This is a list of the IP protocol numbers found in the 8-bit Protocol field of the IPv4 header and the 8-bit Next Header field of the IPv6 header. It is an identifier for the encapsulated protocol and determines the layout of the data that immediately follows the header. Because both fields are eight bits wide, the possible values are limited to the 256 values from 0 (0x00) to 255 (0xFF), of which just over half had been allocated
Protocol numbers are maintained and published by the Internet Assigned Numbers Authority (IANA).
Hex Protocol Number Keyword Protocol References/RFC 0x00 0 HOPOPT IPv6 Hop-by-Hop Option 0x01 1 ICMP Internet Control Message Protocol 0x02 2 IGMP Internet Group Management Protocol 0x03 3 GGP Gateway-to-Gateway Protocol 0x04 4 IP-in-IP IP in IP (encapsulation) 0x05 5 ST Internet Stream Protocol , 0x06 6 TCP Transmission Control Protocol 0x07 7 CBT Core-based trees 0x08 8 EGP Exterior Gateway Protocol 0x09 9 IGP Interior gateway protocol (any private interior gateway, for example Cisco's IGRP) 0x0A 10 BBN-RCC-MON BBN RCC Monitoring 0x0B 11 NVP-II Network Voice Protocol 0x0C 12 PUP Xerox PUP 0x0D 13 ARGUS ARGUS 0x0E 14 EMCON EMCON 0x0F 15 XNET Cross Net Debugger IEN 158 0x10 16 CHAOS Chaos 0x11 17 UDP User Datagram Protocol 0x12 18 MUX Multiplexing IEN 90 0x13 19 DCN-MEAS DCN Measurement Subsystems 0x14 20 HMP Host Monitoring Protocol 0x15 21 PRM Packet Radio Measurement 0x16 22 XNS-IDP XEROX NS IDP 0x17 23 TRUNK-1 Trunk-1 0x18 24 TRUNK-2 Trunk-2 0x19 25 LEAF-1 Leaf-1 0x1A 26 LEAF-2 Leaf-2 0x1B 27 RDP Reliable Data Protocol 0x1C 28 IRTP Internet Reliable Transaction Protocol 0x1D 29 ISO-TP4 ISO Transport Protocol Class 4 0x1E 30 NETBLT Bulk Data Transfer Protocol 0x1F 31 MFE-NSP MFE Network Services Protocol 0x20 32 MERIT-INP MERIT Internodal Protocol 0x21 33 DCCP Datagram Congestion Control Protocol 0x22 34 3PC Third Party Connect Protocol 0x23 35 IDPR Inter-Domain Policy Routing Protocol 0x24 36 XTP Xpress Transport Protocol 0x25 37 DDP Datagram Delivery Protocol 0x26 38 IDPR-CMTP IDPR Control Message Transport Protocol 0x27 39 TP++ TP++ Transport Protocol 0x28 40 IL IL Transport Protocol 0x29 41 IPv6 IPv6 Encapsulation (6to4 and 6in4) 0x2A 42 SDRP Source Demand Routing Protocol 0x2B 43 IPv6-Route Routing Header for IPv6 0x2C 44 IPv6-Frag Fragment Header for IPv6 0x2D 45 IDRP Inter-Domain Routing Protocol 0x2E 46 RSVP Resource Reservation Protocol 0x2F 47 GRE Generic Routing Encapsulation , 0x30 48 DSR Dynamic Source Routing Protocol 0x31 49 BNA Burroughs Network Architecture 0x32 50 ESP Encapsulating Security Payload 0x33 51 AH Authentication Header 0x34 52 I-NLSP Integrated Net Layer Security Protocol TUBA 0x35 53 SwIPe SwIPe 0x36 54 NARP NBMA Address Resolution Protocol 0x37 55 MOBILE IP Mobility (Min Encap) 0x38 56 TLSP Transport Layer Security Protocol (using Kryptonet key management) 0x39 57 SKIP Simple Key-Management for Internet Protocol 0x3A 58 IPv6-ICMP ICMP for IPv6 , 0x3B 59 IPv6-NoNxt No Next Header for IPv6 0x3C 60 IPv6-Opts Destination Options for IPv6 0x3D 61 Any host internal protocol 0x3E 62 CFTP CFTP 0x3F 63 Any local network 0x40 64 SAT-EXPAK SATNET and Backroom EXPAK 0x41 65 KRYPTOLAN Kryptolan 0x42 66 RVD MIT Remote Virtual Disk Protocol 0x43 67 IPPC Internet Pluribus Packet Core 0x44 68 Any distributed file system 0x45 69 SAT-MON SATNET Monitoring 0x46 70 VISA VISA Protocol 0x47 71 IPCU Internet Packet Core Utility 0x48 72 CPNX Computer Protocol Network Executive 0x49 73 CPHB Computer Protocol Heart Beat 0x4A 74 WSN Wang Span Network 0x4B 75 PVP Packet Video Protocol 0x4C 76 BR-SAT-MON Backroom SATNET Monitoring 0x4D 77 SUN-ND SUN ND PROTOCOL-Temporary 0x4E 78 WB-MON WIDEBAND Monitoring 0x4F 79 WB-EXPAK WIDEBAND EXPAK 0x50 80 ISO-IP International Organization for Standardization Internet Protocol 0x51 81 VMTP Versatile Message Transaction Protocol 0x52 82 SECURE-VMTP Secure Versatile Message Transaction Protocol 0x53 83 VINES VINES 0x54 84 TTP TTP (Transaction Transport Protocol) (obsoleted March 2023) 0x54 84 IPTM Internet Protocol Traffic Manager 0x55 85 NSFNET-IGP NSFNET-IGP 0x56 86 DGP Dissimilar Gateway Protocol 0x57 87 TCF TCF 0x58 88 EIGRP EIGRP Informational 0x59 89 OSPF Open Shortest Path First 0x5A 90 Sprite-RPC Sprite RPC Protocol 0x5B 91 LARP Locus Address Resolution Protocol 0x5C 92 MTP Multicast Transport Protocol 0x5D 93 AX.25 AX.25 0x5E 94 OS KA9Q NOS compatible IP over IP tunneling 0x5F 95 MICP Mobile Internetworking Control Protocol 0x60 96 SCC-SP Semaphore Communications Sec. Pro 0x61 97 ETHERIP Ethernet-within-IP Encapsulation 0x62 98 ENCAP Encapsulation Header 0x63 99 Any private encryption scheme 0x64 100 GMTP GMTP 0x65 101 IFMP Ipsilon Flow Management Protocol 0x66 102 PNNI PNNI over IP 0x67 103 PIM Protocol Independent Multicast 0x68 104 ARIS IBM's ARIS (Aggregate Route IP Switching) Protocol 0x69 105 SCPS SCPS (Space Communications Protocol Standards) SCPS-TP 0x6A 106 QNX QNX 0x6B 107 A/N Active Networks 0x6C 108 IPComp IP Payload Compression Protocol 0x6D 109 SNP Sitara Networks Protocol 0x6E 110 Compaq-Peer Compaq Peer Protocol 0x6F 111 IPX-in-IP IPX in IP 0x70 112 VRRP Virtual Router Redundancy Protocol, Common Address Redundancy Protocol (not IANA assigned) 0x71 113 PGM PGM Reliable Transport Protocol 0x72 114 Any 0-hop protocol 0x73 115 L2TP Layer Two Tunneling Protocol Version 3 0x74 116 DDX D-II Data Exchange (DDX) 0x75 117 IATP Interactive Agent Transfer Protocol 0x76 118 STP Schedule Transfer Protocol 0x77 119 SRP SpectraLink Radio Protocol 0x78 120 UTI Universal Transport Interface Protocol 0x79 121 SMP Simple Message Protocol 0x7A 122 SM Simple Multicast Protocol draft-perlman-simple-multicast-03 0x7B 123 PTP Performance Transparency Protocol 0x7C 124 IS-IS over IPv4 Intermediate System to Intermediate System (IS-IS) Protocol over IPv4 and 0x7D 125 FIRE Flexible Intra-AS Routing Environment 0x7E 126 CRTP Combat Radio Transport Protocol 0x7F 127 CRUDP Combat Radio User Datagram 0x80 128 SSCOPMCE Service-Specific Connection-Oriented Protocol in a Multilink and Connectionless Environment ITU-T Q.2111 (1999) 0x81 129 IPLT 0x82 130 SPS Secure Packet Shield 0x83 131 PIPE Private IP Encapsulation within IP Expired I-D draft-petri-mobileip-pipe-00.txt 0x84 132 SCTP Stream Control Transmission Protocol 0x85 133 FC Fibre Channel 0x86 134 RSVP-E2E-IGNORE Reservation Protocol (RSVP) End-to-End Ignore 0x87 135 Mobility Header Mobility Extension Header for IPv6 0x88 136 UDPLite Lightweight User Datagram Protocol 0x89 137 MPLS-in-IP Multiprotocol Label Switching Encapsulated in IP , 0x8A 138 manet MANET Protocols 0x8B 139 HIP Host Identity Protocol 0x8C 140 Shim6 Site Multihoming by IPv6 Intermediation 0x8D 141 WESP Wrapped Encapsulating Security Payload 0x8E 142 ROHC Robust Header Compression 0x8F 143 Ethernet Segment Routing over IPv6 0x90 144 AGGFRAG AGGFRAG Encapsulation Payload for ESP 0x91 145 NSH Network Service Header draft-ietf-spring-nsh-sr 0x92 146 Homa Homa transport protocol Homa research paper, HomaModule 0x93 147 BIT-EMU Bit-stream Emulation 0x94-0xFC 148-252 Unassigned 0xFD-0xFE 253-254 Use for experimentation and testing 0xFF 255 Reserved
See also EtherType Internet Protocol IPv4 (including packet structure) IPv6 (and packet structure)
References