Cisco Systems Cisco Systems Zscaler AT&T Labs, Inc. AT&T Labs, Inc. A single MPLS label or a label stack is advertised along with an address prefix as part of the NLRI belonging to labeled address families such as Labeled Unicast (RFC 8277), VPN (RFC 4364), etc. This document specifies a method to advertise one or more additional, alternative labels for a set of address prefixes using the Next Hop Dependent Characteristics (NHC) attribute.