What caused this issue?

For security purposes, an IPv6 traffic filter was configured under various interfaces on the local router.

However, shortly after implementing the traffic filter, OSPFv3 neighbor adjacencies were lost.

What caused this issue?
A . The traffic filter is blocking all ICMPv6 traffic.
B . The global anycast address must be added to the traffic filter to allow OSPFv3 to work properly.
C . The link-local addresses that were used by OSPFv3 were explicitly denied, which caused the neighbor relationships to fail.
D . IPv6 traffic filtering can be implemented only on SVIs.

Answer: C

Explanation:

OSPFv3 uses link-local Ipv6 addresses for neighbor discovery and other features, so if any Ipv6 traffic filters are implemented be sure to include the link local address so that it is permitted in the filter list.

Reference: http://www.cisco.com/c/en/us/td/docs/switches/datacenter/sw/5_x/nx-os/unicast/configuration/ guide/l3_cli_nxos/l3_ospfv3.html