Network Working Group G. Harris, Ed. Internet-Draft Intended status: Informational M. Richardson Expires: 3 September 2026 Sandelman 2 March 2026 Link-Layer Types for PCAP-related Capture File Formats draft-ietf-opsawg-pcaplinktype-17 Abstract This document describes a set of Packet CAPture (PCAP)-related LinkType values and creates an IANA registry for those values. These values are used by the PCAP and PCAP-Now-Generic specifications. About This Document This note is to be removed before publishing as an RFC. Status information for this document may be found at https://datatracker.ietf.org/doc/draft-ietf-opsawg-pcaplinktype/. Discussion of this document takes place on the opsawg Working Group mailing list (mailto:opsawg@ietf.org), which is archived at https://mailarchive.ietf.org/arch/browse/opsawg/. Subscribe at https://www.ietf.org/mailman/listinfo/opsawg/. Source for this draft and an issue tracker can be found at https://github.com/IETF-OPSAWG-WG/pcapng. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on 3 September 2026. Harris & Richardson Expires 3 September 2026 [Page 1] Internet-Draft pcaplinktype March 2026 Copyright Notice Copyright (c) 2026 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/ license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3 2.1. PCAP Registry . . . . . . . . . . . . . . . . . . . . . . 3 2.2. LinkType Registry . . . . . . . . . . . . . . . . . . . . 3 2.2.1. Initial Values . . . . . . . . . . . . . . . . . . . 4 2.2.2. Guidance for Designated Experts . . . . . . . . . . . 25 3. Security Considerations . . . . . . . . . . . . . . . . . . . 26 4. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 26 5. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 26 6. References . . . . . . . . . . . . . . . . . . . . . . . . . 26 6.1. Normative References . . . . . . . . . . . . . . . . . . 26 6.2. Informative References . . . . . . . . . . . . . . . . . 26 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 38 1. Introduction In the late 1980s, Van Jacobson, Steve McCanne, and others at the Network Research Group at Lawrence Berkeley National Laboratory developed the tcpdump program to capture and dissect network traces. The code to capture traffic, using low-level mechanisms in various operating systems, and to read and write network traces to a file was later put into a library named libpcap [LIBPCAP]. Other documents describe the original (legacy) file format used by tcpdump (PCAP, [I-D.ietf-opsawg-pcap]), as well as a revised file format [I-D.ietf-opsawg-pcapng], both of which are used by tcpdump and Wireshark [Wireshark]. Within those file formats each packet that is captured is indicated by a LinkType value. The LinkType value selects one of many hundred formats for metadata and Layer 2 encapsulation of the packet. Harris & Richardson Expires 3 September 2026 [Page 2] Internet-Draft pcaplinktype March 2026 This document creates an IANA registry for LinkType values, establishing the IANA Considerations by which other uses of the PCAP- related formats may register new LinkType values. 2. IANA Considerations 2.1. PCAP Registry IANA is requested to create a new registry group entitled "The PCAP Registry". 2.2. LinkType Registry IANA is also requested to create a registry entitled "PCAP-related LinkType List" under The PCAP registry group (Section 2.1). The registry has the following structure: * LinkType Value: Indicates the 16-bit unsigned integer assigned for this LinkType. * LinkType Name: Indicates the symbolic name for this LinkType. The name is prefixed with "LINKTYPE_" (i.e., LINKTYPE_something). * Change Controller: as per [RFC8126], Section 2.3 * Description: Provides a very short description. * Reference: Indicates an authoritative document reference for the LinkType or a requester reference. The policy allocation for the LinkType values is as follows: * Values from 0 to 65000 are allocated following an Expert Review policy (Section 4.5 of [RFC8126]). Values in the ranges 0-10, 50-51, and 98-301 are already assigned; values in the ranges 11-49 and 52-97 are reserved and must not be assigned. * Values from 65001 to 65535 are reserved for Experimental Use (Section 4.2 of [RFC8126]). The initial version of the registry is provided in Section 2.2.1. In each case here, the reference should be set to [LINKTYPES] and the RFC number to be assigned to this document, which is not repeated each time. Harris & Richardson Expires 3 September 2026 [Page 3] Internet-Draft pcaplinktype March 2026 The initial contents of the table are based upon the link-layer header type list maintained by libpcap, and published on [LINKTYPES]. The change controller for all initial entries that have no other reference is linktype@tcpdump.org. LinkType values 147 to 162 named LINKTYPE_RESERVED_xx were originally reserved for Experimental/Private Use, and that use continues to be supported. However, new private use cases should use the values in the 65001-65535 range. In general, Experimental Use values should never leak out of the entity that uses it. As the FCFS range is large and easily obtained, official values are recommended. There is often an associated Data Link Type (DLT) value which is often identical in value, but not universally so. DLT values are associated with specific operating systems, and the numerical values for some of them are operating system specific, and are thus not subject to standardization. 2.2.1. Initial Values This is the initial table for the registry: LinkType Value 0 LinkType Name LINKTYPE_NULL Description BSD loopback encapsulation Reference [LINKTYPE_NULL] LinkType Value 1 LinkType Name LINKTYPE_ETHERNET Description IEEE 802.3 Ethernet Reference [LINKTYPE_ETHERNET] LinkType Value 2 LinkType Name LINKTYPE_EXP_ETHERNET Description Xerox experimental 3Mb Ethernet Reference [PracConsEthDesign] LinkType Value 3 LinkType Name LINKTYPE_AX25 Description AX.25 layer 2 packets Reference [LINKTYPE_AX25] LinkType Value 4 LinkType Name LINKTYPE_PRONET Description Proteon PRONet Token Ring Harris & Richardson Expires 3 September 2026 [Page 4] Internet-Draft pcaplinktype March 2026 LinkType Value 5 LinkType Name LINKTYPE_CHAOS Description MIT Chaosnet Reference [AIM-628] LinkType Value 6 LinkType Name LINKTYPE_IEEE802_5 Description IEEE 802.5 Token Ring LinkType Value 7 LinkType Name LINKTYPE_ARCNET_BSD Description ARCNET Data Packets with BSD encapsulation LinkType Value 8 LinkType Name LINKTYPE_SLIP Description SLIP, with a direction header Reference [LINKTYPE_SLIP] LinkType Value 9 LinkType Name LINKTYPE_PPP Description PPP Reference [LINKTYPE_PPP] LinkType Value 10 LinkType Name LINKTYPE_FDDI Description FDDI: per ANSI INCITS 239-1994 LinkType Value 11-49 LinkType Name Not available for assignment Description Do not use these values LinkType Value 50 LinkType Name LINKTYPE_PPP_HDLC Description PPP in HDLC-like framing Reference [LINKTYPE_PPP_HDLC] LinkType Value 51 LinkType Name LINKTYPE_PPP_ETHER Description PPPoE session packets Reference [LINKTYPE_PPP_ETHER] LinkType Value 52-98 LinkType Name Not available for assignment Description Used historically by NetBSD LinkType Value 99 LinkType Name LINKTYPE_SYMANTEC_FIREWALL Description Symantec Enterprise Firewall Harris & Richardson Expires 3 September 2026 [Page 5] Internet-Draft pcaplinktype March 2026 LinkType Value 100 LinkType Name LINKTYPE_ATM_RFC1483 Description LLC/SNAP-encapsulated ATM Reference [LINKTYPE_ATM_RFC1483] LinkType Value 101 LinkType Name LINKTYPE_RAW Description IP without link-layer headers Reference [LINKTYPE_RAW] [RFC791] [RFC8200] LinkType Value 102 LinkType Name LINKTYPE_SLIP_BSDOS Description BSD/OS SLIP BPF header LinkType Value 103 LinkType Name LINKTYPE_PPP_BSDOS Description BSD/OS PPP BPF header LinkType Value 104 LinkType Name LINKTYPE_C_HDLC Description Cisco PPP with HDLC framing Reference [LINKTYPE_C_HDLC] LinkType Value 105 LinkType Name LINKTYPE_IEEE802_11 Description IEEE 802.11 wireless LAN LinkType Value 106 LinkType Name LINKTYPE_ATM_CLIP Description ATM Classical IP, with no header preceding IP LinkType Value 107 LinkType Name LINKTYPE_FRELAY Description Frame Relay LAPF Reference [LINKTYPE_FRELAY] LinkType Value 108 LinkType Name LINKTYPE_LOOP Description OpenBSD loopback encapsulation Reference [LINKTYPE_LOOP] LinkType Value 109 LinkType Name LINKTYPE_ENC Description OpenBSD IPsec encapsulation LinkType Value 110 LinkType Name LINKTYPE_LANE8023 Description ATM LANE + 802.3 Harris & Richardson Expires 3 September 2026 [Page 6] Internet-Draft pcaplinktype March 2026 LinkType Value 111 LinkType Name LINKTYPE_HIPPI Description NetBSD HIPPI LinkType Value 112 LinkType Name LINKTYPE_HDLC Description NetBSD HDLC framing LinkType Value 113 LinkType Name LINKTYPE_LINUX_SLL Description Linux "cooked" capture encapsulation Reference [LINKTYPE_LINUX_SLL] LinkType Value 114 LinkType Name LINKTYPE_LTALK Description Apple LocalTalk Reference [LINKTYPE_LTALK] LinkType Value 115 LinkType Name LINKTYPE_ECONET Description Acorn Econet LinkType Value 116 LinkType Name LINKTYPE_IPFILTER Description OpenBSD ipfilter LinkType Value 117 LinkType Name LINKTYPE_PFLOG Description PF packet filter logging LinkType Value 118 LinkType Name LINKTYPE_CISCO_IOS Description Cisco-internal use LinkType Value 119 LinkType Name LINKTYPE_IEEE802_11_PRISM Description IEEE 802.11 wireless LAN, preceded by a Prism monitor mode header Reference [LINKTYPE_IEEE802_11_PRISM] LinkType Value 120 LinkType Name LINKTYPE_IEEE802_11_AIRONET Description 802.11 + FreeBSD Aironet radio metadata LinkType Value 121 LinkType Name LINKTYPE_HHDLC Description Siemens HiPath HDLC Harris & Richardson Expires 3 September 2026 [Page 7] Internet-Draft pcaplinktype March 2026 LinkType Value 122 LinkType Name LINKTYPE_IP_OVER_FC Description IP and ATM over Fibre Channel Reference [LINKTYPE_IP_OVER_FC] LinkType Value 123 LinkType Name LINKTYPE_SUNATM Description ATM traffic captured from a SunATM device Reference [LINKTYPE_SUNATM] LinkType Value 124 LinkType Name LINKTYPE_RIO Description RapidIO LinkType Value 125 LinkType Name LINKTYPE_PCI_EXP Description PCI Express LinkType Value 126 LinkType Name LINKTYPE_AURORA Description Xilinx Aurora link layer LinkType Value 127 LinkType Name LINKTYPE_IEEE802_11_RADIOTAP Description IEEE 802.11 wireless LAN, preceded by a Radiotap header Reference [Radiotap] LinkType Value 128 LinkType Name LINKTYPE_TZSP Description Tazmen Sniffer Protocol LinkType Value 129 LinkType Name LINKTYPE_ARCNET_LINUX Description ARCNET Data Packets with Linux encapsulation LinkType Value 130 LinkType Name LINKTYPE_JUNIPER_MLPPP Description Juniper Networks LinkType Value 131 LinkType Name LINKTYPE_JUNIPER_MLFR Description Juniper Networks LinkType Value 132 LinkType Name LINKTYPE_JUNIPER_ES Description Juniper Networks LinkType Value 133 Harris & Richardson Expires 3 September 2026 [Page 8] Internet-Draft pcaplinktype March 2026 LinkType Name LINKTYPE_JUNIPER_GGSN Description Juniper Networks LinkType Value 134 LinkType Name LINKTYPE_JUNIPER_MFR Description Juniper Networks LinkType Value 135 LinkType Name LINKTYPE_JUNIPER_ATM2 Description Juniper Networks LinkType Value 136 LinkType Name LINKTYPE_JUNIPER_SERVICES Description Juniper Networks LinkType Value 137 LinkType Name LINKTYPE_JUNIPER_ATM1 Description Juniper Networks LinkType Value 138 LinkType Name LINKTYPE_APPLE_IP_OVER_IEEE1394 Description Apple IP-over-IEEE 1394 cooked header Reference [LINKTYPE_APPLE_IP_OVER_IEEE1394] LinkType Value 139 LinkType Name LINKTYPE_MTP2_WITH_PHDR Description SS7 MTP2 frames, with a pseudo-header Reference [LINKTYPE_MTP2_WITH_PHDR] LinkType Value 140 LinkType Name LINKTYPE_MTP2 Description SS7 MTP2 packets Reference [LINKTYPE_MTP2] LinkType Value 141 LinkType Name LINKTYPE_MTP3 Description SS7 MTP3 packets Reference [LINKTYPE_MTP3] LinkType Value 142 LinkType Name LINKTYPE_SCCP Description SS7 SCCP packets Reference [LINKTYPE_SCCP] LinkType Value 143 LinkType Name LINKTYPE_DOCSIS Description DOCSIS MAC frames Reference [DOCSIS-4.0-MULP] Harris & Richardson Expires 3 September 2026 [Page 9] Internet-Draft pcaplinktype March 2026 LinkType Value 144 LinkType Name LINKTYPE_LINUX_IRDA Description Linux-IrDA packets Reference [LINKTYPE_LINUX_IRDA] LinkType Value 145 LinkType Name LINKTYPE_IBM_SP Description IBM SP switch LinkType Value 146 LinkType Name LINKTYPE_IBM_SN Description IBM Next Federation switch LinkType Value 147 LinkType Name LINKTYPE_RESERVED_01 Description For private use (deprecated) LinkType Value 148 LinkType Name LINKTYPE_RESERVED_02 Description For private use (deprecated) LinkType Value 149 LinkType Name LINKTYPE_RESERVED_03 Description For private use (deprecated) LinkType Value 150 LinkType Name LINKTYPE_RESERVED_04 Description For private use (deprecated) LinkType Value 151 LinkType Name LINKTYPE_RESERVED_05 Description For private use (deprecated) LinkType Value 152 LinkType Name LINKTYPE_RESERVED_06 Description For private use (deprecated) LinkType Value 153 LinkType Name LINKTYPE_RESERVED_07 Description For private use (deprecated) LinkType Value 154 LinkType Name LINKTYPE_RESERVED_08 Description For private use (deprecated) LinkType Value 155 LinkType Name LINKTYPE_RESERVED_09 Description For private use (deprecated) Harris & Richardson Expires 3 September 2026 [Page 10] Internet-Draft pcaplinktype March 2026 LinkType Value 156 LinkType Name LINKTYPE_RESERVED_10 Description For private use (deprecated) LinkType Value 157 LinkType Name LINKTYPE_RESERVED_11 Description For private use (deprecated) LinkType Value 158 LinkType Name LINKTYPE_RESERVED_12 Description For private use (deprecated) LinkType Value 159 LinkType Name LINKTYPE_RESERVED_13 Description For private use (deprecated) LinkType Value 160 LinkType Name LINKTYPE_RESERVED_14 Description For private use (deprecated) LinkType Value 161 LinkType Name LINKTYPE_RESERVED_15 Description For private use (deprecated) LinkType Value 162 LinkType Name LINKTYPE_RESERVED_16 Description For private use (deprecated) LinkType Value 163 LinkType Name LINKTYPE_IEEE802_11_AVS Description IEEE 802.11 wireless LAN, preceded by an AVS header Reference [AVS] LinkType Value 164 LinkType Name LINKTYPE_JUNIPER_MONITOR Description Juniper Networks LinkType Value 165 LinkType Name LINKTYPE_BACNET_MS_TP Description BACnet MS/TP frames Reference [LINKTYPE_BACNET_MS_TP] LinkType Value 166 LinkType Name LINKTYPE_PPP_PPPD Description PPP preceded by a direction octet and an HDLC-like control field Reference [LINKTYPE_PPP_PPPD] Harris & Richardson Expires 3 September 2026 [Page 11] Internet-Draft pcaplinktype March 2026 LinkType Value 167 LinkType Name LINKTYPE_JUNIPER_PPPOE Description Juniper Networks LinkType Value 168 LinkType Name LINKTYPE_JUNIPER_PPPOE_ATM Description Juniper Networks LinkType Value 169 LinkType Name LINKTYPE_GPRS_LLC Description General Packet Radio Service Logical Link Control, as per 3GPP TS 04.64 Reference [_3GPP-TS-04.64] LinkType Value 170 LinkType Name LINKTYPE_GPF_T Description Transparent-mapped generic framing procedure Reference [G.7041] LinkType Value 171 LinkType Name LINKTYPE_GPF_F Description Frame-mapped generic framing procedure Reference [G.7041] LinkType Value 172 LinkType Name LINKTYPE_GCOM_T1E1 Description Gcom T1/E1 line monitoring equipment LinkType Value 173 LinkType Name LINKTYPE_GCOM_SERIAL Description Gcom T1/E1 line monitoring equipment LinkType Value 174 LinkType Name LINKTYPE_JUNIPER_PIC_PEER Description Juniper Networks LinkType Value 175 LinkType Name LINKTYPE_ERF_ETH Description Endace TYPE_ETH ERF records Reference [LINKTYPE_ERF] LinkType Value 176 LinkType Name LINKTYPE_ERF_POS Description Endace TYPE_POS_HDLC ERF records Reference [LINKTYPE_ERF] LinkType Value 177 LinkType Name LINKTYPE_LINUX_LAPD Harris & Richardson Expires 3 September 2026 [Page 12] Internet-Draft pcaplinktype March 2026 Description Linux vISDN LAPD frames Reference [LINKTYPE_LINUX_LAPD] LinkType Value 178 LinkType Name LINKTYPE_JUNIPER_ETHER Description Juniper Networks LinkType Value 179 LinkType Name LINKTYPE_JUNIPER_PPP Description Juniper Networks LinkType Value 180 LinkType Name LINKTYPE_JUNIPER_FRELAY Description Juniper Networks LinkType Value 181 LinkType Name LINKTYPE_JUNIPER_CHDLC Description Juniper Networks LinkType Value 182 LinkType Name LINKTYPE_MFR Description FRF.16.1 Multi-Link Frame Relay frames Reference [LINKTYPE_MFR] LinkType Value 183 LinkType Name LINKTYPE_JUNIPER_VP Description Juniper Networks LinkType Value 184 LinkType Name LINKTYPE_A429 Description ARINC 429 frames LinkType Value 185 LinkType Name LINKTYPE_A653_ICM Description Arinc 653 Interpartition Communication messages LinkType Value 186 LinkType Name LINKTYPE_USB_FREEBSD Description USB traffic captured on FreeBSD LinkType Value 187 LinkType Name LINKTYPE_BLUETOOTH_HCI_H4 Description Bluetooth HCI UART Transport Layer packets Reference [LINKTYPE_BLUETOOTH_HCI_H4] LinkType Value 188 LinkType Name LINKTYPE_IEEE802_16_MAC_CPS Description IEEE 802.16 MAC Common Part Sublayer Harris & Richardson Expires 3 September 2026 [Page 13] Internet-Draft pcaplinktype March 2026 LinkType Value 189 LinkType Name LINKTYPE_USB_LINUX Description USB packets, beginning with a Linux USB header Reference [LINKTYPE_USB_LINUX] LinkType Value 190 LinkType Name LINKTYPE_CAN20B Description Controller Area Network (CAN) v. 2.0B packets LinkType Value 191 LinkType Name LINKTYPE_IEEE802_15_4_LINUX Description IEEE 802.15.4 with address fields padded by Linux LinkType Value 192 LinkType Name LINKTYPE_PPI Description Per-Packet Information header preceding packet data Reference [LINKTYPE_PPI] LinkType Value 193 LinkType Name LINKTYPE_IEEE802_16_MAC_CPS_RADIO Description 802.16 MAC Common Part Sublayer plus radio header LinkType Value 194 LinkType Name LINKTYPE_JUNIPER_ISM Description Juniper Networks LinkType Value 195 LinkType Name LINKTYPE_IEEE802_15_4_WITHFCS Description IEEE 802.15.4 with FCS Reference [LINKTYPE_IEEE802_15_4_WITHFCS] LinkType Value 196 LinkType Name LINKTYPE_SITA Description Various link-layer types, with a pseudo-header Reference [LINKTYPE_SITA] LinkType Value 197 LinkType Name LINKTYPE_ERF Description Endace ERF records Reference [LINKTYPE_ERF] LinkType Value 198 LinkType Name LINKTYPE_RAIF1 Description Ethernet packets captured from a u10 Networks board LinkType Value 199 LinkType Name LINKTYPE_IPMB_KONTRON Description IPMB packet for IPMI, with a 2-octet header Harris & Richardson Expires 3 September 2026 [Page 14] Internet-Draft pcaplinktype March 2026 LinkType Value 200 LinkType Name LINKTYPE_JUNIPER_ST Description Juniper Networks LinkType Value 201 LinkType Name LINKTYPE_BLUETOOTH_HCI_H4_WITH_PHDR Description Bluetooth HCI UART Transport Layer packets with a direction pseudo-header Reference [LINKTYPE_BLUETOOTH_HCI_H4_WITH_PHDR] LinkType Value 202 LinkType Name LINKTYPE_AX25_KISS Description KISS frames between a host and an AX.25 TNC Reference [LINKTYPE_AX25_KISS] LinkType Value 203 LinkType Name LINKTYPE_LAPD Description Q.921 LAPD frames Reference [LINKTYPE_LAPD] LinkType Value 204 LinkType Name LINKTYPE_PPP_WITH_DIR Description PPP, with a direction header Reference [LINKTYPE_PPP_WITH_DIR] LinkType Value 205 LinkType Name LINKTYPE_C_HDLC_WITH_DIR Description Cisco PPP with HDLC framing, with a direction header Reference [LINKTYPE_C_HDLC_WITH_DIR] LinkType Value 206 LinkType Name LINKTYPE_FRELAY_WITH_DIR Description Frame Relay LAPF, with a direction header Reference [LINKTYPE_FRELAY_WITH_DIR] LinkType Value 207 LinkType Name LINKTYPE_LAPB_WITH_DIR Description X.25 LAPB, with a direction header Reference [LINKTYPE_LAPB_WITH_DIR] LinkType Value 208 LinkType Name WillBarker-Proprietary Description Proprietary Link-Layer type LinkType Value 209 LinkType Name LINKTYPE_I2C_LINUX Description Linux I2C packets Reference [LINKTYPE_I2C_LINUX] Harris & Richardson Expires 3 September 2026 [Page 15] Internet-Draft pcaplinktype March 2026 LinkType Value 210 LinkType Name LINKTYPE_FLEXRAY Description FlexRay frames or symbols, with a pseudo-header Reference [LINKTYPE_FLEXRAY] LinkType Value 211 LinkType Name LINKTYPE_MOST Description Media Oriented Systems Transport (MOST) bus LinkType Value 212 LinkType Name LINKTYPE_LIN Description Local Interconnect Network (LIN) automotive bus, with a metadata header Reference [LINKTYPE_LIN] LinkType Value 213 LinkType Name LINKTYPE_X2E_SERIAL Description X2E serial line captures LinkType Value 214 LinkType Name LINKTYPE_X2E_XORAYA Description X2E Xoraya data loggers LinkType Value 215 LinkType Name LINKTYPE_IEEE802_15_4_NONASK_PHY Description IEEE 802.15.4 with PHY header Reference [LINKTYPE_IEEE802_15_4_NONASK_PHY] LinkType Value 216 LinkType Name LINKTYPE_LINUX_EVDEV Description Linux evdev messages LinkType Value 217 LinkType Name LINKTYPE_GSMTAP_UM Description GSM Um interface, with gsmtap header LinkType Value 218 LinkType Name LINKTYPE_GSMTAP_ABIS Description GSM Abis interface, with gsmtap header LinkType Value 219 LinkType Name LINKTYPE_MPLS Description MPLS packets with MPLS label as the header LinkType Value 220 LinkType Name LINKTYPE_USB_LINUX_MMAPPED Description USB packets, beginning with an extended Linux USB header Reference [LINKTYPE_USB_LINUX_MMAPPED] Harris & Richardson Expires 3 September 2026 [Page 16] Internet-Draft pcaplinktype March 2026 LinkType Value 221 LinkType Name LINKTYPE_DECT Description DECT packets, with a pseudo-header LinkType Value 222 LinkType Name LINKTYPE_AOS Description OS Space Data Link Protocol LinkType Value 223 LinkType Name LINKTYPE_WIHART Description Wireless HART (Highway Addressable Remote Transducer) LinkType Value 224 LinkType Name LINKTYPE_FC_2 Description Fibre Channel FC-2 frames Reference [LINKTYPE_FC_2] LinkType Value 225 LinkType Name LINKTYPE_FC_2_WITH_FRAME_DELIMS Description Fibre Channel FC-2 frames with SOF and EOF Reference [LINKTYPE_FC_2_WITH_FRAME_DELIMS] LinkType Value 226 LinkType Name LINKTYPE_IPNET Description Solaris ipnet Reference [LINKTYPE_IPNET] LinkType Value 227 LinkType Name LINKTYPE_CAN_SOCKETCAN Description Controller Area Network (CAN) frames, with a metadata header Reference [LINKTYPE_CAN_SOCKETCAN] LinkType Value 228 LinkType Name LINKTYPE_IPV4 Description IPv4 without link-layer headers Reference [LINKTYPE_IPV4] [RFC791] LinkType Value 229 LinkType Name LINKTYPE_IPV6 Description IPv6 without link-layer headers Reference [LINKTYPE_IPV6] [RFC8200] LinkType Value 230 LinkType Name LINKTYPE_IEEE802_15_4_NOFCS Description IEEE 802.15.4 without FCS Reference [LINKTYPE_IEEE802_15_4_NOFCS] Harris & Richardson Expires 3 September 2026 [Page 17] Internet-Draft pcaplinktype March 2026 LinkType Value 231 LinkType Name LINKTYPE_DBUS Description D-Bus messages Reference [LINKTYPE_DBUS] LinkType Value 232 LinkType Name LINKTYPE_JUNIPER_VS Description Juniper Networks LinkType Value 233 LinkType Name LINKTYPE_JUNIPER_SRX_E2E Description Juniper Networks LinkType Value 234 LinkType Name LINKTYPE_JUNIPER_FIBRECHANNEL Description Juniper Networks LinkType Value 235 LinkType Name LINKTYPE_DVB_CI Description DVB-CI messages, with a pseudo-header Reference [DVB-CI-PCAP] LinkType Value 236 LinkType Name LINKTYPE_MUX27010 Description Variant of 3GPP TS 27.010 multiplexing protocol Reference [LINKTYPE_MUX27010] LinkType Value 237 LinkType Name LINKTYPE_STANAG_5066_D_PDU Description STANAG 5066 D_PDUs Reference [LINKTYPE_STANAG_5066_D_PDU] LinkType Value 238 LinkType Name LINKTYPE_JUNIPER_ATM_CEMIC Description Juniper Networks LinkType Value 239 LinkType Name LINKTYPE_NFLOG Description Linux netlink NETLINK NFLOG socket log messages Reference [LINKTYPE_NFLOG] LinkType Value 240 LinkType Name LINKTYPE_NETANALYZER Description Ethernet frames with netANALYZER pseudo-header Reference [LINKTYPE_NETANALYZER] LinkType Value 241 LinkType Name LINKTYPE_NETANALYZER_TRANSPARENT Harris & Richardson Expires 3 September 2026 [Page 18] Internet-Draft pcaplinktype March 2026 Description Ethernet frames with netANALYZER pseudo-header, preamble, and SFD Reference [LINKTYPE_NETANALYZER_TRANSPARENT] LinkType Value 242 LinkType Name LINKTYPE_IPOIB Description IP-over-InfiniBand Reference [LINKTYPE_IPOIB] LinkType Value 243 LinkType Name LINKTYPE_MPEG_2_TS Description MPEG-2 Transport Stream transport packets Reference [LINKTYPE_MPEG_2_TS] LinkType Value 244 LinkType Name LINKTYPE_NG40 Description Frames from ng4T GmbH's ng40 protocol tester Reference [LINKTYPE_NG40] LinkType Value 245 LinkType Name LINKTYPE_NFC_LLCP Description NFC Logical Link Control Protocol frames, with a pseudo- header Reference [LINKTYPE_NFC_LLCP] LinkType Value 246 LinkType Name LINKTYPE_PFSYNC Description pfsync output LinkType Value 247 LinkType Name LINKTYPE_INFINIBAND Description InfiniBand data packets Reference [LINKTYPE_INFINIBAND] LinkType Value 248 LinkType Name LINKTYPE_SCTP Description SCTP packets, with no lower-level protocols such as IPv4 or IPv6 Reference [RFC9260] LinkType Value 249 LinkType Name LINKTYPE_USBPCAP Description USB packets, beginning with a USBPcap header Reference [USBPcap] LinkType Value 250 LinkType Name LINKTYPE_RTAC_SERIAL Description Serial-line packet from the Schweitzer Engineering Harris & Richardson Expires 3 September 2026 [Page 19] Internet-Draft pcaplinktype March 2026 Laboratories RTAC product Reference [LINKTYPE_RTAC_SERIAL] LinkType Value 251 LinkType Name LINKTYPE_BLUETOOTH_LE_LL Description Bluetooth Low Energy link-layer packets Reference [LINKTYPE_BLUETOOTH_LE_LL] LinkType Value 252 LinkType Name LINKTYPE_WIRESHARK_UPPER_PDU Description Wireshark LinkType Value 253 LinkType Name LINKTYPE_NETLINK Description Linux Netlink capture encapsulation Reference [LINKTYPE_NETLINK] LinkType Value 254 LinkType Name LINKTYPE_BLUETOOTH_LINUX_MONITOR Description Bluetooth Linux Monitor Reference [LINKTYPE_BLUETOOTH_LINUX_MONITOR] LinkType Value 255 LinkType Name LINKTYPE_BLUETOOTH_BREDR_BB Description Bluetooth Basic Rate and Enhanced Data Rate baseband packets Reference [LINKTYPE_BLUETOOTH_BREDR_BB] LinkType Value 256 LinkType Name LINKTYPE_BLUETOOTH_LE_LL_WITH_PHDR Description Bluetooth Low Energy link-layer packets Reference [LINKTYPE_BLUETOOTH_LE_LL_WITH_PHDR] LinkType Value 257 LinkType Name LINKTYPE_PROFIBUS_DL Description PROFIBUS data link layer packets Reference [LINKTYPE_PROFIBUS_DL] LinkType Value 258 LinkType Name LINKTYPE_PKTAP Description Apple PKTAP capture encapsulation Reference [LINKTYPE_PKTAP] LinkType Value 259 LinkType Name LINKTYPE_EPON Description Ethernet-over-passive-optical-network packets, including preamble octets Reference [LINKTYPE_EPON] Harris & Richardson Expires 3 September 2026 [Page 20] Internet-Draft pcaplinktype March 2026 LinkType Value 260 LinkType Name LINKTYPE_IPMI_HPM_2 Description IPMI HPM.2 trace packets Reference [LINKTYPE_IPMI_HPM_2] LinkType Value 261 LinkType Name LINKTYPE_ZWAVE_R1_R2 Description Z-Wave RF profile R1 and R2 packets Reference [LINKTYPE_ZWAVE_R1_R2] LinkType Value 262 LinkType Name LINKTYPE_ZWAVE_R3 Description Z-Wave RF profile R3 packets Reference [LINKTYPE_ZWAVE_R3] LinkType Value 263 LinkType Name LINKTYPE_WATTSTOPPER_DLM Description WattStopper Digital Lighting Management (DLM) and Legrand Nitoo Open protocol packets Reference [LINKTYPE_WATTSTOPPER_DLM] LinkType Value 264 LinkType Name LINKTYPE_ISO_14443 Description ISO 14443 contactless smartcard messages Reference [ISO-14443-PCAP] LinkType Value 265 LinkType Name LINKTYPE_RDS Description IEC 62106 Radio data system (RDS) groups Reference [LINKTYPE_RDS] LinkType Value 266 LinkType Name LINKTYPE_USB_DARWIN Description USB packets captured on a Darwin-based operating system (macOS, etc.) Reference [LINKTYPE_USB_DARWIN] LinkType Value 267 LinkType Name LINKTYPE_OPENFLOW Description OpenBSD DLT_OPENFLOW LinkType Value 268 LinkType Name LINKTYPE_SDLC Description SNA SDLC packets Reference [LINKTYPE_SDLC] LinkType Value 269 LinkType Name LINKTYPE_TI_LLN_SNIFFER Harris & Richardson Expires 3 September 2026 [Page 21] Internet-Draft pcaplinktype March 2026 Description Texas Instruments protocol sniffer LinkType Value 270 LinkType Name LINKTYPE_LORATAP Description LoRaWan packets with a LoRaTap pseudo-header Reference [LINKTYPE_LORATAP] LinkType Value 271 LinkType Name LINKTYPE_VSOCK Description Protocol for communication between host and guest machines in VMware and KVM hypervisors Reference [LINKTYPE_VSOCK] LinkType Value 272 LinkType Name LINKTYPE_NORDIC_BLE Description Messages to and from a Nordic Semiconductor nRF Sniffer for Bluetooth LE packets Reference [LINKTYPE_NORDIC_BLE] LinkType Value 273 LinkType Name LINKTYPE_DOCSIS31_XRA31 Description DOCSIS packets and bursts, preceded by a pseudo-header Reference [DOCSIS-XRA] [DOCSIS-4.0-MULP] LinkType Value 274 LinkType Name LINKTYPE_ETHERNET_MPACKET Description IEEE 802.3 mPackets Reference [LINKTYPE_ETHERNET_MPACKET] LinkType Value 275 LinkType Name LINKTYPE_DISPLAYPORT_AUX Description DisplayPort AUX channel monitoring messages Reference [LINKTYPE_DISPLAYPORT_AUX] LinkType Value 276 LinkType Name LINKTYPE_LINUX_SLL2 Description Linux cooked capture encapsulation v2 Reference [LINKTYPE_LINUX_SLL2] LinkType Value 277 LinkType Name LINKTYPE_SERCOS_MONITOR Description Sercos Monitor LinkType Value 278 LinkType Name LINKTYPE_OPENVIZSLA Description OpenVizsla FPGA-based USB sniffer Reference [OpenVizsla] Harris & Richardson Expires 3 September 2026 [Page 22] Internet-Draft pcaplinktype March 2026 LinkType Value 279 LinkType Name LINKTYPE_EBHSCR Description Elektrobit High Speed Capture and Replay (EBHSCR) format Reference [EBHSCR] LinkType Value 280 LinkType Name LINKTYPE_VPP_DISPATCH Description fd.io VPP graph dispatcher trace records Reference [FD.io-VPP] LinkType Value 281 LinkType Name LINKTYPE_DSA_TAG_BRCM Description Ethernet frames, with a Broadcom switch tag inserted Reference [LINKTYPE_DSA_TAG_BRCM] LinkType Value 282 LinkType Name LINKTYPE_DSA_TAG_BRCM_PREPEND Description Ethernet frames, with a Broadcom switch tag prepended Reference [LINKTYPE_DSA_TAG_BRCM_PREPEND] LinkType Value 283 LinkType Name LINKTYPE_IEEE802_15_4_TAP Description IEEE 802.15.4 with a tap header preceding it Reference [Exegin-802.15.4-TAP] LinkType Value 284 LinkType Name LINKTYPE_DSA_TAG_DSA Description Ethernet frames, with a Marvell DSA switch tag inserted Reference [LINKTYPE_DSA_TAG_DSA] LinkType Value 285 LinkType Name LINKTYPE_DSA_TAG_EDSA Description Ethernet frames, with a Marvell EDSA switch tag inserted Reference [LINKTYPE_DSA_TAG_EDSA] LinkType Value 286 LinkType Name LINKTYPE_ELEE Description ELEE lawful intercept protocol LinkType Value 287 LinkType Name LINKTYPE_Z_WAVE_SERIAL Description Serial frames transmitted between a host and a Z-Wave chip over an RS-232 or USB serial connection Reference [Z-WAVE-SERIAL] section 5 LinkType Value 288 LinkType Name LINKTYPE_USB_2_0 Description USB 2.0, 1.1, or 1.0 packets Harris & Richardson Expires 3 September 2026 [Page 23] Internet-Draft pcaplinktype March 2026 Reference [LINKTYPE_USB_2_0] LinkType Value 289 LinkType Name LINKTYPE_ATSC_ALP Description ATSC Link-Layer Protocol frames Reference [LINKTYPE_ATSC_ALP] LinkType Value 290 LinkType Name LINKTYPE_ETW Description Event Tracing for Windows messages Reference [LINKTYPE_ETW] LinkType Value 291 LinkType Name LINKTYPE_NETANALYZER_NG Description Hilscher Gesellschaft fuer Systemautomation mbH netANALYZER NG hardware and software LinkType Value 292 LinkType Name LINKTYPE_ZBOSS_NCP Description ZBOSS NCP Serial Protocol, with a pseudo-header Reference [LINKTYPE_ZBOSS_NCP] LinkType Value 293 LinkType Name LINKTYPE_USB_2_0_LOW_SPEED Description Low-Speed USB 2.0, 1.1, or 1.0 packets Reference [LINKTYPE_USB_2_0_LOW_SPEED] LinkType Value 294 LinkType Name LINKTYPE_USB_2_0_FULL_SPEED Description Full-Speed USB 2.0, 1.1, or 1.0 packets Reference [LINKTYPE_USB_2_0_FULL_SPEED] LinkType Value 295 LinkType Name LINKTYPE_USB_2_0_HIGH_SPEED Description High-Speed USB 2.0 packets Reference [LINKTYPE_USB_2_0_HIGH_SPEED] LinkType Value 296 LinkType Name LINKTYPE_AUERSWALD_LOG Description Auerswald Logger Protocol Reference [Auerswald-Logger] LinkType Value 297 LinkType Name LINKTYPE_ZWAVE_TAP Description Z-Wave packets, with a metadata header Reference [LINKTYPE_ZWAVE_TAP] LinkType Value 298 Harris & Richardson Expires 3 September 2026 [Page 24] Internet-Draft pcaplinktype March 2026 LinkType Name LINKTYPE_SILABS_DEBUG_CHANNEL Description Silicon Labs debug channel protocol Reference [Silabs-Debug-Channel] LinkType Value 299 LinkType Name LINKTYPE_FIRA_UCI Description Ultra-wideband (UWB) controller interface protocol (UCI) Reference [LINKTYPE_FIRA_UCI] LinkType Value 300 LinkType Name LINKTYPE_MDB Description MDB (Multi-Drop Bus) protocol Reference [MDB-PCAP] LinkType Value 301 LinkType Name LINKTYPE_DECT_NR Description DECT-2020 New Radio (NR) MAC layer Reference [LINKTYPE_DECT_NR] 2.2.2. Guidance for Designated Experts When processing a request for an allocation, the Designated Experts will encourage the requester to provide a specification at a stable URL. There is no requirement for a specification, but often review of the specification allows the Designated Expert to determine if the allocation actually is a duplicate of another specification. When the contents of the link type can contain an IPv4 or IPv6 header, then the octets between the beginning of the link type and the IP header needs to be clearly specified. Registrations for specifications that are not publicly available are acceptable. This includes specifications obtained via liaison agreements (such as to ITU-T, drafts, IEEE, etc.), those that may eventually be made public, or those for which no public document will be available. The minimal requirement is to provide a contact for that link type. For other documents, the Designated Expert will need use their judgement, or consult the OPSAWG or an Area Director. Harris & Richardson Expires 3 September 2026 [Page 25] Internet-Draft pcaplinktype March 2026 3. Security Considerations This document describes the IANA registration rules for the LinkType encapsulations. PCAP-related packet file formats use this value to determine what kind of headers precede network packet captures. Many of these formats can contain IPv4 and IPv6 packets. A system reading PCAP-related format captures can be subject to arbitrary inputs that may be controlled by malicious entities, so utmost caution is required. Many LinkType formats include a "snapshot" length, which may be smaller than the actual packet. It is therefore very likely that trailing parts of a packet capture may be omitted, yet internal length fields in the packets will claim the packet is bigger than the capture. This leads to trivial buffer overreads, and systems interpreting the packets need to carefully scrutinize all attempts to read data from a capture. 4. Contributors PCAP has been developed over three and half decades by a variety of developers, including: Bill Fenner, Denis Ovsienko, Francois-Xavier Le Bail, Fulvio Risso, Gerald Combs, Gianluca Varenni, Gisle Vanem, Hannes Gredler, Joerg Mayer, Michal Sekletar, Stephen Donnelly, Torsten Landschoff, and Jun-ichiro itojun Hagino. PCAP was originally created at LBL by Steve McCanne, Craig Leres, and Van Jacobson. 5. Acknowledgments The authors wish to thank: Michael Tuexen, Mohamed Boucadair, Carsten Bormann, Henk Birkholtz, and Robert Wilton their invaluable comments and encouragement. 6. References 6.1. Normative References [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 8126, DOI 10.17487/RFC8126, June 2017, . 6.2. Informative References Harris & Richardson Expires 3 September 2026 [Page 26] Internet-Draft pcaplinktype March 2026 [LINKTYPES] "LINK-LAYER HEADER TYPES", . [LIBPCAP] "PCAP Library", . [Wireshark] "Homepage of Wireshark", . [_3GPP-TS-04.64] "Digital cellular telecommunications system (Phase 2+); General Packet Radio Service (GPRS); Mobile Station - Serving GPRS Support Node (MS-SGSN) Logical Link Control (LLC) layer specification", 3GPP TS 04.64. [AIM-628] Moon, D. A., "Chaosnet", MIT A.I. Memo No. 628, June 1981, . [Auerswald-Logger] "Packet structure", n.d., . [AVS] Peachy, S., "AVS Capture Frame Format Version 2", . [DOCSIS-4.0-MULP] "DOCSIS 4.0 MAC and Upper Layer Protocols Interface Specification", . [DOCSIS-XRA] "Excentis XRA Header Definition", . [DVB-CI-PCAP] Kaiser, M., "PCAP format for DVB-CI", January 2021, . [EBHSCR] "Documentation EBHSCR", . [Exegin-802.15.4-TAP] "IEEE 802.15.4 TAP Link Type Specification", . Harris & Richardson Expires 3 September 2026 [Page 27] Internet-Draft pcaplinktype March 2026 [FD.io-VPP] "VNET (VPP Network Stack)", . [G.7041] "Generic Framing Procedure", ITU-T Recommendation G.7041/ Y.1303, . [ISO-14443-PCAP] Kaiser, M., "PCAP format for ISO14443", January 2021, . [LINKTYPE_APPLE_IP_OVER_IEEE1394] "LINKTYPE_APPLE_IP_OVER_IEEE1394", . [LINKTYPE_ATM_RFC1483] "LINKTYPE_ATM_RFC1483", . [LINKTYPE_ATSC_ALP] "LINKTYPE_ATSC_ALP", . [LINKTYPE_AX25] "LINKTYPE_AX25", . [LINKTYPE_AX25_KISS] "LINKTYPE_AX25_KISS", . [LINKTYPE_BACNET_MS_TP] "LINKTYPE_BACNET_MS_TP", . [LINKTYPE_BLUETOOTH_BREDR_BB] "LINKTYPE_BLUETOOTH_BREDR_BB", . [LINKTYPE_BLUETOOTH_HCI_H4] "LINKTYPE_BLUETOOTH_HCI_H4", . Harris & Richardson Expires 3 September 2026 [Page 28] Internet-Draft pcaplinktype March 2026 [LINKTYPE_BLUETOOTH_HCI_H4_WITH_PHDR] "LINKTYPE_BLUETOOTH_HCI_H4_WITH_PHDR", . [LINKTYPE_BLUETOOTH_LE_LL] "LINKTYPE_BLUETOOTH_LE_LL", . [LINKTYPE_BLUETOOTH_LE_LL_WITH_PHDR] "LINKTYPE_BLUETOOTH_LE_LL_WITH_PHDR", . [LINKTYPE_BLUETOOTH_LINUX_MONITOR] "LINKTYPE_BLUETOOTH_LINUX_MONITOR", . [LINKTYPE_C_HDLC] "LINKTYPE_C_HDLC", . [LINKTYPE_C_HDLC_WITH_DIR] "LINKTYPE_C_HDLC_WITH_DIR", . [LINKTYPE_CAN_SOCKETCAN] "LINKTYPE_CAN_SOCKETCAN", . [LINKTYPE_DBUS] "LINKTYPE_DBUS", . [LINKTYPE_DECT_NR] "LINKTYPE_DECT_NR", . [LINKTYPE_DISPLAYPORT_AUX] "LINKTYPE_DISPLAYPORT_AUX", . Harris & Richardson Expires 3 September 2026 [Page 29] Internet-Draft pcaplinktype March 2026 [LINKTYPE_DSA_TAG_BRCM] "LINKTYPE_DSA_TAG_BRCM", . [LINKTYPE_DSA_TAG_BRCM_PREPEND] "LINKTYPE_DSA_TAG_BRCM_PREPEND", . [LINKTYPE_DSA_TAG_DSA] "LINKTYPE_DSA_TAG_DSA", . [LINKTYPE_DSA_TAG_EDSA] "LINKTYPE_DSA_TAG_EDSA", . [LINKTYPE_ETHERNET] "IEEE 802.3 Ethernet", . [LINKTYPE_EPON] "LINKTYPE_EPON", . [LINKTYPE_ERF] "LINKTYPE_ERF", . [LINKTYPE_ETW] "LINKTYPE_ETW", . [LINKTYPE_ETHERNET_MPACKET] "LINKTYPE_ETHERNET_MPACKET", . [LINKTYPE_FC_2] "LINKTYPE_FC_2", . Harris & Richardson Expires 3 September 2026 [Page 30] Internet-Draft pcaplinktype March 2026 [LINKTYPE_FC_2_WITH_FRAME_DELIMS] "LINKTYPE_FC_2_WITH_FRAME_DELIMS", . [LINKTYPE_FIRA_UCI] "LINKTYPE_FIRA_UCI", . [LINKTYPE_FLEXRAY] "LINKTYPE_FLEXRAY", . [LINKTYPE_FRELAY] "LINKTYPE_FRELAY", . [LINKTYPE_FRELAY_WITH_DIR] "LINKTYPE_FRELAY_WITH_DIR", . [LINKTYPE_I2C_LINUX] "LINKTYPE_I2C_LINUX", . [LINKTYPE_IEEE802_11_PRISM] "LINKTYPE_IEEE802_11_PRISM", . [LINKTYPE_IEEE802_15_4_NOFCS] "LINKTYPE_IEEE802_15_4_NOFCS", . [LINKTYPE_IEEE802_15_4_NONASK_PHY] "LINKTYPE_IEEE802_15_4_NONASK_PHY", . [LINKTYPE_IEEE802_15_4_WITHFCS] "LINKTYPE_IEEE802_15_4_WITHFCS", . Harris & Richardson Expires 3 September 2026 [Page 31] Internet-Draft pcaplinktype March 2026 [LINKTYPE_IPV4] "LINKTYPE_IPV4", . [LINKTYPE_IPV6] "LINKTYPE_IPV6", . [LINKTYPE_IPOIB] "LINKTYPE_IPOIB", . [LINKTYPE_IP_OVER_FC] "LINKTYPE_IP_OVER_FC", . [LINKTYPE_INFINIBAND] "LINKTYPE_INFINIBAND", . [LINKTYPE_IPMI_HPM_2] "LINKTYPE_IPMI_HPM_2", . [LINKTYPE_IPNET] "LINKTYPE_IPNET", . [LINKTYPE_LAPB_WITH_DIR] "LINKTYPE_LAPB_WITH_DIR", . [LINKTYPE_LAPD] "LINKTYPE_LAPD", . [LINKTYPE_LIN] "LINKTYPE_LIN", . [LINKTYPE_LINUX_IRDA] "LINKTYPE_LINUX_IRDA", . [LINKTYPE_LINUX_LAPD] "LINKTYPE_LINUX_LAPD", . Harris & Richardson Expires 3 September 2026 [Page 32] Internet-Draft pcaplinktype March 2026 [LINKTYPE_LINUX_SLL] "LINKTYPE_LINUX_SLL", . [LINKTYPE_LINUX_SLL2] "LINKTYPE_LINUX_SLL2", . [LINKTYPE_LOOP] "LINKTYPE_LOOP", . [LINKTYPE_LORATAP] "LINKTYPE_LORATAP", . [LINKTYPE_LTALK] "LINKTYPE_LTALK", . [LINKTYPE_MFR] "LINKTYPE_MFR", . [LINKTYPE_MPEG_2_TS] "LINKTYPE_MPEG_2_TS", . [LINKTYPE_MTP2] "LINKTYPE_MTP2", . [LINKTYPE_MTP2_WITH_PHDR] "LINKTYPE_MTP2_WITH_PHDR", . [LINKTYPE_MTP3] "LINKTYPE_MTP3", . [LINKTYPE_SCCP] "LINKTYPE_SCCP", . [LINKTYPE_MUX27010] "LINKTYPE_MUX27010", . Harris & Richardson Expires 3 September 2026 [Page 33] Internet-Draft pcaplinktype March 2026 [LINKTYPE_NETANALYZER] "LINKTYPE_NETANALYZER", . [LINKTYPE_NETANALYZER_TRANSPARENT] "LINKTYPE_NETANALYZER_TRANSPARENT", . [LINKTYPE_NETLINK] "LINKTYPE_NETLINK", . [LINKTYPE_NFC_LLCP] "LINKTYPE_NFC_LLCP", . [LINKTYPE_NFLOG] "LINKTYPE_NFLOG", . [LINKTYPE_NG40] "LINKTYPE_NG40", . [LINKTYPE_NORDIC_BLE] "LINKTYPE_NORDIC_BLE", . [LINKTYPE_NULL] "LINKTYPE_NULL", . [LINKTYPE_PKTAP] "LINKTYPE_PKTAP", . [LINKTYPE_PPI] "LINKTYPE_PPI", . [LINKTYPE_PPP] "LINKTYPE_PPP", . Harris & Richardson Expires 3 September 2026 [Page 34] Internet-Draft pcaplinktype March 2026 [LINKTYPE_PPP_ETHER] "LINKTYPE_PPP_ETHER", . [LINKTYPE_PPP_HDLC] "LINKTYPE_PPP_HDLC", . [LINKTYPE_PPP_PPPD] "LINKTYPE_PPP_PPPD", . [LINKTYPE_PPP_WITH_DIR] "LINKTYPE_PPP_WITH_DIR", . [LINKTYPE_PROFIBUS_DL] "LINKTYPE_PROFIBUS_DL", . [LINKTYPE_RAW] "LINKTYPE_RAW", . [LINKTYPE_RDS] "LINKTYPE_RDS", . [LINKTYPE_RTAC_SERIAL] "LINKTYPE_RTAC_SERIAL", . [LINKTYPE_SDLC] "LINKTYPE_SDLC", . [LINKTYPE_SITA] "LINKTYPE_SITA", . [LINKTYPE_SLIP] "LINKTYPE_SLIP", . Harris & Richardson Expires 3 September 2026 [Page 35] Internet-Draft pcaplinktype March 2026 [LINKTYPE_STANAG_5066_D_PDU] "LINKTYPE_STANAG_5066_D_PDU", . [LINKTYPE_SUNATM] "LINKTYPE_SUNATM", . [LINKTYPE_USB_2_0] "LINKTYPE_USB_2_0", . [LINKTYPE_USB_2_0_FULL_SPEED] "LINKTYPE_USB_2_0_FULL_SPEED", . [LINKTYPE_USB_2_0_HIGH_SPEED] "LINKTYPE_USB_2_0_HIGH_SPEED", . [LINKTYPE_USB_2_0_LOW_SPEED] "LINKTYPE_USB_2_0_LOW_SPEED", . [LINKTYPE_USB_DARWIN] "LINKTYPE_USB_DARWIN", . [LINKTYPE_USB_LINUX] "LINKTYPE_USB_LINUX", . [LINKTYPE_USB_LINUX_MMAPPED] "LINKTYPE_USB_LINUX_MMAPPED", . [LINKTYPE_VSOCK] "LINKTYPE_VSOCK", . Harris & Richardson Expires 3 September 2026 [Page 36] Internet-Draft pcaplinktype March 2026 [LINKTYPE_WATTSTOPPER_DLM] "LINKTYPE_WATTSTOPPER_DLM", . [LINKTYPE_ZBOSS_NCP] "LINKTYPE_ZBOSS_NCP", . [LINKTYPE_ZWAVE_R1_R2] "LINKTYPE_ZWAVE_R1_R2", . [LINKTYPE_ZWAVE_R3] "LINKTYPE_ZWAVE_R3", . [LINKTYPE_ZWAVE_TAP] "LINKTYPE_ZWAVE_TAP", . [MDB-PCAP] Kaiser, M., "PCAP format for MDB", August 2023, . [OpenVizsla] "OpenVizsla protocol description", August 2018, . [PracConsEthDesign] Crane, R. C. and E. A. Taft, "Practical Considerations in Ethernet Local Network Design", February 1980, . [Radiotap] radiotap.org, "Radiotap Web site", . [Silabs-Debug-Channel] "Silabs Debug Channel Format", n.d., . [USBPcap] "USBPcap Capture format specification", . Harris & Richardson Expires 3 September 2026 [Page 37] Internet-Draft pcaplinktype March 2026 [Z-WAVE-SERIAL] "Z-Wave Serial API Host Application Programming Guide", . [I-D.ietf-opsawg-pcap] Harris, G. and M. Richardson, "PCAP Capture File Format", Work in Progress, Internet-Draft, draft-ietf-opsawg-pcap- 06, 3 September 2025, . [I-D.ietf-opsawg-pcapng] Tüxen, M., Risso, F., Bongertz, J., Combs, G., Harris, G., Chaudron, E., and M. Richardson, "PCAP Now Generic (pcapng) Capture File Format", Work in Progress, Internet- Draft, draft-ietf-opsawg-pcapng-04, 30 August 2025, . [RFC791] Postel, J., "Internet Protocol", STD 5, RFC 791, DOI 10.17487/RFC0791, September 1981, . [RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6 (IPv6) Specification", STD 86, RFC 8200, DOI 10.17487/RFC8200, July 2017, . [RFC9260] Stewart, R., Tüxen, M., and K. Nielsen, "Stream Control Transmission Protocol", RFC 9260, DOI 10.17487/RFC9260, June 2022, . Authors' Addresses Guy Harris (editor) Email: gharris@sonic.net Michael C. Richardson Sandelman Software Works Inc Email: mcr+ietf@sandelman.ca URI: http://www.sandelman.ca/ Harris & Richardson Expires 3 September 2026 [Page 38]