A few month ago I found a small bug in PANOS, the operating system from Palo Alto Networks. It is related to an IPv6 enabled management interface. The MGT address was not reachable when the firewall operates in layer 2 mode, that is, had layer 2 interfaces along with VLANs. Luckily, this bug is fixed with the new software version 6.1.2 which was released this week (bug ID 67719).
Following are a few listings that show the incomplete handling of the IPv6 neighbor cache of the MGT interface in the old version (pre 6.1.2).