IETF Protocol Field in IP Headers

Protocol Numbers

(last updated 2008-04-18)

Registries included below:
- Assigned Internet Protocol Numbers

Registry Name: Assigned Internet Protocol Numbers
Reference: [RFC5237]
Registration Procedures: IESG Approval or Standards Action
Note: 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) [RFC1883], this field
is called the "Next Header" field.

Decimal  Keyword          Protocol                                 References
-------  ---------------  ---------------------------------------  ------------------
0        HOPOPT           IPv6 Hop-by-Hop Option                   [RFC1883]
1        ICMP             Internet Control Message                 [RFC792] 
2        IGMP             Internet Group Management                [RFC1112]
3        GGP              Gateway-to-Gateway                       [RFC823]
4        IP               IP in IP (encapsulation)                 [RFC2003]
5        ST               Stream                                   [RFC1190][RFC1819]
6        TCP              Transmission Control                     [RFC793]
7        CBT              CBT                                      [Ballardie]
8        EGP              Exterior Gateway Protocol                [RFC888][DLM1]
9        IGP              any private interior gateway             [IANA]
                          (used by Cisco for their IGRP)  
10       BBN-RCC-MON      BBN RCC Monitoring                       [SGC]
11       NVP-II           Network Voice Protocol                   [RFC741][SC3]
12       PUP              PUP                                      [PUP][XEROX]
13       ARGUS            ARGUS                                    [RWS4]
14       EMCON            EMCON                                    [BN7]
15       XNET             Cross Net Debugger                       [IEN158][JFH2]
16       CHAOS            Chaos                                    [NC3]
17       UDP              User Datagram                            [RFC768][JBP]
18       MUX              Multiplexing                             [IEN90][JBP]
19       DCN-MEAS         DCN Measurement Subsystems               [DLM1]
20       HMP              Host Monitoring                          [RFC869][RH6]
21       PRM              Packet Radio Measurement                 [ZSU]
22       XNS-IDP          XEROX NS IDP                             [ETHERNET][XEROX]
23       TRUNK-1          Trunk-1                                  [BWB6]
24       TRUNK-2          Trunk-2                                  [BWB6]
25       LEAF-1           Leaf-1                                   [BWB6]
26       LEAF-2           Leaf-2                                   [BWB6]
27       RDP              Reliable Data Protocol                   [RFC908][RH6]
28       IRTP             Internet Reliable Transaction            [RFC938][TXM]
29       ISO-TP4          ISO Transport Protocol Class 4           [RFC905][RC77]
30       NETBLT           Bulk Data Transfer Protocol              [RFC969][DDC1]
31       MFE-NSP          MFE Network Services Protocol            [MFENET][BCH2]
32       MERIT-INP        MERIT Internodal Protocol                [HWB]
33       DCCP             Datagram Congestion Control Protocol     [RFC4340]
34       3PC              Third Party Connect Protocol             [SAF3]
35       IDPR             Inter-Domain Policy Routing Protocol     [MXS1] 
36       XTP              XTP                                      [GXC]
37       DDP              Datagram Delivery Protocol               [WXC]
38       IDPR-CMTP        IDPR Control Message Transport Proto     [MXS1]
39       TP++             TP++ Transport Protocol                  [DXF]
40       IL               IL Transport Protocol                    [Presotto]
41       IPv6             Ipv6                                     [Deering]    
42       SDRP             Source Demand Routing Protocol           [DXE1]
43       IPv6-Route       Routing Header for IPv6                  [Deering]
44       IPv6-Frag        Fragment Header for IPv6                 [Deering]
45       IDRP             Inter-Domain Routing Protocol            [Hares]
46       RSVP             Reservation Protocol                     [Braden]
47       GRE              General Routing Encapsulation            [Li]
48       DSR              Dynamic Source Routing Protocol          [RFC4728]
49       BNA              BNA                                      [Salamon]
50       ESP              Encap Security Payload                   [RFC2406]
51       AH               Authentication Header                    [RFC2402]
52       I-NLSP           Integrated Net Layer Security  TUBA      [GLENN]
53       SWIPE            IP with Encryption                       [JI6]
54       NARP             NBMA Address Resolution Protocol         [RFC1735]
55       MOBILE           IP Mobility                              [Perkins]
56       TLSP             Transport Layer Security Protocol        [Oberg]
                          using Kryptonet key management
57       SKIP             SKIP                                     [Markson]
58       IPv6-ICMP        ICMP for IPv6                            [RFC1883]
59       IPv6-NoNxt       No Next Header for IPv6                  [RFC1883]
60       IPv6-Opts        Destination Options for IPv6             [RFC1883]
61                        any host internal protocol               [IANA]
62       CFTP             CFTP                                     [CFTP][HCF2]
63                        any local network                        [IANA]
64       SAT-EXPAK        SATNET and Backroom EXPAK                [SHB]
65       KRYPTOLAN        Kryptolan                                [PXL1]
66       RVD              MIT Remote Virtual Disk Protocol         [MBG]
67       IPPC             Internet Pluribus Packet Core            [SHB]
68                        any distributed file system              [IANA]
69       SAT-MON          SATNET Monitoring                        [SHB]
70       VISA             VISA Protocol                            [GXT1]
71       IPCV             Internet Packet Core Utility             [SHB]
72       CPNX             Computer Protocol Network Executive      [DXM2]
73       CPHB             Computer Protocol Heart Beat             [DXM2]
74       WSN              Wang Span Network                        [VXD]
75       PVP              Packet Video Protocol                    [SC3]
76       BR-SAT-MON       Backroom SATNET Monitoring               [SHB]
77       SUN-ND           SUN ND PROTOCOL-Temporary                [WM3]
78       WB-MON           WIDEBAND Monitoring                      [SHB]
79       WB-EXPAK         WIDEBAND EXPAK                           [SHB]
80       ISO-IP           ISO Internet Protocol                    [MTR]
81       VMTP             VMTP                                     [DRC3]
82       SECURE-VMTP      SECURE-VMTP                              [DRC3]
83       VINES            VINES                                    [BXH]
84       TTP              TTP                                      [JXS]
85       NSFNET-IGP       NSFNET-IGP                               [HWB]
86       DGP              Dissimilar Gateway Protocol              [DGP][ML109]
87       TCF              TCF                                      [GAL5]
88       EIGRP            EIGRP                                    [CISCO][GXS]
89       OSPFIGP          OSPFIGP                                  [RFC1583][JTM4]
90       Sprite-RPC       Sprite RPC Protocol                      [SPRITE][BXW] 
91       LARP             Locus Address Resolution Protocol        [BXH]
92       MTP              Multicast Transport Protocol             [SXA]
93       AX.25            AX.25 Frames                             [BK29]         
94       IPIP             IP-within-IP Encapsulation Protocol      [JI6]
95       MICP             Mobile Internetworking Control Pro.      [JI6]
96       SCC-SP           Semaphore Communications Sec. Pro.       [HXH]     
97       ETHERIP          Ethernet-within-IP Encapsulation         [RFC3378]
98       ENCAP            Encapsulation Header                     [RFC1241,RXB3]
99                        any private encryption scheme            [IANA]
100      GMTP             GMTP                                     [RXB5]
101      IFMP             Ipsilon Flow Management Protocol         [Hinden]
102      PNNI             PNNI over IP                             [Callon]
103      PIM              Protocol Independent Multicast           [Farinacci]
104      ARIS             ARIS                                     [Feldman]
105      SCPS             SCPS                                     [Durst]
106      QNX              QNX                                      [Hunter]
107      A/N              Active Networks                          [Braden]
108      IPComp           IP Payload Compression Protocol          [RFC2393]
109      SNP              Sitara Networks Protocol                 [Sridhar]
110      Compaq-Peer      Compaq Peer Protocol                     [Volpe]
111      IPX-in-IP        IPX in IP                                [Lee]
112      VRRP             Virtual Router Redundancy Protocol       [RFC3768]
113      PGM              PGM Reliable Transport Protocol          [Speakman]
114                       any 0-hop protocol                       [IANA]
115      L2TP             Layer Two Tunneling Protocol             [Aboba]
116      DDX              D-II Data Exchange (DDX)                 [Worley] 
117      IATP             Interactive Agent Transfer Protocol      [Murphy]
118      STP              Schedule Transfer Protocol               [JMP]
119      SRP              SpectraLink Radio Protocol               [Hamilton]
120      UTI              UTI                                      [Lothberg]
121      SMP              Simple Message Protocol                  [Ekblad]
122      SM               SM                                       [Crowcroft]
123      PTP              Performance Transparency Protocol        [Welzl]
124      ISIS over IPv4                                            [Przygienda]
125      FIRE                                                      [Partridge]
126      CRTP             Combat Radio Transport Protocol          [Sautter]
127      CRUDP            Combat Radio User Datagram               [Sautter]
128      SSCOPMCE                                                  [Waber]
129      IPLT                                                      [Hollbach]
130      SPS              Secure Packet Shield                     [McIntosh] 
131      PIPE             Private IP Encapsulation within IP       [Petri]
132      SCTP             Stream Control Transmission Protocol     [Stewart]
133      FC               Fibre Channel                            [Rajagopal]
134      RSVP-E2E-IGNORE                                           [RFC3175]
135      Mobility Header                                           [RFC3775]
136      UDPLite                                                   [RFC3828]
137      MPLS-in-IP                                                [RFC4023]
138      manet            MANET Protocols                          [RFC-ietf-manet-iana-07.txt]
139      HIP              Host Identity Protocol                   [RFC5201]     
140-252                   Unassigned                               [IANA]
253                       Use for experimentation and testing      [RFC3692] 
254                       Use for experimentation and testing      [RFC3692] 
255      Reserved