Sets the DHCPv6 trust role for this interface within the MPLS VS -- clientTrust, serverTrust, dualRoleTrust, or unTrust. Because MPLS-based services often carry aggregated traffic across a pseudowire rather than a single physical access port, this trust setting applies at the interface level for that pseudowire's traffic, which needs to be configured just as carefully as a VLAN access port to prevent rogue DHCPv6 servers from responding across the MPLS core. An interface carrying traffic toward the actual DHCPv6 server across the MPLS network would be set to serverTrust, while customer-facing interfaces on the same VS remain clientTrust.