Internet Assigned Numbers Authority Special-Purpose Multiprotocol Label Switching (MPLS) Label Values Created 2002-11-08 Last Updated 2021-04-14 Available Formats [IMG] XML [IMG] HTML [IMG] Plain text Registries included below * Base Special-Purpose MPLS Label Values * Extended Special-Purpose MPLS Label Values Base Special-Purpose MPLS Label Values Registration Procedure(s) Standards Action Reference [RFC3032][RFC7274][RFC9017] Available Formats [IMG] CSV Value Description Reference 0 IPv4 Explicit NULL Label [RFC3032] 1 Router Alert Label [RFC3032] 2 IPv6 Explicit NULL Label [RFC3032] 3 Implicit NULL Label [RFC3032] 4-6 Unassigned 7 Entropy Label Indicator (ELI) [RFC6790] 8-12 Unassigned 13 Generic Associated Channel Label [RFC5586] 14 OAM Alert Label [RFC3429] 15 Extension Label (XL) [RFC7274][RFC9017] Extended Special-Purpose MPLS Label Values Registration Procedure(s) Standards Action Reference [RFC7274] Available Formats [IMG] CSV Value Description Reference 0-15 Reserved. Never to be made available for allocation. [RFC7274] 16 Metadata Label Indicator (MLI) [RFC8595] 17 Metadata Present Indicator (MPI) [RFC8595] 18-239 Unassigned 240-255 Reserved for Experimental Use [RFC7274] 256-1048575 Reserved. Not to be made available for allocation without a new Standards Track RFC to define an allocation policy. [RFC7274] Licensing Terms