Update: Good news! I am now able to get onto the 5GHz SSIDs. What changed? I rebooted my router, and it now seems OK.

So I may have cried Wolf about this problem, and incorrectly blamed Mavericks. The problem seems to have gone away after the router reboot. Whew! I still don’t know why I got the message that the previous connection was “open” not wpa2-personal. But I’ll take it.

Original posting follows:

I upgraded my 2.3GHz MacBook Pro to Mavericks yesterday, and had trouble with Wifi on 5Ghz. I’m using a Netgear WNDR3800 using the CeroWrt firmware. It had previously worked great on both the 2.4 and 5 GHz channels for this computer, and the others in my house.

After the installation, I selected one of the 5GHz SSIDs, and got the message, “‘CEROwrt-guest5’ was previously joined as Open, not WPA2 Personal.”

That’s not correct – up until the upgrade, that SSID had definitely been WPA2-Personal. So after casting about (turning Wifi on/off, etc). I finally went to the System Preferences and removed the SSID by clicking the “-” button from the Wifi-Advanced settings.

But this doesn’t seem to have solved the problem: Now I see a message, “The Wi-Fi network ‘Cerowrt-guest5’ could not be joined.” when I select that SSID from the Wi-Fi menu.

So I’m stuck. 2.4GHz works fine (both on an open SSID, and one with WPA2-Personal), but I have not been able to make 5GHz work. No workarounds yet, and a quick scan of Apple’s forums don’t have any indication of a fix.

See Update above – things are working fine after rebooting my router.

I purchased this VPS from HostFolks for testing IPv6. The VPS came with a handful of IPv6 addresses in addition to the single IPv4 address they normally provide. (Be sure you ask for a server in Germany, or verify that the VPS does have IPv6 capability – not all their sites do.)

IPv6 really “just works out of the box”, unless you need to do something tricky on your system. The web server, ssh connection, etc. all acted as expected. I did have to add special configuration (udp6) for the SNMP agent, but that’s a pretty specialized configuration.

Update – August 2019: Alas, hostfolks.com seems not to be in business, but virtually all VPS providers can now handle IPv6. (In fact, run away if they don’t offer IPv6.) I’m hosting this site on Ramnode.com now, and use it for all my VPS systems…