Key chains are sequences of keys (shared secrets). Users can configure key chains and can use keys with features that secure communications with other devices by using key-based authentication and optionally perform periodic key rotations within the chain. For OSPFv3 the new authentication feature can be applied on an interface and a virtual link.
Configuring OSPFv3 Authentication feature:
device# configure terminal
device(config-ipv6-router-ospf)# area 0
device(config-ipv6-router-ospf)# area 1
device(config)# interface ethernet 1/1 device(config)# enable device(config-ipv6-router-ospf)# ipv6 ospf authentication key-chain keychain2 device(config-ipv6-router-ospf)# ipv6 address 20.20::54/64 device(config-ipv6-router-ospf)# gig-default neg-off
device(config-ipv6-router-ospf)# area 1 virtual-link 3.3.3.3 device(config-ipv6-router-ospf)# area 1 virtual-link 3.3.3.3 authentication key-chain keychain1