I am experiencing this bug. If you clear out all the fields with spaces and then try ti save, you get the invalid ipv6 message.
I do have a sort-of work around. If you delete the DN and recreate it, then the new DN works perfectly fine.
This is four years late, but... Did you figure out the duplicate address thing? Also, the command to set a link local address is "ipv6 address FE80... Link-Local". The "ipv6 link-local ...." command changes the printed format of link-local addresses
How are these two switches connected. For vlan 5 from the fa switch to get to the l3 switch, you'll need a trunk port connecting them that bellows vlan 5Sent from Cisco Technical Support iPad App
I'm betting that if you do a show run, you'll either find those ports are trunk (switchport mode trunk) or that they are access ports with no vlan. Think of no vlan as the same as assigning them to vlan 0. Vlan 0 doesn't really exist, its more the ...