only.

I'll post an update if this solution stops working.

still working a few days later. No problems at all yet after IPv6 set to local. I am adding a airdisk to the AEBS so I will see how that goes.