Hi!
I have been running 6.5.1.2 on a 7205 since we bought it last December. The latest WPA2 fun made me finally take the plunge, and I upgraded to 6.5.4.2.
(I have a 7005 controller with a few AP's as well, that I've been playing around with, so I'm not new to upgrading ArubaOS)
Everything seemed to go smoothly, but I was quite surprised when I had three AP's out of 120 that didn't show up on the controller after the upgrade. Those three were all at the same location.
I'm using dns discovery, and all my locations have common dns server. I put those three AP's on another vlan, and they showed up as if nothing had happened.
I then started comparing dhcp settings for the two vlan's, totally identical. I downgraded to 6.5.1.2 again, then all AP's showed up as they should. I upgraded again, to no avail.
After using all weekend thinking about this, what could possibly be different, I realized that my problematic vlan is running native IPv6 in paralell with IPv4.
Just for the fun of it, I disabled the IPv6-adress on that vlan on my firewall (Juniper SRX), and it worked! I'm not running a DHCPv6 server, but am using router advertisement.
So please help! The controller does not have any IPv6 adress, the dns-server is purely IPv4, there surely isn't any AAAA record for aruba-master, it works with 6.5.1.2.
Hope someone understands what's happening. It's the same with 6.5.4.3, btw.