Protocol number
IP is responsible for more than the address that it is most commonly associated with and there are a number of associated protocols that make up the Network Layer. While there are not 256 of them, the field that identifies them is a numeric value between 0 and 256.
In the Internet Protocol version 4 (IPv4) [RFC791] there is a field called “Protocol” to identify the next level protocol. This is an 8 bit field. In Internet Protocol version 6 (IPv6) [RFC2460], this field is called the “Next Header” field.
Protocol numbers
| # | Protocol | Protocol’s Full Name |
| 0 | HOPOPT | IPv6 Hop-by-Hop Option |
| 1 | ICMP | Internet Control Message Protocol |
| 2 | IGMP | Internet Group Management |
| 3 | GGP | Gateway-to-Gateway |
| 4 | IPv4 | IPv4 encapsulation Protocol |
| 5 | ST | Stream |
| 6 | TCP | Transmission Control Protocol |
| 7 | CBT | CBT |
| 8 | EGP | Exterior Gateway Protocol |
| 9 | IGP | Any private interior gateway (used by Cisco for their IGRP) |
| 10 | BBN-RCC-MON | BBN RCC Monitoring |
| 11 | NVP-II | Network Voice Protocol |
| 12 | PUP | PUP |
| # | Protocol | Protocol’s Full Name |
| 13 | ARGUS | ARGUS |
| 14 | EMCON | EMCON |
| 15 | XNET | Cross Net Debugger |
| 16 | CHAOS | Chaos |
| 17 | UDP | User Datagram Protocol |
| 18 | MUX | Multiplexing |
| 19 | DCN-MEAS | DCN Measurement Subsystems |
| 20 | HMP | Host Monitoring |
| 21 | PRM | Packet Radio Measurement |
| 22 | XNS-IDP | XEROX NS IDP |
| 23 | TRUNK-1 | Trunk-1 |
| 24 | TRUNK-2 | Trunk-2 |
| 25 | LEAF-1 | Leaf-1 |
| 26 | LEAF-2 | Leaf-2 |
| 27 | RDP | Reliable Data Protocol |
| 28 | IRTP | Internet Reliable Transaction |
| 29 | ISO-TP4 | ISO Transport Protocol Class 4 |
| 30 | NETBLT | Bulk Data Transfer Protocol |
| 31 | MFE-NSP | MFE Network Services Protocol |
| 32 | MERIT-INP | MERIT Internodal Protocol |
| 33 | DCCP | Datagram Congestion Control Protocol |
| 34 | 3PC | Third Party Connect Protocol |
| 35 | IDPR | Inter-Domain Policy Routing Protocol |
| 36 | XTP | XTP |
| # | Protocol | Protocol’s Full Name |
| 37 | DDP | Datagram Delivery Protocol |
| 38 | IDPR-CMTP | IDPR Control Message Transport Proto |
| 39 | TP++ | TP++ Transport Protocol |
| 40 | IL | IL Transport Protocol |
| 41 | IPv6 | IPv6 encapsulation |
| 42 | IPv6 | SDRPSource Demand Routing Protocol |
| 43 | IPv6-Route | Routing Header for IPv6 |
| 44 | IPv6-Frag | Fragment Header for IPv6 |
| 45 | IDRP | Inter-Domain Routing Protocol |
| 46 | RSVP | Reservation Protocol |
| 47 | GRE | General Routing Encapsulation |
| 48 | DSR | Dynamic Source Routing Protocol |
| 49 | BNA | BNA |
| 50 | ESP | Encap Security Payload |
| 51 | AH | Authentication Header |
| 52 | I-NLSP | Integrated Net Layer Security TUBA |
| 53 | SWIPE | IP with Encryption |
| 54 | NARP | NBMA Address Resolution Protocol |
| 55 | MOBILE | IP Mobility |
| 56 | TLSP | Transport Layer Security Protocol using Kryptonet key management |
| 57 | SKIP | SKIP |
| 58 | IPv6-ICMP | ICMP for IPv6 |
| 59 | IPv6-NoNxt | No Next Header for IPv6 |
| 60 | IPv6-Opts | Destination Options for IPv6 |
| # | Protocol | Protocol’s Full Name |
| 61 | any host internal protocol | |
| 62 | CFTP | CFTP |
| 63 | any local network | |
| 64 | SAT-EXPAK | SATNET and Backroom EXPAK |
| 65 | KRYPTOLAN | Kryptolan |
| 66 | RVD | MIT Remote Virtual Disk Protocol |
| 67 | IPPC | Internet Pluribus Packet Core |
| 68 | any distributed file system | |
| 69 | SAT-MON | SATNET Monitoring |
| 70 | VISA | VISA Protocol |
| 71 | IPCV | Internet Packet Core Utility |
| 72 | CPNX | Computer Protocol Network Executive |
| 73 | CPHB | Computer Protocol Heart Beat |
| 74 | WSN | Wang Span Network |
| 75 | PVP | Packet Video Protocol |
| 76 | BR-SAT-MON | Backroom SATNET Monitoring |
| 77 | SUN-ND | SUN ND PROTOCOL-Temporary |
| 78 | WB-MON | WIDEBAND Monitoring |
| 79 | WB-EXPAK | WIDEBAND EXPAK |
| 80 | ISO-IP | ISO Internet Protocol |
| 81 | VMTP | VMTP |
| 82 | SECURE-VMTP | SECURE-VMTP |
| 83 | VINES | VINES |
| 84 | TTP | TTP |
| # | Protocol | Protocol’s Full Name |
| 84 | IPTM | Protocol Internet Protocol Traffic |
| 85 | NSFNET-IGP | NSFNET-IGP |
| 86 | DGP | Dissimilar Gateway Protocol |
| 87 | TCF | TCF |
| 88 | EIGRP | EIGRP |
| 89 | OSPFIGP | OSPFIGP |
| 90 | Sprite-RPC | Sprite RPC Protocol |
| 91 | LARP | Locus Address Resolution Protocol |
| 92 | MTP | Multicast Transport Protocol |
| 93 | AX.25 | AX.25 Frames |
| 94 | IPIP | IP-within-IP Encapsulation Protocol |
| 95 | MICP | Mobile Internetworking Control Pro. |
| 96 | SCC-SP | Semaphore Communications Sec. Pro. |
| 97 | ETHERIP | Ethernet-within-IP Encapsulation |
| 98 | ENCAP | Encapsulation Header |
| 99 | any private encryption scheme | |
| 100 | GMTP | GMTP |
| 101 | IFMP | Ipsilon Flow Management Protocol |
| 102 | PNNI | PNNI over IP |
| 103 | PIM | Protocol Independent Multicast |
| 104 | ARIS | ARIS |
| 105 | SCPS | SCPS |
| 106 | QNX | QNX |
| 107 | A/N | Active Networks |
| # | Protocol | Protocol’s Full Name | |
| 108 | IPComp | IP Payload Compression Protocol | |
| 109 | SNP | Sitara Networks Protocol | |
| 110 | Compaq-Peer | Compaq Peer Protocol | |
| 111 | IPX-in-IP | IPX in IP | |
| 112 | VRRP | Virtual Router Redundancy Protocol | |
| 113 | PGM | PGM Reliable Transport Protocol | |
| 114 | any 0-hop protocol | ||
| 115 | L2TP | Layer Two Tunneling Protocol | |
| 116 | DDX | D-II Data Exchange (DDX) | |
| 117 | IATP | Interactive Agent Transfer Protocol | |
| 118 | STP | Schedule Transfer Protocol | |
| 119 | SRP | SpectraLink Radio Protocol | |
| 120 | UTI | UTI | |
| 121 | SMP | Simple Message Protocol | |
| 122 | SM | SM | |
| 123 | PTP | Performance Transparency Protocol | |
| 124 | ISIS over IPv4 | ||
| 125 | FIRE | ||
| 126 | CRTP | Combat Radio Transport Protocol | |
| 127 | CRUDP | Combat Radio User Datagram | |
| 128 | SSCOPMCE | ||
| 129 | IPLT | ||
| 130 | SPS | Secure Packet Shield | |
| 131 | PIPE | Private IP Encapsulation within IP | |
| # | Protocol | Protocol’s Full Name | |
| 132 | SCTP | Stream Control Transmission Protocol | |
| 133 | FC | Fibre Channel | |
| 134 | RSVP-E2EIGNORE | ||
| 135 | Mobility Header | ||
| 136 | UDPLite | ||
| 137 | MPLS-in-IP | ||
| 138 | manet | ||
| 139 | HIP | ||
| 140 | Shim6 | ||
| 141 | WESP | ||
| 142 | ROHC | ||
| 143 − 252 | Unassigned | Unassigned | |
| 253 | Use for experimentation and testing | ||
| 254 | Use for experimentation and testing | ||
| 255 | Reserved | ||
Further information can be found by researching RFC 5237.
Protocol number
IP is responsible for more than the address that it is most commonly associated with and there are a number of associated protocols that make up the Network Layer. While there are not 256 of them, the field that identifies them is a numeric value between 0 and 256.
In the Internet Protocol version 4 (IPv4) [RFC791] there is a field called “Protocol” to identify the next level protocol. This is an 8 bit field. In Internet Protocol version 6 (IPv6) [RFC2460], this field is called the “Next Header” field.
Protocol numbers
| # | Protocol | Protocol’s Full Name |
| 0 | HOPOPT | IPv6 Hop-by-Hop Option |
| # | Protocol | Protocol’s Full Name |
| 1 | ICMP | Internet Control Message Protocol |
| 2 | IGMP | Internet Group Management |
| 3 | GGP | Gateway-to-Gateway |
| 4 | IPv4 | IPv4 encapsulation Protocol |
| 5 | ST | Stream |
| 6 | TCP | Transmission Control Protocol |
| 7 | CBT | CBT |
| 8 | EGP | Exterior Gateway Protocol |
| 9 | IGP | Any private interior gateway (used by Cisco for their IGRP) |
| 10 | BBN-RCC-MON | BBN RCC Monitoring |
| 11 | NVP-II | Network Voice Protocol |
| 12 | PUP | PUP |
| 13 | ARGUS | ARGUS |
| 14 | EMCON | EMCON |
| 15 | XNET | Cross Net Debugger |
| 16 | CHAOS | Chaos |
| 17 | UDP | User Datagram Protocol |
| 18 | MUX | Multiplexing |
| 19 | DCN-MEAS | DCN Measurement Subsystems |
| 20 | HMP | Host Monitoring |
| 21 | PRM | Packet Radio Measurement |
| 22 | XNS-IDP | XEROX NS IDP |
| 23 | TRUNK-1 | Trunk-1 |
| 24 | TRUNK-2 | Trunk-2 |
| # | Protocol | Protocol’s Full Name |
| 25 | LEAF-1 | Leaf-1 |
| 26 | LEAF-2 | Leaf-2 |
| 27 | RDP | Reliable Data Protocol |
| 28 | IRTP | Internet Reliable Transaction |
| 29 | ISO-TP4 | ISO Transport Protocol Class 4 |
| 30 | NETBLT | Bulk Data Transfer Protocol |
| 31 | MFE-NSP | MFE Network Services Protocol |
| 32 | MERIT-INP | MERIT Internodal Protocol |
| 33 | DCCP | Datagram Congestion Control Protocol |
| 34 | 3PC | Third Party Connect Protocol |
| 35 | IDPR | Inter-Domain Policy Routing Protocol |
| 36 | XTP | XTP |
| 37 | DDP | Datagram Delivery Protocol |
| 38 | IDPR-CMTP | IDPR Control Message Transport Proto |
| 39 | TP++ | TP++ Transport Protocol |
| 40 | IL | IL Transport Protocol |
| 41 | IPv6 | IPv6 encapsulation |
| 42 | IPv6 | SDRPSource Demand Routing Protocol |
| 43 | IPv6-Route | Routing Header for IPv6 |
| 44 | IPv6-Frag | Fragment Header for IPv6 |
| 45 | IDRP | Inter-Domain Routing Protocol |
| 46 | RSVP | Reservation Protocol |
| 47 | GRE | General Routing Encapsulation |
| 48 | DSR | Dynamic Source Routing Protocol |
| # | Protocol | Protocol’s Full Name |
| 49 | BNA | BNA |
| 50 | ESP | Encap Security Payload |
| 51 | AH | Authentication Header |
| 52 | I-NLSP | Integrated Net Layer Security TUBA |
| 53 | SWIPE | IP with Encryption |
| 54 | NARP | NBMA Address Resolution Protocol |
| 55 | MOBILE | IP Mobility |
| 56 | TLSP | Transport Layer Security Protocol using Kryptonet key management |
| 57 | SKIP | SKIP |
| 58 | IPv6-ICMP | ICMP for IPv6 |
| 59 | IPv6-NoNxt | No Next Header for IPv6 |
| 60 | IPv6-Opts | Destination Options for IPv6 |
| 61 | any host internal protocol | |
| 62 | CFTP | CFTP |
| 63 | any local network | |
| 64 | SAT-EXPAK | SATNET and Backroom EXPAK |
| 65 | KRYPTOLAN | Kryptolan |
| 66 | RVD | MIT Remote Virtual Disk Protocol |
| 67 | IPPC | Internet Pluribus Packet Core |
| 68 | any distributed file system | |
| 69 | SAT-MON | SATNET Monitoring |
| 70 | VISA | VISA Protocol |
| 71 | IPCV | Internet Packet Core Utility |
| 72 | CPNX | Computer Protocol Network Executive |
| # | Protocol | Protocol’s Full Name |
| 73 | CPHB | Computer Protocol Heart Beat |
| 74 | WSN | Wang Span Network |
| 75 | PVP | Packet Video Protocol |
| 76 | BR-SAT-MON | Backroom SATNET Monitoring |
| 77 | SUN-ND | SUN ND PROTOCOL-Temporary |
| 78 | WB-MON | WIDEBAND Monitoring |
| 79 | WB-EXPAK | WIDEBAND EXPAK |
| 80 | ISO-IP | ISO Internet Protocol |
| 81 | VMTP | VMTP |
| 82 | SECURE-VMTP | SECURE-VMTP |
| 83 | VINES | VINES |
| 84 | TTP | TTP |
| 84 | IPTM | Protocol Internet Protocol Traffic |
| 85 | NSFNET-IGP | NSFNET-IGP |
| 86 | DGP | Dissimilar Gateway Protocol |
| 87 | TCF | TCF |
| 88 | EIGRP | EIGRP |
| 89 | OSPFIGP | OSPFIGP |
| 90 | Sprite-RPC | Sprite RPC Protocol |
| 91 | LARP | Locus Address Resolution Protocol |
| 92 | MTP | Multicast Transport Protocol |
| 93 | AX.25 | AX.25 Frames |
| 94 | IPIP | IP-within-IP Encapsulation Protocol |
| 95 | MICP | Mobile Internetworking Control Pro. |
| # | Protocol | Protocol’s Full Name |
| 96 | SCC-SP | Semaphore Communications Sec. Pro. |
| 97 | ETHERIP | Ethernet-within-IP Encapsulation |
| 98 | ENCAP | Encapsulation Header |
| 99 | any private encryption scheme | |
| 100 | GMTP | GMTP |
| 101 | IFMP | Ipsilon Flow Management Protocol |
| 102 | PNNI | PNNI over IP |
| 103 | PIM | Protocol Independent Multicast |
| 104 | ARIS | ARIS |
| 105 | SCPS | SCPS |
| 106 | QNX | QNX |
| 107 | A/N | Active Networks |
| 108 | IPComp | IP Payload Compression Protocol |
| 109 | SNP | Sitara Networks Protocol |
| 110 | Compaq-Peer | Compaq Peer Protocol |
| 111 | IPX-in-IP | IPX in IP |
| 112 | VRRP | Virtual Router Redundancy Protocol |
| 113 | PGM | PGM Reliable Transport Protocol |
| 114 | any 0-hop protocol | |
| 115 | L2TP | Layer Two Tunneling Protocol |
| 116 | DDX | D-II Data Exchange (DDX) |
| 117 | IATP | Interactive Agent Transfer Protocol |
| 118 | STP | Schedule Transfer Protocol |
| 119 | SRP | SpectraLink Radio Protocol |
| # | Protocol | Protocol’s Full Name |
| 120 | UTI | UTI |
| 121 | SMP | Simple Message Protocol |
| 122 | SM | SM |
| 123 | PTP | Performance Transparency Protocol |
| 124 | ISIS over IPv4 | |
| 125 | FIRE | |
| 126 | CRTP | Combat Radio Transport Protocol |
| 127 | CRUDP | Combat Radio User Datagram |
| 128 | SSCOPMCE | |
| 129 | IPLT | |
| 130 | SPS | Secure Packet Shield |
| 131 | PIPE | Private IP Encapsulation within IP |
| 132 | SCTP | Stream Control Transmission Protocol |
| 133 | FC | Fibre Channel |
| 134 | RSVP-E2EIGNORE | |
| 135 | Mobility Header | |
| 136 | UDPLite | |
| 137 | MPLS-in-IP | |
| 138 | manet | |
| 139 | HIP | |
| 140 | Shim6 | |
| 141 | WESP | |
| 142 | ROHC | |
| 143 − 252 | Unassigned | Unassigned |
VPN policies
| # | Protocol | Protocol’s Full Name |
| 253 | Use for experimentation and testing | |
| 254 | Use for experimentation and testing | |
| 255 | Reserved |
Further information can be found by researching RFC 5237.