CONTAP-324734: LIF down due to IPv6 Duplicate Addres Detection (DAD)

Issue

• When IPv6 Duplicate Addres Detection (DAD) detects a LIFs IPv6 address state is tentative or duplicated the LIF is brought operationaly down to prevent IP conflicts
• EMS:
{}Thu Feb 10 00:57:04 +0000 [Cluster-01: intr: netinet6.nbr.dad.complete:alert]: a0b: DAD complete for xxxx:x::xxxx:xxxx:xxxx:xxxx - duplicate found.{}{}::> net int show -role intercluster -instance{}
    (network interface show)                      Vserver Name: Cluster
            Logical Interface Name: ic_lif
                    Service Policy: default-intercluster
                      Service List: intercluster-core, management-  https,
                                    management-ems
                 (DEPRECATED)-Role: intercluster
                     Data Protocol: none
                   Network Address: xxxx:xxxx:xxx:xxx::xx
                           Netmask: ffff:ffff:ffff:ffff::
               Bits in the Netmask: 64
                        Is VIP LIF: false
                       Subnet Name: -
                         Home Node: Cluster-01
                         Home Port: a0b
                      Current Node: Cluster-01
                      Current Port: a0b
                Operational Status: down
                   Extended Status: This LIF is down because its IPv6 address state is tentative or duplicated.
                           Is Home: true
             Administrative Status: up
                   Failover Policy: local-only
                   Firewall Policy: intercluster
                       Auto Revert: true