0 HOPOPT, IPv6 Hop-by-Hop Option. RFC 2460 1 ICMP, Internet Control Message Protocol. RFC 792 2 IGAP, IGMP for user Authentication Protocol. 2 IGMP, Internet Group Management Protocol. 2 RGMP, Router-port Group Management Protocol. RFC 1112 3 GGP, Gateway to Gateway Protocol. RFC 823 4 IP in IP encapsulation. RFC 2003 5 ST, Internet Stream Protocol. RFC 1190, RFC 1819 6 TCP, Transmission Control Protocol. RFC 793 7 UCL, CBT. 8 EGP, Exterior Gateway Protocol. RFC 888 9 IGRP, Interior Gateway Routing Protocol. 10 BBN RCC Monitoring. 11 NVP, Network Voice Protocol. RFC 741 12 PUP. 13 ARGUS. 14 EMCON, Emission Control Protocol. 15 XNET, Cross Net Debugger. IEN 158 16 Chaos. 17 UDP, User Datagram Protocol. RFC 768 18 TMux, Transport Multiplexing Protocol. IEN 90 19 DCN Measurement Subsystems. 20 HMP, Host Monitoring Protocol. RFC 869 21 Packet Radio Measurement. 22 XEROX NS IDP. 23 Trunk-1. 24 Trunk-2. 25 Leaf-1. 26 Leaf-2. 27 RDP, Reliable Data Protocol. RFC 908 28 IRTP, Internet Reliable Transaction Protocol. RFC 938 29 ISO Transport Protocol Class 4. RFC 905 30 NETBLT, Network Block Transfer. 31 MFE Network Services Protocol. 32 MERIT Internodal Protocol. 33 DCCP, Datagram Congestion Control Protocol. 34 Third Party Connect Protocol. 35 IDPR, Inter-Domain Policy Routing Protocol. 36 XTP, Xpress Transfer Protocol. 37 Datagram Delivery Protocol. 38 IDPR, Control Message Transport Protocol. 39 TP++ Transport Protocol. 40 IL Transport Protocol. 41 IPv6 over IPv4. RFC 2473 42 SDRP, Source Demand Routing Protocol. 43 IPv6 Routing header. 44 IPv6 Fragment header. 45 IDRP, Inter-Domain Routing Protocol. 46 RSVP, Reservation Protocol. 47 GRE, General Routing Encapsulation. 48 DSR, Dynamic Source Routing Protocol. 49 BNA. 50 ESP, Encapsulating 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 Minimal Encapsulation Protocol. 56 TLSP, Transport Layer Security Protocol using Kryptonet key management. 57 SKIP. 58 ICMPv6, Internet Control Message Protocol for IPv6. 58 MLD, Multicast Listener Discovery. 59 IPv6 No Next Header. 60 IPv6 Destination Options. 61 Any host internal protocol. 62 CFTP. 63 Any local network. 64 SATNET and Backroom EXPAK. 65 Kryptolan. 66 MIT Remote Virtual Disk Protocol. 67 Internet Pluribus Packet Core. 68 Any distributed file system. 69 SATNET Monitoring. 70 VISA Protocol. 71 Internet Packet Core Utility. 72 Computer Protocol Network Executive. 73 Computer Protocol Heart Beat. 74 Wang Span Network. 75 Packet Video Protocol. 76 Backroom SATNET Monitoring. 77 SUN ND PROTOCOL-Temporary. 78 WIDEBAND Monitoring. 79 WIDEBAND EXPAK. 80 ISO-IP. 81 VMTP, Versatile Message Transaction Protocol. 82 SECURE-VMTP 83 VINES. 84 TTP. 85 NSFNET-IGP. 86 Dissimilar Gateway Protocol. 87 TCF. 88 EIGRP. 89 OSPF, Open Shortest Path First Routing Protocol. 89 MOSPF, Multicast Open Shortest Path First. 90 Sprite RPC Protocol. 91 Locus Address Resolution Protocol. 92 MTP, Multicast Transport Protocol. 93 AX.25. 94 IP-within-IP Encapsulation Protocol. 95 Mobile Internetworking Control Protocol. 96 Semaphore Communications Sec. Pro. 97 EtherIP. 98 Encapsulation Header. 99 Any private encryption scheme. 100 GMTP. 101 IFMP, Ipsilon Flow Management Protocol. 102 PNNI over IP. 103 PIM, Protocol Independent Multicast. 104 ARIS. 105 SCPS. 106 QNX. 107 Active Networks. 108 IPPCP, IP Payload Compression Protocol. RFC 2393 109 SNP, Sitara Networks Protocol. 110 Compaq Peer Protocol. 111 IPX in IP. 112 VRRP, Virtual Router Redundancy Protocol. RFC 3768, RFC 5798 113 PGM, Pragmatic General Multicast. 114 any 0-hop protocol. 115 L2TP, Level 2 Tunneling Protocol. RFC 3931 116 DDX, D-II Data Exchange. 117 IATP, Interactive Agent Transfer Protocol. 118 ST, Schedule Transfer. 119 SRP, SpectraLink Radio Protocol. 120 UTI. 121 SMP, Simple Message Protocol. 122 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 Fibre Channel. RFC 6172 134 RSVP-E2E-IGNORE. RFC 3175 135 Mobility Header. RFC 3775 136 UDP-Lite, Lightweight User Datagram Protocol. RFC 3828 137 MPLS in IP. RFC 4023 138 MANET protocols. RFC 5498 139 HIP, Host Identity Protocol. RFC 5201 140 Shim6, Level 3 Multihoming Shim Protocol for IPv6. RFC 5533 141 WESP, Wrapped Encapsulating Security Payload. RFC 5840 142 ROHC, RObust Header Compression. RFC 5858 143-252 empty 253-254 Experimentation and testing. 255 reserved.