-LINK LAYER-[INTERNET PROTOCOL SUITE]

-as of [1 OCTOBER 2024]-

*in ‘computer networking’, the ‘link layer’ is the lowest layer in the ‘internet protocol suite’*

*it is the ‘networking architecture’ of the ‘internet’*

This category contains link protocols used in the Data Link Layer (Layer 2) of the OSI model and the Link Layer of the Internet Protocol Suite.

Note that in some text books, the term Link Layer also includes Physical Layer protocols, but those are not listed here, but in Category:Physical layer protocols.

Subcategories
This category has the following 10 subcategories, out of 10 total.

A
► Address Resolution Protocol‎ (2 P)

B
► Bonding protocols‎ (6 P)

E
► Ethernet‎ (4 C, 138 P)

F
► Frame Relay‎ (8 P)

I
► IEEE 802‎ (6 C, 59 P)

► IEEE 802.11‎ (80 P)

L
► Link access protocols‎ (6 P)

► Logical link control‎ (3 C, 23 P)

M
► Media access control‎ (1 C, 23 P)

W
► Wi-Fi‎ (4 C, 65 P)

Pages in category “Link protocols”
The following 78 pages are in this category, out of 78 total. This list may not reflect recent changes (learn more).

A
Acknowledgement (data networks)
Advanced Data Communication Control Procedures
Asynchronous Transfer Mode
Aurora (protocol)
AX.25
B
Binary Synchronous Communications
Bonjour Sleep Proxy
C
Cell Loss Priority
Cisco HDLC
D
Data link connection identifier
Data link layer
Discovery and Configuration Protocol
Distributed-queue dual-bus
DOCSIS
Dynamic synchronous transfer mode
F
Fiber Distributed Data Interface
Frame (networking)
Frame check sequence
Frame Relay
FX.25 Forward Error Correction
G
G.hn
General Packet Radio Service
Generic Stream Encapsulation
H
High-Level Data Link Control
I
IBM 1009
IEEE 802.1AE
IEEE 802.1aq
IEEE 802.2
Improved Layer 2 Protocol
Intelligent Resilient Framework
InterSwitch Trunk
IP over Avian Carriers
IPoE
L
LAPB
Link access procedure
Link Access Procedure for Frame Relay
Link aggregation
Link Control Protocol
Link layer
Link Layer Discovery Protocol
Link Layer Topology Discovery
LocalTalk
M
Multi-chassis link aggregation group
Medium access control
Metro Ring Protocol
Multi-link trunking
Multilink Procedure
Multiple Spanning Tree Protocol
Multiprotocol Encapsulation
N
Neighbor Discovery Protocol
Network interface layer security
O
Open Shortest Path First
P
Parallel Line Internet Protocol
PAROLI
Point-to-Point Protocol
Port Aggregation Protocol
R
Radio Link Protocol
Reverse Address Resolution Protocol
S
Secure Neighbor Discovery
Semaphore Flag Signaling System
Serial Line Internet Protocol
Shortest Path Bridging
Simple Loop Prevention Protocol
Software Communications Architecture
Spanning Tree Protocol
Subnetwork Access Protocol
Synchronous Data Link Control
Synchronous transmit-receive
T
Token bus network
Token Ring
TRILL (computing)
U
Unidirectional Lightweight Encapsulation
Unidirectional Link Detection
V
V5 interface
VB5 interface
Virtual Link Aggregation Control Protocol
Virtual Link Trunking
Z
Zero code suppression
Retrieved from “https://en.wikipedia.org/w/index.php?title=Category:Link_protocols&oldid=718004075”

Categories:

Internet protocols
Protocols by OSI layer

en.wikipedia.org /wiki/Category:Link_protocols
Category:Link protocols – Wikipedia
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The link layer is the group of methods and communications protocols confined to the link that a host is physically connected to.

The link is the physical and logical network component used to interconnect hosts or nodes in the network and a link protocol is a suite of methods and standards that operate only between adjacent network nodes of a network segment.

Despite the different semantics of layering between the Internet protocol suite and OSI model, the link layer is sometimes described as a combination of the OSI’s data link layer (layer 2) and physical layer (layer 1).

The link layer is described in RFC 1122 and RFC 1123. RFC 1122 considers local area network protocols such as Ethernet and other IEEE 802 networks (e.g. Wi-Fi), and framing protocols such as Point-to-Point Protocol (PPP) to belong to the link layer.

Definition in standards and textbooks[edit]
Local area networking standards such as Ethernet and IEEE 802.3 specifications use terminology from the seven-layer OSI model rather than the TCP/IP model. The TCP/IP model, in general, does not consider physical specifications, rather it assumes a working network infrastructure that can deliver media-level frames on the link. Therefore, RFC 1122 and RFC 1123, the definition of the TCP/IP model, do not discuss hardware issues and physical data transmission and set no standards for those aspects. Some textbook authors have supported the interpretation that physical data transmission aspects are part of the link layer.[1][2] Others assumed that physical data transmission standards are not considered communication protocols, and are not part of the TCP/IP model.[3][4] These authors assume a hardware layer or physical layer below the link layer, and several of them adopt the OSI term data link layer instead of link layer in a modified description of layering. In the predecessor to the TCP/IP model, the ARPAnet Reference Model (RFC 908, 1982), aspects of the link layer are referred to by several poorly defined terms, such as network-access layer, network-access protocol, as well as network layer, while the next higher layer is called internetwork layer. In some modern textbooks, network-interface layer, host-to-network layer and network-access layer occur as synonyms either to the link layer or the data link layer, often including the physical layer.

Link layer protocols[edit]
The link layer in the TCP/IP model is a descriptive realm of networking protocols that operate only on the local network segment (link) that a host is connected to. Such protocol packets are not routed to other networks. The link layer includes the protocols that define communication between local (on-link) network nodes which fulfill the purpose of maintaining link states between the local nodes, such as the local network topology, and that usually use protocols that are based on the framing of packets specific to the link types.

The core protocols specified by the Internet Engineering Task Force (IETF) in this layer are the Address Resolution Protocol (ARP), the Reverse Address Resolution Protocol (RARP), and the Neighbor Discovery Protocol (NDP), which is a facility delivering similar functionality as ARP for IPv6. Since the advent of IPv6, Open Shortest Path First (OSPF) is considered to operate on the link level as well, although the IPv4 version of the protocol was considered at the Internet layer.[citation needed]

IS-IS (RFC 1142) is another link-state routing protocol that fits into this layer when considering TCP/IP model, however, it was developed within the OSI reference stack, where it is a Layer 2 protocol. It is not an Internet standard.

Relation to OSI model[edit]
The link layer of the TCP/IP model is often compared directly with the combination of the data link layer and the physical layer in the Open Systems Interconnection (OSI) protocol stack. Although they are congruent to some degree in technical coverage of protocols, they are not identical. The link layer in TCP/IP is still wider in scope and in principle a different concept and terminology of classification. This may be observed when certain protocols, such as the Address Resolution Protocol (ARP), which is confined to the link layer in the TCP/IP model, is often said to fit between OSI’s data link layer and the network layer. In general, direct or strict comparisons should be avoided, because the layering in TCP/IP is not a principal design criterion and in general, is considered to be “harmful” (RFC 3439).

Another term sometimes encountered, network access layer, tries to suggest the closeness of this layer to the physical network. However, this use is misleading and non-standard, since the link layer implies functions that are wider in scope than just network access. Important link layer protocols are used to probe the topology of the local network, discover routers and neighboring hosts, i.e. functions that go well beyond network access

IETF standards

RFC 1122, “Requirements for Internet Hosts — Communication Layers,” IETF, R. Braden (Editor), October 1989

RFC 1123, “Requirements for Internet Hosts — Application and Support,” IETF, R. Braden (Editor), October 1989

RFC 893, “Trailer Encapsulations,” S. Leffler and M. Karels, April 1984

RFC 826, “An Ethernet Address Resolution Protocol,” D. Plummer, November 1982

RFC 894, “A Standard for the Transmission of IP Datagrams over Ethernet Networks,” C. Hornig, April 1984

RFC 1042, “A Standard for the Transmission of IP Datagrams over IEEE 802 Networks,” J. Postel and J. Reynolds, February 1988

RFC 2740, “OSPF for IPv6”, R. Coltun, et al., December 1999