An Ethertype field in each frame is used by the operating system on the receiving station to select the appropriate protocol module ( i. e. the Internet protocol module ).

* A4066 Zorro II Ethernet interface using SMC 91C90QF.

By 1987 Ethernet was clearly winning the standards battle over Token Ring, and in the middle of that year Apple introduced EtherTalk 1. 0 for the newly released Macintosh II computer.

Version 2 was published in November, 1982 and defines what has become known as Ethernet II.

* Ethernet II comprise an Ethernet II frame header ( Destination, Source, EtherType ) followed by IPX data.

IEEE 802. 3 is an exception ; Ethernet originally used Ethernet II framing, with a 2-octet type field containing an EtherType value, and no 802. 2 header, but the original IEEE 802. 3 specification used a framing wherein the 2-octet field following the 6-octet destination and source MAC addresses contained a frame length, with an 802. 2 LLC header following the length field.

* DynamicAccess software products for Ethernet load balancing, response time, and RMON II distributed monitoring.

This field was first defined by the Ethernet II framing networking standard, and later adapted for the IEEE 802. 3 Ethernet networking standard.

However, for Ethernet, the Ethernet II header is still used.

EAPOL operates at the network layer on top of the data link layer, and in Ethernet II framing protocol has an EtherType value of 0x888E.

On Ethernet, this reduces the size of the available payload for protocols such as the Internet Protocol to 1492 bytes, compared to the use of the Ethernet II framing ; therefore, for protocols that have EtherType values, packets are usually transmitted with Ethernet II headers rather than with LLC and SNAP headers.

As per IETF RFC 1042, IP datagrams and ARP datagrams are transmitted over IEEE 802 networks using LLC and SNAP headers, except on Ethernet / IEEE 802. 3, where they are transmitted with Ethernet II headers, as per RFC 894.

Historically, depending on the type of Ethernet framing that was in use on an Ethernet segment, both interpretations were simultaneously valid, leading to ambiguity.

Ethernet v2 framing considered these octets to represent EtherType while the original IEEE 802. 3 framing considered these octets to represent the size of the payload in bytes.

In order to allow packets using Ethernet v2 framing and packets using the IEEE 802. 3 framing to be used on the same Ethernet segment, a unifying standard ( IEEE 802. 3x-1997 ) was introduced that required that EtherType values be greater than or equal to 1536 ( 0x0600 ).

A 1500 byte ( 12000-bit ) full-size Ethernet frame takes only 1. 2 µs to transmit on a 10 Gbit / s network, reducing the need for small cells to reduce jitter due to contention.

Features such as the 48-bit MAC address and Ethernet frame format have influenced other networking protocols.

Ethernet frames are said to be self-identifying, because of the frame type.

Despite the evolution of Ethernet technology, all generations of Ethernet ( excluding early experimental versions ) use the same frame formats ( and hence the same interface for higher layers ), and can be readily interconnected through bridging.

A frame begins with preamble and start frame delimiter, followed by an Ethernet header featuring source and destination MAC addresses.

* Priority Code Point, a three-bit priority field within an Ethernet frame header when using IEEE 802. 1q tagged frames.

For example, in Ethernet the maximum frame size 1526 bytes ( maximum 1500 byte payload + 8 byte preamble + 14 byte header + 4 Byte trailer ).

It is also called 100VG-AnyLAN because it was defined to carry both Ethernet and token ring frame types.

In other words, for ATM ( and eventually other protocols such as Ethernet ), the internal complex structure previously used to transport circuit-oriented connections was removed and replaced with a large and concatenated frame ( such as STS-3c ) into which ATM cells, IP packets, or Ethernet frames are placed.

In packet-oriented data transmission, such as Ethernet, a packet frame usually consists of a header and a payload.

The WAN PHY variant encapsulates Ethernet data using a lightweight SDH / SONET frame, so as to be compatible at a low level with equipment designed to carry SDH / SONET signals, whereas the LAN PHY variant encapsulates Ethernet data using 64B / 66B line coding.

According to Ethernet specifications, collisions should be detected during the first 64 bytes of the frame, so frames that are in error because of a collision will not be forwarded.

Layer 2 switching is highly efficient because there is no modification to the data packet, only to the frame encapsulation of the packet, and only when the data packet is passing through dissimilar media ( such as from Ethernet to FDDI ).

The routers in an Ethernet or frame relay network select a designated router ( DR ) and a backup designated router ( BDR ) which act as a hub to reduce traffic between routers.

A full-size ( 1500 byte ) Ethernet frame takes 94 ms to transmit at 128 kbit / s but only 8 ms at 1. 5 Mbit / s.

This " color " is what is now known in the Ethernet frame as the 802. 1Q header, or the VLAN tag.

ISL uses an external tagging process that does not modify the existing Ethernet frame, while 802. 1Q uses a frame-internal field for tagging, and so does modify the Ethernet frame.

In terms of current popular technologies: Any computer connected to the same Ethernet repeater or switch is a member of the same broadcast domain.

The result is a network based on a nominally shared transmission system ; like Ethernet, but in which " client " nodes cannot communicate with each other, only with the server / provider.

Well-known communications protocols are Ethernet, a hardware and Link Layer standard that is ubiquitous in local area networks, and the Internet Protocol Suite, which defines a set of protocols for internetworking, i. e. for data communication between multiple networks, as well as host-to-host data transfer, and application-specific data transmission formats.

Network connections such as Ethernet are not generally regarded as buses, although the difference is largely conceptual rather than practical.

This distinction is exemplified by a telephone system with a connected modem, where the RJ11 connection and associated modulated signaling scheme is not considered a bus, and is analogous to an Ethernet connection.

Compressed video is also carried using UDP-IP over Ethernet.

Ethernet is a family of computer networking technologies for local area networks ( LANs ).

In addition to computers, Ethernet is now used to interconnect appliances and other personal devices.

As with other IEEE 802 LANs, each Ethernet station is given a 48-bit MAC address.

When a twisted pair or fiber link segment is used and neither end is connected to a repeater, full-duplex Ethernet becomes possible over that segment.

Since packets are typically delivered only to the port they are intended for, traffic on a switched Ethernet is less public than on shared-medium Ethernet.

< span id =" switch_vulnerabilities "> Despite this, switched Ethernet should still be regarded as an insecure network technology, because it is easy to subvert switched Ethernet systems by means such as ARP spoofing and MAC flooding .</ span >

Simple switched Ethernet networks, while a great improvement over repeater-based Ethernet, suffer from single points of failure, attacks that trick switches or hosts into sending data to a machine even if it is not intended for it, scalability and security issues with regard to broadcast radiation and multicast traffic, and bandwidth choke points where a lot of traffic is forced down a single link.

IEEE 802. 3 is a working group and a collection of IEEE standards produced by the working group defining the physical layer and data link layer's media access control ( MAC ) of wired Ethernet.

Beneath the LLC sublayer is the Media Access Control ( MAC ) sublayer, which is dependent on the particular medium being used ( Ethernet, token ring, FDDI, 802. 11, etc.