2026-10-22 2026-10-22 0-247 IETF Review 248-251 Reserved for Experimental Use 252-255 Reserved for Private Use 0 Reserved 1 Do Not Reply 2 Reply via an IPv4/IPv6 UDP Packet 3 Reply via a BIER packet 4-247 Unassigned 248-251 Reserved for Experimental Use 252-255 Reserved for Private Use 0-247 IETF Review 248-251 Reserved for Experimental Use 252-255 Reserved for Private Use 0 No Return Code 1 Malformed Echo Request received 2 One or more of the TLVs is not supported 3 Replying BFR is the only BFER in the BIER header BitString 4 Replying BFR is one of the BFERs in the BIER header BitString 5 Packet-Forward-Success 6 Invalid Multipath Info Request 7 Unassigned 8 No matching entry in the forwarding table 9 Set-Identifier Mismatch 10 DDMAP Mismatch 11-247 Unassigned 248-251 Reserved for Experimental Use 252-255 Reserved for Private Use 0-16383 Standards Action This range is for TLVs and sub-TLVs that require an error message if not recognized. 16384-31739 RFC Required This range is for TLVs and sub-TLVs that require an error message if not recognized. 31740-31743 Reserved for Experimental Use Not to be assigned. 31744-32767 First Come First Served This range is for TLVs and sub-TLVs that require an error message if not recognized. 32768-49161 Standards Action This range is for TLVs and sub-TLVs that can be silently dropped if not recognized. 49162-64507 RFC Required This range is for TLVs and sub-TLVs that can be silently dropped if not recognized. 64508-64511 Reserved for Experimental Use Not to be assigned. 64512-65535 First Come First Served This range is for TLVs and sub-TLVs that can be silently dropped if not recognized. 0 Reserved 1 Original SI-BitString _{No Sub-TLVs} 2 Target SI-BitString _{No Sub-TLVs} 3 Incoming SI-BitString _{No Sub-TLVs} 4 Downstream Detailed Mapping _{Sub-TLVs for TLV Type 4} 5 Responder BFER _{No Sub-TLVs} 6 Responder BFR _{No Sub-TLVs} 7 Ingress Interface _{No Sub-TLVs} 8 Erroneous Echo Request _{No Sub-TLVs} 0 Reserved 1 MPLS Multipath Entropy Data 2 Egress BitString