Configure IPv6 packet flow labels as the load-balancing hash key

The ipv6-flow-label field in the IPv6 header is not used as the hashing key for load balancing. With this feature support, if you want the load balancing to be based on the flow label of the IPv6 header, include the ipv6-flow-label configuration statement at the [edit forwarding-options hash-key family inet6 layer-3] hierarchy level.