A higher-layer protocol is identified with an 8-bit field within an IPv4 packet called Protocol. The IPv4 header format is shown in Figure B-1 with the Protocol field shaded. Figure B-2 shows the IPv6 header format where the protocol number is stored in the shaded Next Header field.
Well-known or assigned IP protocols are registered with the Internet Assigned Numbers Authority (IANA). The information presented here is reproduced with permission from the IANA. For the most current IP protocol number assignment information, refer to www.iana.org/numbers.htm under the "Protocol Numbers" link.
Table B-1 shows the registered IP protocol numbers, along with the protocol keyword (or acronym), the name of the protocol, and an RFC number (if applicable).
Table B-1. Registered IP Protocol Numbers, Keywords, Names, and Associated RFCs
Keyword Protocol References | Number |
|---|
HOPOPT IPv6 Hop-by-Hop Option RFC 1883 | 0 |
ICMP Internet Control Message RFC 792 | 1 |
IGMP Internet Group Management RFC 1112 | 2 |
GGP Gateway-to-Gateway RFC 823 | 3 |
IP IP in IP (encapsulation) RFC 2003 | 4 |
ST Stream RFC 1190, RFC 1819 | 5 |
TCP Transmission Control RFC 793 | 6 |
CBT CBT | 7 |
EGP Exterior Gateway Protocol RFC 888 | 8 |
IGP Any private interior gateway IANA (used by Cisco for IGRP) | 9 |
BBN-RCC-MON BBN RCC Monitoring | 10 |
NVP-II Network Voice Protocol RFC 741 | 11 |
PUP PUP | 12 |
ARGUS ARGUS | 13 |
EMCON EMCON | 14 |
XNET Cross Net Debugger | 15 |
CHAOS Chaos | 16 |
UDP User Datagram RFC 768 | 17 |
MUX Multiplexing | 18 |
DCN-MEAS DCN Measurement Subsystems | 19 |
HMP Host Monitoring RFC 869 | 20 |
PRM Packet Radio Measurement | 21 |
XNS-IDP XEROX NS IDP | 22 |
TRUNK-1 Trunk-1 | 23 |
TRUNK-2 Trunk-2 | 24 |
LEAF-1 Leaf-1 | 25 |
LEAF-2 Leaf-2 | 26 |
RDP Reliable Data Protocol RFC 908 | 27 |
IRTP Internet Reliable Transaction RFC 938 | 28 |
ISO-TP4 ISO Transport Protocol Class 4 RFC 905 | 29 |
NETBLT Bulk Data Transfer Protocol RFC 969 | 30 |
MFE-NSP MFE Network Services Protocol | 31 |
MERIT-INP MERIT Internodal Protocol | 32 |
SEP Sequential Exchange Protocol | 33 |
3PC Third Party Connect Protocol | 34 |
IDPR Inter-Domain Policy Routing Protocol RFC 1479 | 35 |
XTP XTP | 36 |
DDP Datagram Delivery Protocol | 37 |
IDPR-CMTP IDPR Control Message Transport Protocol | 38 |
TP++ TP++ Transport Protocol | 39 |
IL IL Transport Protocol | 40 |
IPv6 Ipv6 | 41 |
SDRP Source Demand Routing Protocol | 42 |
IPv6-Route Routing Header for IPv6 | 43 |
IPv6-Frag Fragment Header for IPv6 | 44 |
IDRP Inter-Domain Routing Protocol | 45 |
RSVP Resource ReSerVation Protocol RFC 2205 | 46 |
GRE General Routing Encapsulation RFC 1701 | 47 |
MHRP Mobile Host Routing Protocol | 48 |
BNA BNA | 49 |
ESP Encap Security Payload RFC 2406 | 50 |
AH Authentication Header RFC 2402 | 51 |
I-NLSP Integrated Net Layer Security TUBA | 52 |
SWIPE IP with Encryption | 53 |
NARP NBMA Address Resolution Protocol RFC 1735 | 54 |
MOBILE IP Mobility RFC 2002 | 55 |
TLSP Transport Layer Security Protocol using Kryptonet key management | 56 |
SKIP SKIP | 57 |
IPv6-ICMP ICMP for IPv6 RFC 2463 | 58 |
IPv6-NoNxt No Next Header for IPv6 RFC 2460 | 59 |
IPv6-Opts Destination Options for IPv6 RFC 2460 | 60 |
Any host internal protocol IANA | 61 |
CFTP CFTP | 62 |
Any local network IANA | 63 |
SAT-EXPAK SATNET and Backroom EXPAK | 64 |
KRYPTOLAN Kryptolan | 65 |
RVD MIT Remote Virtual Disk Protocol | 66 |
IPPC Internet Pluribus Packet Core | 67 |
Any distributed file system IANA | 68 |
SAT-MON SATNET Monitoring | 69 |
VISA VISA Protocol | 70 |
IPCV Internet Packet Core Utility | 71 |
CPNX Computer Protocol Network Executive | 72 |
CPHB Computer Protocol Heart Beat | 73 |
WSN Wang Span Network | 74 |
PVP Packet Video Protocol | 75 |
BR-SAT-MON Backroom SATNET Monitoring | 76 |
SUN-ND SUN ND PROTOCOL-Temporary | 77 |
WB-MON WIDEBAND Monitoring | 78 |
WB-EXPAK WIDEBAND EXPAK | 79 |
ISO-IP ISO Internet Protocol | 80 |
VMTP VMTP RFC 1045 | 81 |
SECURE-VMTP SECURE-VMTP | 82 |
VINES VINES | 83 |
TTP TTP | 84 |
NSFNET-IGP NSFNET-IGP | 85 |
DGP Dissimilar Gateway Protocol | 86 |
TCF TCF | 87 |
EIGRP EIGRP CISCO | 88 |
OSPFIGP OSPFIGP RFC 2328 | 89 |
Sprite-RPC Sprite RPC Protocol | 90 |
LARP Locus Address Resolution Protocol | 91 |
MTP Multicast Transport Protocol | 92 |
AX.25 AX.25 Frames | 93 |
IPIP IP-within-IP Encapsulation Protocol RFC 1853 | 94 |
MICP Mobile Internetworking Control Protocol | 95 |
SCC-SP Semaphore Communications Sec. Pro. | 96 |
ETHERIP Ethernet-within-IP Encapsulation | 97 |
ENCAP Encapsulation Header RFC 1241 | 98 |
Any private encryption scheme IANA | 99 |
GMTP GMTP | 100 |
IFMP Ipsilon Flow Management Protocol | 101 |
PNNI PNNI over IP | 102 |
PIM Protocol Independent Multicast RFC 2362 (sparse mode) | 103 |
ARIS ARIS | 104 |
SCPS SCPS | 105 |
QNX QNX | 106 |
A/N Active Networks | 107 |
IPComp IP Payload Compression Protocol RFC 2393 | 108 |
SNP Sitara Networks Protocol | 109 |
Compaq-Peer Compaq Peer Protocol | 110 |
IPX-in-IP IPX in IP RFC 1234 | 111 |
VRRP Virtual Router Redundancy Protocol RFC 2328 | 112 |
PGM PGM Reliable Transport Protocol | 113 |
Any 0-hop protocol IANA | 114 |
L2TP Layer Two Tunneling Protocol RFC 2661 | 115 |
DDX D-II Data Exchange (DDX) | 116 |
IATP Interactive Agent Transfer Protocol | 117 |
STP Schedule Transfer Protocol | 118 |
SRP SpectraLink Radio Protocol | 119 |
UTI UTI | 120 |
SMP Simple Message Protocol | 121 |
SM SM | 122 |
PTP Performance Transparency Protocol | 123 |
ISIS over IPv4 | 124 |
FIRE | 125 |
CRTP Combat Radio Transport Protocol | 126 |
CRUDP Combat Radio User Datagram | 127 |
SSCOPMCE | 128 |
IPLT | 129 |
SPS Secure Packet Shield | 130 |
PIPE Private IP Encapsulation within IP | 131 |
SCTP Stream Control Transmission Protocol | 132 |
FC Fibre Channel | 133 |
Unassigned IANA | 134 to 254 |
Reserved IANA | 255 |