This post will show you how and why to disable IPv6 on Mac. You can turn off IPv6 by going to System Preferences > Network > Advanced > TCP/IP tab > Configure IPv6. Set this to disabled.
If this fails, then flush the DNS using the Terminal (utilities folder under Applications) with these commands:
OS 10.4 (Tiger) and earlier:
OS 10.5 (Leopard) and later:
OS 10.7(Lion) Open up the terminal and type in these console commands:
networksetup -setv6off Ethernet
networksetup -setv6off Wi-Fi
networksetup -setv6off "USB Ethernet"
If these commands don't get the proper device or if you're using an external adapter, look for the device name with:
networksetup -listallnetworkservices | grep -v asterisk
Then type the same commands with your device name for X
networksetup -setv6off X
Why Disable IPv6?
For one thing, some Apple computers may experience issues connecting reliably to an enterprise network. In a lot of cases where strange wireless issues could not be timely troubleshooted, turning off the IPv6 protocol reduced the occurrence of the wireless issues.
Another reason to disable IPv6 is if you meter the availability of wireless on your enterprise network. A lot of colleges seem to do this. Disabling IPv6 will prevent students in the know to tunnel to other students to steal their remaining bandwidth.
That's how to disable IPv6 on Mac. Did you run into any issues with this? Do any of you have IPv6 enabled networks?