634:= 0x4C11DB7, initial CRC = 0xFFFFFFFF, CRC is post complemented, verify value = 0x38FB2284) algorithm. The standard states that data is transmitted least significant bit (bit 0) first, while the FCS is transmitted most significant bit (bit 31) first. An alternative is to calculate a CRC using the right shifting CRC-32 (polynomial = 0xEDB88320, initial CRC = 0xFFFFFFFF, CRC is post complemented, verify value = 0x2144DF1C), which will result in a CRC that is a bit reversal of the FCS, and transmit both data and the CRC least significant bit first, resulting in identical transmissions.
897:
Ethernet 802.3 frame is 1500 octets (0x05DC). Thus if the field's value is greater than or equal to 1536, the frame must be an
Ethernet II frame, with that field being a type field. If it's less than or equal to 1500, it must be an IEEE 802.3 frame, with that field being a length field. Values between 1500 and 1536, exclusive, are undefined. This convention allows software to determine whether a frame is an Ethernet II frame or an IEEE 802.3 frame, allowing the coexistence of both standards on the same physical medium.
876:
2387:
22:
2399:
1954:
1933:
627:(CRC) that allows detection of corrupted data within the entire frame as received on the receiver side. According to the standard, the FCS value is computed as a function of the protected MAC frame fields: source and destination address, length/type field, MAC client data and padding (that is, all fields except the FCS).
1957:
638:
result is non-zero because the CRC is post complemented during CRC generation). Since the data is received least significant bit first, and to avoid having to buffer octets of data, the receiver typically uses the right shifting CRC-32. This makes the "verify" value (sometimes called "magic check") 0x2144DF1C.
1956:
1961:
1960:
1955:
1962:
645:
as the basis for calculating the CRC, reversing the bits and resulting in a verify value of 0x38FB2284. Since the complementing of the CRC may be performed post calculation and during transmission, what remains in the hardware register is a non-complemented result, so the residue for a right shifting
558:
The EtherType field is two octets long and it can be used for two different purposes. Values of 1500 and below mean that it is used to indicate the size of the payload in octets, while values of 1536 and above indicate that it is used as an EtherType, to indicate which protocol is encapsulated in the
809:
The IEEE 802.1Q tag, if present, is placed between the Source
Address and the EtherType or Length fields. The first two octets of the tag are the Tag Protocol Identifier (TPID) value of 0x8100. This is located in the same place as the EtherType/Length field in untagged frames, so an EtherType value
606:
Payload is a variable-length field. Its minimum size is governed by a requirement for a minimum frame transmission of 64 octets (bytes). With header and FCS taken into account, the minimum payload is 42 octets when an 802.1Q tag is present and 46 octets when absent. When the actual payload is less
896:
In order to allow some frames using
Ethernet II framing and some using the original version of 802.3 framing to be used on the same Ethernet segment, EtherType values must be greater than or equal to 1536 (0x0600). That value was chosen because the maximum length of the payload field of an
637:
The standard states that the receiver should calculate a new FCS as data is received and then compare the received FCS with the FCS the receiver has calculated. An alternative is to calculate a CRC on both the received data and the FCS, which will result in a fixed non-zero "verify" value. (The
1276:
is a concept often confused with protocol efficiency. It considers only the use of the channel disregarding the nature of the data transmitted – either payload or overhead. At the physical layer, the link channel and equipment do not know the difference between data and control frames. We may
909:
Network
Protocol over Ethernet. They did not use any LLC header but started the IPX packet directly after the length field. This does not conform to the IEEE 802.3 standard, but since IPX always has FF as the first two octets (while in IEEE 802.2 LLC that pattern is theoretically possible but
892:
header to follow the length and specify the type. Many years later, the 802.3x-1997 standard, and later versions of the 802.3 standard, formally approved of both types of framing. Ethernet II framing is the most common in
Ethernet local area networks, due to its simplicity and lower overhead.
920:
used this frame type by default until the mid-nineties, and since NetWare was then very widespread, while IP was not, at some point in time most of the world's
Ethernet traffic ran over "raw" 802.3 carrying IPX. Since NetWare 4.10, NetWare defaults to IEEE 802.2 with LLC (NetWare Frame Type
1936:
287:(SFD). The preamble bit values alternate 1 and 0, allowing receivers to synchronize their clock at the bit-level with the transmitter. The preamble is followed by the SFD which ends with a 1 instead of 0, to break the bit pattern of the preamble and signal the start of the actual frame.
1935:
1940:
1939:
1934:
1941:
1959:
995:(SAPs) in OSI terminology; when both source and destination SAP are set to the value 0xAA, the LLC header is followed by a SNAP header. The SNAP header allows EtherType values to be used with all IEEE 802 protocols, as well as supporting private protocol ID spaces.
1069:
1938:
1317:
1410:, which is where packet sniffers collect their data. There are layer-2 sniffers that can capture and display the preamble and start frame delimiter, but they are expensive and mainly used to detect problems related to physical connectivity.
1114:
1252:
1161:
for untagged frames, since the packet size is maximum 1500 octet payload + 8 octet preamble + 14 octet header + 4 octet trailer + minimum interpacket gap corresponding to 12 octets = 1538 octets. The maximum efficiency is:
1322:
The total time considers the round trip time along the channel, the processing time in the hosts and the time transmitting data and acknowledgements. The time spent transmitting data includes data and acknowledgements.
1583:
Opcodes are transmitted high-order octet first. Within each octet, bits are transmitted least-significant bit first. Each octet of the MAC frame, with the exception of the FCS, is transmitted least significant bit
293:(PHY for short) is required to connect the Ethernet MAC to the physical medium. The connection between a PHY and MAC is independent of the physical medium and uses a bus from the media independent interface family (
1958:
887:
standardization process, the EtherType field was changed to a (data) length field in the new 802.3 standard. Since the recipient still needs to know how to interpret the frame, the standard required an
810:
of 0x8100 means the frame is tagged, and the true EtherType/Length is located after the Q-tag. The TPID is followed by two octets containing the Tag
Control Information (TCI) (the IEEE 802.1p priority (
1937:
1847:) — a classic series of Usenet postings by Novell's Don Provan that have found their way into numerous FAQs and are widely considered the definitive answer to the Novell Frame Type usage.
685:(IPG) is idle time between packets. After a packet has been sent, transmitters are required to transmit a minimum of 96 bits (12 octets) of idle line state before transmitting the next packet.
108:
The internal structure of an
Ethernet frame is specified in IEEE 802.3. The table below shows the complete Ethernet packet and the frame inside, as transmitted, for the payload size up to the
1199:
1156:
1027:
25:
Ethernet packet. The SFD (start frame delimiter) marks the end of the packet preamble. It is immediately followed by the
Ethernet frame, which starts with the destination MAC address.
1629:
1287:
998:
In IEEE 802.3x-1997, the IEEE Ethernet standard was changed to explicitly allow the use of the 16-bit field after the MAC addresses to be used as a length field or a type field.
598:
entifier (TPID) and double as the EtherType field indicating that the frame is either 802.1Q or 802.1ad tagged. 802.1Q uses a TPID of 0x8100. 802.1ad uses a TPID of 0x88a8.
991:
By examining the 802.2 LLC header, it is possible to determine whether it is followed by a SNAP header. The LLC header includes two eight-bit address fields, called
1084:
2173:
1420:
1217:
910:
extremely unlikely), in practice this usually coexists on the wire with other
Ethernet implementations, with the notable exception of some early forms of
905:
Novell's "raw" 802.3 frame format was based on early IEEE 802.3 work. Novell used this as a starting point to create the first implementation of its own
965:
for encapsulating IPv4 traffic in IEEE 802.2 LLC SAP/SNAP frames. It is almost never implemented on Ethernet, although it is used on FDDI, Token Ring,
646:
implementation would be the complement of 0x2144DF1C = 0xDEBB20E3, and for a left shifting implementation, the complement of 0x38FB2284 = 0xC704DD7B.
759:
Ethernet II frame, or Ethernet Version 2, or DIX frame is the most common type in use today, as it is often used directly by the Internet Protocol.
1380:
as octet values, which in Ethernet are transmitted least significant bit(s) first). This notation matches the one used in the IEEE 802.3 standard.
670:
symbol or sequence to avoid ambiguity, especially where the carrier is continually sent between frames; an example is Gigabit Ethernet with its
798:
In addition, all four Ethernet frame types may optionally contain an IEEE 802.1Q tag to identify what VLAN it belongs to and its priority (
1840:
1331:
A runt frame is an Ethernet frame that is less than the IEEE 802.3's minimum length of 64 octets. Runt frames are most commonly caused by
1640:
939:, operate directly on top of IEEE 802.2 LLC encapsulation, which provides both connection-oriented and connectionless network services.
1441:
A version 1 Ethernet frame was used for early Ethernet prototypes and featured 8-bit MAC addresses and was never commercially deployed.
1376:
The bit patterns in the preamble and start of frame delimiter are written as bit strings, with the first bit transmitted on the left (
795:
values, but can coexist on the same physical medium. Differentiation between frame types is possible based on the table on the right.
256:
The optional 802.1Q tag consumes additional space in the frame. Field sizes for this option are shown in brackets in the table above.
662:, where the receiving station detects the end of a transmitted frame by loss of the carrier. Later physical layers use an explicit
1598:
IEEE Standard for Local and metropolitan area networks--Media Access Control (MAC) Bridges and Virtual Bridged Local Area Networks
101:
A data packet on the wire and the frame as its payload consist of binary data. Ethernet transmits data with the most-significant
75:
as its first two fields. The middle section of the frame is payload data including any headers for other protocols (for example,
2367:
607:
than the minimum, padding octets are added accordingly. IEEE standards specify a maximum payload of 1500 octets. Non-standard
1799:
1751:
1726:
1613:
1576:
1540:
1500:
1816:
658:
is usually indicated by the end-of-data-stream symbol at the physical layer or by loss of the carrier signal; an example is
642:
1450:
Original Ethernet frames define their length with the framing that surrounds it, rather than with an explicit length count.
942:
IEEE 802.2 LLC encapsulation is not in widespread use on common networks currently, with the exception of large corporate
2362:
1994:
950:. In the past, many corporate networks used IEEE 802.2 to support transparent translating bridges between Ethernet and
977:
LANs. IPv6 can also be transmitted over Ethernet using IEEE 802.2 LLC SAP/SNAP, but, again, that's almost never used.
1682:
1905:
1892:
IEEE Std 802.11-2016: Part 11: Wireless LAN Medium Access Control IEEE (MAC) and Physical Layer (PHY) Specifications
1064:{\displaystyle {\text{Protocol overhead}}={\frac {{\text{Packet size}}-{\text{Payload size}}}{\text{Packet size}}}}
1168:
1125:
2213:
1332:
631:
1312:{\displaystyle {\text{Channel utilization}}={\frac {\text{Time spent transmitting data}}{\text{Total time}}}}
1270:
for 100BASE-TX Ethernet is consequently 97.53 Mbit/s without 802.1Q, and 97.28 Mbit/s with 802.1Q.
830:
1403:
559:
payload of the frame. When used as EtherType, the length of the frame is determined by the location of the
2357:
2307:
2302:
1006:
861:
674:
encoding scheme that uses special symbols which are transmitted before and after a frame is transmitted.
461:
294:
814:) and VLAN id). The Q-tag is followed by the rest of the frame, using one of the types described above.
2352:
2150:
2140:
986:
853:
846:
784:
2403:
2342:
2264:
1972:
792:
341:
transmitted from left to right (used by Ethernet variants transmitting serial bits instead of larger
109:
856:
by the frame data. Most notably, an EtherType value of 0x0800 indicates that the frame contains an
280:
96:
64:
2326:
2073:
2037:
1263:
624:
171:
84:
45:
2208:
1987:
1837:
1832:
1674:
1109:{\displaystyle {\text{Protocol efficiency}}={\frac {\text{Payload size}}{\text{Packet size}}}}
2088:
378:
71:. Each Ethernet frame starts with an Ethernet header, which contains destination and source
2284:
2259:
2052:
1873:
1364:
850:
775:
641:
However, hardware implementation of a logically right shifting CRC may use a left shifting
620:
564:
167:
80:
543:
The header features destination and source MAC addresses (each six octets in length), the
105:(byte) first; within each octet, however, the least-significant bit is transmitted first.
8:
2279:
2269:
2249:
2244:
2228:
2135:
2047:
2042:
1828:
1278:
1273:
1766:
2145:
2007:
1667:
1267:
1266:
standard, and may be 10 Mbit/s, 100 Mbit/s, 1 Gbit/s or 10 Gbit/s.
1247:{\displaystyle {\text{Throughput}}={\text{Efficiency}}\times {\text{Net bit rate}}\,\!}
811:
799:
60:
41:
260:(Q-in-Q) allows for multiple tags in each frame. This option is not illustrated here.
2425:
2391:
2119:
1980:
1795:
1747:
1722:
1678:
1609:
1572:
1536:
1496:
1018:
962:
947:
185:
102:
76:
2254:
2057:
2032:
2022:
1863:
1820:
1787:
1714:
1601:
1564:
1528:
1488:
1389:
Payload can be 42 octets if an 802.1Q tag is present. Minimum is 46 octets without.
421:
113:
67:
and start frame delimiter (SFD), which are both part of the Ethernet packet at the
30:
2321:
2078:
1844:
1791:
1718:
1605:
1568:
1532:
1492:
1399:
1344:
1340:
682:
560:
177:
38:
1876:
1857:
875:
2316:
2274:
917:
68:
49:
2419:
2027:
1824:
1771:. The Institute of Electrical and Electronics Engineers, Inc. pp. 28–31.
465:
342:
869:
116:
and other higher-speed variants of Ethernet support larger frames, known as
1336:
1259:
970:
803:
630:
Per the standard, this computation is done using the left shifting CRC-32 (
575:
552:
257:
1767:
LAN MAN Standards Committee of the IEEE Computer Society (20 March 1997).
2294:
2098:
1407:
1119:
Maximum efficiency is achieved with largest allowed payload size and is:
966:
608:
583:
579:
571:
548:
527:
154:
117:
72:
313:). The preamble and SFD representation depends on the width of the bus:
2347:
2114:
1208:
951:
930:
889:
849:, preceded by destination and source MAC addresses, that identifies an
781:
772:
766:
158:
2002:
1859:
A Standard for the Transmission of IP Datagrams over IEEE 802 Networks
317:
Preamble and SFD representations as bits, decimal, bytes, and nibbles
2223:
2218:
2193:
2188:
2183:
2083:
1868:
1002:
936:
842:
544:
150:
1402:
software because these bits are stripped away at OSI layer 1 by the
2155:
2003:
1419:
Minimum payload size is dictated by the 512-bit slot time used for
974:
659:
274:
53:
2203:
2198:
2178:
1636:
943:
239:
220:
21:
2312:
1432:
Both 42 and 46 octet minimums are valid when 802.1Q is present.
911:
841:, the major participants in its design), defines the two-octet
762:
671:
455:
144:
838:
834:
611:
allow for larger payloads on networks built to support them.
469:
310:
306:
302:
2372:
1710:
1560:
1524:
1484:
955:
884:
865:
857:
806:
specification and increases the maximum frame by 4 octets.
417:
298:
883:
As this industry-developed standard went through a formal
1514:
1512:
1021:
for Ethernet as a percentage (packet size including IPG)
946:
installations that have not yet migrated to NetWare over
906:
586:
priority. The first two octets of the tag are called the
290:
1741:
1398:
Preamble and start frame delimiter are not displayed by
1509:
578:
tag, if present, is a four-octet field that indicates
279:
An Ethernet packet starts with a seven-octet (56-bit)
1290:
1220:
1171:
1128:
1087:
1030:
791:
The different frame types have different formats and
268:
1862:. Network Working Group of the IETF. February 1988.
1947:
Video which explains how to build an Ethernet Frame
1664:
677:
526:The SFD is immediately followed by the destination
263:
1666:
1311:
1246:
1193:
1150:
1108:
1063:
87:used to detect any in-transit corruption of data.
56:link transports an Ethernet frame as its payload.
1630:"Specification of CRC Routines V4.5.0 R4.1 Rev 3"
1243:
530:, which is the first field in an Ethernet frame.
2417:
1889:
649:
935:Some protocols, such as those designed for the
879:The most common Ethernet frame format, type II
79:) carried in the frame. The frame ends with a
1988:
1769:IEEE Std 802.3x-1997 and IEEE Std 802.3y-1997
1335:; other possible causes are a malfunctioning
1009:") uses IEEE 802.2 LLC + SNAP encapsulation.
1744:Drew Heywood's Windows 2000 Network Services
1475:
1473:
1471:
1469:
1467:
1194:{\displaystyle {\frac {1500}{1542}}=97.28\%}
1151:{\displaystyle {\frac {1500}{1538}}=97.53\%}
755:There are several types of Ethernet frames:
1705:"40.1.3.1 Physical Coding Sublayer (PCS)".
1563:. 14 June 2018. Section 3.3 and annex 31A.
1995:
1981:
1968:Minimum Frame Length in Ethernet explained
1814:
533:
124:802.3 Ethernet packet and frame structure
1867:
1464:
1242:
900:
874:
802:). This encapsulation is defined in the
112:of 1500 octets. Some implementations of
48:transport mechanisms. In other words, a
20:
1784:802.3-2018 – IEEE Standard for Ethernet
1707:802.3-2018 – IEEE Standard for Ethernet
1557:802.3-2018 – IEEE Standard for Ethernet
1521:802.3-2018 – IEEE Standard for Ethernet
1481:802.3-2018 – IEEE Standard for Ethernet
614:
2418:
1211:may be calculated from the efficiency
1976:
1665:Charles E. Spurgeon (February 2000).
1012:
973:, where it uses EtherType) and other
2398:
1406:(NIC) before being passed on to the
1367:(FCS) uses a different bit ordering.
291:Physical layer transceiver circuitry
1742:Drew Heywood; Zubair Ahmad (2001).
1262:(the wire bit rate) depends on the
16:Unit of data on an Ethernet network
13:
2058:200, 400, 800 and 1600 Gbit/s
1924:
1894:. New York, NY: IEEE. p. 249.
1204:when 802.1Q VLAN tagging is used.
1188:
1145:
980:
864:datagram, and 0x86DD indicates an
269:Preamble and start frame delimiter
14:
2437:
1423:in the Ethernet LAN architecture.
924:
2397:
2386:
2385:
1952:
1931:
1815:Don Provan (17 September 1993).
1005:v2 protocol suite on Ethernet ("
921:Ethernet_802.2) when using IPX.
678:Interpacket gap – physical layer
264:Ethernet packet – physical layer
1898:
1890:Computer Society, IEEE (2016).
1883:
1850:
1808:
1775:
1760:
1735:
1698:
1658:
1622:
1444:
1435:
1426:
694:Ethernet frame differentiation
1669:Ethernet: The Definitive Guide
1589:
1549:
1413:
1392:
1383:
1370:
1357:
1326:
860:datagram, 0x0806 indicates an
817:
643:Linear Feedback Shift Register
1:
1457:
650:End of frame – physical layer
1792:10.1109/IEEESTD.2018.8457469
1719:10.1109/IEEESTD.2018.8457469
1639:. p. 24. Archived from
1606:10.1109/IEEESTD.2011.6009146
1569:10.1109/IEEESTD.2018.8457469
1533:10.1109/IEEESTD.2018.8457469
1493:10.1109/IEEESTD.2018.8457469
1404:network interface controller
1302:Time spent transmitting data
914:which got confused by this.
769:non-standard variation frame
90:
7:
1782:"3.2.6 Length/Type field".
969:(with the exception of the
135:Start frame delimiter (SFD)
10:
2442:
1906:"Troubleshooting Ethernet"
987:Subnetwork Access Protocol
984:
928:
785:Subnetwork Access Protocol
601:
547:field and, optionally, an
472:for gigabit transceivers)
324:
272:
242:Ethernet packet & IPG
178:Interpacket gap (IPG)
94:
2381:
2335:
2293:
2237:
2166:
2128:
2107:
2066:
2015:
1258:where the physical layer
538:
448:
445:
442:
439:
436:
433:
430:
427:
404:
401:
398:
395:
392:
389:
386:
383:
368:
365:
362:
359:
356:
353:
350:
347:
329:
244:
228:
225:
83:(FCS), which is a 32-bit
2308:SFP/SFP+/QSFP/QSFP+/OSFP
1350:
705:Payload start two bytes
688:
326:56-bit (7-byte) Preamble
234:(not part of the frame)
97:Physical Coding Sublayer
44:and uses the underlying
1519:"3.1.1 Packet format".
1264:Ethernet physical layer
870:EtherType § Values
625:cyclic redundancy check
534:Frame – data link layer
460:for 4-bit wide busses (
226:(not part of the frame)
85:cyclic redundancy check
46:Ethernet physical layer
2053:40 and 100 Gbit/s
1838:HTML-formatted version
1313:
1248:
1195:
1152:
1110:
1065:
880:
623:(FCS) is a four-octet
582:(VLAN) membership and
454:hexadecimal LSb-first
414:for 8-bit wide busses
410:hexadecimal LSb-first
283:and one-octet (8-bit)
26:
2048:25 and 50 Gbit/s
2038:2.5 and 5 Gbit/s
1843:18 April 2015 at the
1673:. O'Reilly. pp.
1314:
1249:
1196:
1153:
1111:
1074:We may calculate the
1066:
1017:We may calculate the
993:service access points
901:Novell raw IEEE 802.3
878:
845:field in an Ethernet
721:Novell raw IEEE 802.3
285:start frame delimiter
24:
1746:. Sams. p. 53.
1365:frame check sequence
1347:or software issues.
1288:
1218:
1169:
1126:
1085:
1028:
851:upper layer protocol
776:Logical Link Control
621:frame check sequence
615:Frame check sequence
565:frame check sequence
337:uncoded on-the-wire
168:Frame check sequence
81:frame check sequence
1421:collision detection
1293:Channel utilization
1279:channel utilization
1274:Channel utilization
1090:Protocol efficiency
1076:protocol efficiency
823:Ethernet II framing
702:Ethertype or length
695:
318:
250:← 12 octets →
125:
31:computer networking
2008:local area network
1817:"Ethernet Framing"
1309:
1268:Maximum throughput
1244:
1191:
1148:
1106:
1061:
1013:Maximum throughput
881:
812:quality of service
800:quality of service
693:
316:
246:← 72–1530 octets →
230:← 64–1522 octets →
157:) or length (
123:
42:protocol data unit
27:
2413:
2412:
2265:Energy Efficiency
2120:Ethernet Alliance
1963:
1942:
1801:978-1-5044-5090-4
1753:978-0-672-31741-5
1728:978-1-5044-5090-4
1615:978-0-7381-6708-4
1578:978-1-5044-5090-4
1542:978-1-5044-5090-4
1502:978-1-5044-5090-4
1307:
1306:
1303:
1294:
1240:
1232:
1224:
1180:
1137:
1104:
1103:
1100:
1091:
1059:
1058:
1053:
1045:
1034:
1033:Protocol overhead
1019:protocol overhead
963:Internet standard
753:
752:
524:
523:
254:
253:
77:Internet Protocol
63:is preceded by a
2433:
2401:
2400:
2389:
2388:
1997:
1990:
1983:
1974:
1973:
1965:
1964:
1944:
1943:
1918:
1917:
1915:
1913:
1902:
1896:
1895:
1887:
1881:
1880:
1871:
1869:10.17487/RFC1042
1854:
1848:
1835:
1812:
1806:
1805:
1786:. 14 June 2018.
1779:
1773:
1772:
1764:
1758:
1757:
1739:
1733:
1732:
1713:. 14 June 2018.
1702:
1696:
1695:
1693:
1691:
1672:
1662:
1656:
1655:
1653:
1651:
1645:
1634:
1626:
1620:
1619:
1593:
1587:
1586:
1553:
1547:
1546:
1527:. 14 June 2018.
1516:
1507:
1506:
1487:. 14 June 2018.
1477:
1451:
1448:
1442:
1439:
1433:
1430:
1424:
1417:
1411:
1396:
1390:
1387:
1381:
1374:
1368:
1361:
1318:
1316:
1315:
1310:
1308:
1304:
1301:
1300:
1295:
1292:
1253:
1251:
1250:
1245:
1241:
1238:
1233:
1230:
1225:
1222:
1200:
1198:
1197:
1192:
1181:
1173:
1157:
1155:
1154:
1149:
1138:
1130:
1115:
1113:
1112:
1107:
1105:
1101:
1098:
1097:
1092:
1089:
1070:
1068:
1067:
1062:
1060:
1056:
1055:
1054:
1051:
1046:
1043:
1040:
1035:
1032:
961:There exists an
696:
692:
422:Gigabit Ethernet
381:-first ordering
319:
315:
247:
231:
155:Ethernet II
126:
122:
114:Gigabit Ethernet
2441:
2440:
2436:
2435:
2434:
2432:
2431:
2430:
2416:
2415:
2414:
2409:
2377:
2331:
2289:
2233:
2162:
2124:
2103:
2079:Autonegotiation
2062:
2028:100 Mbit/s
2011:
2001:
1969:
1966:
1953:
1948:
1945:
1932:
1927:
1925:Further reading
1922:
1921:
1911:
1909:
1908:. Cisco Systems
1904:
1903:
1899:
1888:
1884:
1856:
1855:
1851:
1845:Wayback Machine
1825:comp.sys.novell
1813:
1809:
1802:
1781:
1780:
1776:
1765:
1761:
1754:
1740:
1736:
1729:
1704:
1703:
1699:
1689:
1687:
1685:
1663:
1659:
1649:
1647:
1646:on 11 June 2020
1643:
1632:
1628:
1627:
1623:
1616:
1595:
1594:
1590:
1579:
1555:
1554:
1550:
1543:
1518:
1517:
1510:
1503:
1479:
1478:
1465:
1460:
1455:
1454:
1449:
1445:
1440:
1436:
1431:
1427:
1418:
1414:
1400:packet sniffing
1397:
1393:
1388:
1384:
1375:
1371:
1362:
1358:
1353:
1345:duplex mismatch
1341:buffer underrun
1329:
1299:
1291:
1289:
1286:
1285:
1237:
1229:
1221:
1219:
1216:
1215:
1172:
1170:
1167:
1166:
1129:
1127:
1124:
1123:
1096:
1088:
1086:
1083:
1082:
1050:
1042:
1041:
1039:
1031:
1029:
1026:
1025:
1015:
989:
983:
981:IEEE 802.2 SNAP
933:
927:
903:
825:(also known as
820:
743:IEEE 802.2 SNAP
691:
683:Interpacket gap
680:
652:
617:
604:
561:interpacket gap
541:
536:
322:Representation
277:
271:
266:
245:
229:
223:Ethernet frame
159:IEEE 802.3
138:MAC destination
99:
93:
39:data link layer
17:
12:
11:
5:
2439:
2429:
2428:
2411:
2410:
2408:
2407:
2395:
2382:
2379:
2378:
2376:
2375:
2370:
2365:
2360:
2355:
2350:
2345:
2339:
2337:
2333:
2332:
2330:
2329:
2324:
2319:
2310:
2305:
2299:
2297:
2291:
2290:
2288:
2287:
2282:
2277:
2272:
2267:
2262:
2257:
2252:
2247:
2241:
2239:
2235:
2234:
2232:
2231:
2226:
2221:
2216:
2211:
2206:
2201:
2196:
2191:
2186:
2181:
2176:
2170:
2168:
2164:
2163:
2161:
2160:
2159:
2158:
2148:
2143:
2138:
2132:
2130:
2126:
2125:
2123:
2122:
2117:
2111:
2109:
2105:
2104:
2102:
2101:
2096:
2091:
2086:
2081:
2076:
2074:Physical layer
2070:
2068:
2064:
2063:
2061:
2060:
2055:
2050:
2045:
2043:10 Gbit/s
2040:
2035:
2030:
2025:
2023:10 Mbit/s
2019:
2017:
2013:
2012:
2000:
1999:
1992:
1985:
1977:
1971:
1970:
1967:
1951:
1949:
1946:
1930:
1926:
1923:
1920:
1919:
1897:
1882:
1849:
1807:
1800:
1774:
1759:
1752:
1734:
1727:
1697:
1683:
1657:
1621:
1614:
1588:
1577:
1548:
1541:
1508:
1501:
1462:
1461:
1459:
1456:
1453:
1452:
1443:
1434:
1425:
1412:
1391:
1382:
1369:
1355:
1354:
1352:
1349:
1328:
1325:
1320:
1319:
1298:
1277:calculate the
1256:
1255:
1236:
1228:
1202:
1201:
1190:
1187:
1184:
1179:
1176:
1159:
1158:
1147:
1144:
1141:
1136:
1133:
1117:
1116:
1095:
1072:
1071:
1049:
1038:
1014:
1011:
985:Main article:
982:
979:
929:Main article:
926:
925:IEEE 802.2 LLC
923:
918:Novell NetWare
902:
899:
868:datagram. See
829:, named after
819:
816:
789:
788:
779:
770:
760:
751:
750:
747:
744:
740:
739:
736:
733:
732:IEEE 802.2 LLC
729:
728:
725:
722:
718:
717:
714:
711:
707:
706:
703:
700:
690:
687:
679:
676:
656:end of a frame
651:
648:
616:
613:
603:
600:
540:
537:
535:
532:
522:
521:
518:
515:
512:
509:
506:
503:
500:
497:
494:
491:
488:
485:
482:
479:
476:
473:
451:
450:
447:
444:
441:
438:
435:
432:
429:
426:
424:transceivers)
407:
406:
403:
400:
397:
394:
391:
388:
385:
382:
371:
370:
367:
364:
361:
358:
355:
352:
349:
346:
334:
333:
328:
323:
270:
267:
265:
262:
252:
251:
248:
243:
236:
235:
232:
227:
224:
217:
216:
213:
210:
207:
204:
201:
198:
195:
192:
189:
181:
180:
175:
165:
162:
148:
147:tag (optional)
142:
139:
136:
133:
130:
92:
89:
69:physical layer
35:Ethernet frame
15:
9:
6:
4:
3:
2:
2438:
2427:
2424:
2423:
2421:
2406:
2405:
2396:
2394:
2393:
2384:
2383:
2380:
2374:
2371:
2369:
2366:
2364:
2361:
2359:
2356:
2354:
2351:
2349:
2346:
2344:
2341:
2340:
2338:
2334:
2328:
2325:
2323:
2320:
2318:
2314:
2311:
2309:
2306:
2304:
2301:
2300:
2298:
2296:
2292:
2286:
2283:
2281:
2278:
2276:
2273:
2271:
2268:
2266:
2263:
2261:
2258:
2256:
2253:
2251:
2248:
2246:
2243:
2242:
2240:
2236:
2230:
2227:
2225:
2222:
2220:
2217:
2215:
2212:
2210:
2207:
2205:
2202:
2200:
2197:
2195:
2192:
2190:
2187:
2185:
2182:
2180:
2177:
2175:
2172:
2171:
2169:
2165:
2157:
2154:
2153:
2152:
2149:
2147:
2144:
2142:
2139:
2137:
2134:
2133:
2131:
2127:
2121:
2118:
2116:
2113:
2112:
2110:
2108:Organizations
2106:
2100:
2097:
2095:
2092:
2090:
2087:
2085:
2082:
2080:
2077:
2075:
2072:
2071:
2069:
2065:
2059:
2056:
2054:
2051:
2049:
2046:
2044:
2041:
2039:
2036:
2034:
2033:1 Gbit/s
2031:
2029:
2026:
2024:
2021:
2020:
2018:
2014:
2009:
2005:
1998:
1993:
1991:
1986:
1984:
1979:
1978:
1975:
1950:
1929:
1928:
1907:
1901:
1893:
1886:
1878:
1875:
1870:
1865:
1861:
1860:
1853:
1846:
1842:
1839:
1833:
1830:
1826:
1822:
1818:
1811:
1803:
1797:
1793:
1789:
1785:
1778:
1770:
1763:
1755:
1749:
1745:
1738:
1730:
1724:
1720:
1716:
1712:
1708:
1701:
1686:
1684:9780596552824
1680:
1676:
1671:
1670:
1661:
1642:
1638:
1631:
1625:
1617:
1611:
1607:
1603:
1599:
1592:
1585:
1580:
1574:
1570:
1566:
1562:
1558:
1552:
1544:
1538:
1534:
1530:
1526:
1522:
1515:
1513:
1504:
1498:
1494:
1490:
1486:
1482:
1476:
1474:
1472:
1470:
1468:
1463:
1447:
1438:
1429:
1422:
1416:
1409:
1405:
1401:
1395:
1386:
1379:
1373:
1366:
1360:
1356:
1348:
1346:
1342:
1338:
1334:
1324:
1296:
1284:
1283:
1282:
1280:
1275:
1271:
1269:
1265:
1261:
1234:
1226:
1214:
1213:
1212:
1210:
1205:
1185:
1182:
1177:
1174:
1165:
1164:
1163:
1142:
1139:
1134:
1131:
1122:
1121:
1120:
1093:
1081:
1080:
1079:
1078:for Ethernet
1077:
1047:
1036:
1024:
1023:
1022:
1020:
1010:
1008:
1004:
999:
996:
994:
988:
978:
976:
972:
968:
964:
959:
957:
953:
949:
945:
940:
938:
932:
922:
919:
915:
913:
908:
898:
894:
891:
886:
877:
873:
871:
867:
863:
859:
855:
852:
848:
844:
840:
836:
832:
828:
824:
815:
813:
807:
805:
801:
796:
794:
786:
783:
780:
777:
774:
771:
768:
764:
761:
758:
757:
756:
748:
745:
742:
741:
737:
734:
731:
730:
726:
723:
720:
719:
715:
712:
709:
708:
704:
701:
698:
697:
686:
684:
675:
673:
669:
668:end of stream
665:
661:
657:
647:
644:
639:
635:
633:
628:
626:
622:
612:
610:
599:
597:
593:
589:
585:
581:
577:
573:
568:
566:
562:
556:
554:
550:
546:
531:
529:
519:
516:
513:
510:
507:
504:
501:
498:
495:
492:
489:
486:
483:
480:
477:
474:
471:
467:
466:Fast Ethernet
463:
459:
458:
453:
452:
425:
423:
419:
413:
409:
408:
380:
376:
373:
372:
344:
340:
336:
335:
332:
327:
321:
320:
314:
312:
308:
304:
300:
296:
292:
288:
286:
282:
276:
261:
259:
249:
241:
238:
237:
233:
222:
219:
218:
214:
211:
208:
205:
202:
199:
196:
193:
190:
187:
183:
182:
179:
176:
173:
169:
166:
163:
160:
156:
152:
149:
146:
143:
140:
137:
134:
131:
128:
127:
121:
119:
115:
111:
106:
104:
98:
88:
86:
82:
78:
74:
73:MAC addresses
70:
66:
62:
57:
55:
51:
47:
43:
40:
36:
32:
23:
19:
2402:
2390:
2295:Transceivers
2238:Applications
2141:Twisted pair
2093:
2089:Flow control
2010:technologies
1910:. Retrieved
1900:
1891:
1885:
1858:
1852:
1810:
1783:
1777:
1768:
1762:
1743:
1737:
1706:
1700:
1688:. Retrieved
1668:
1660:
1648:. Retrieved
1641:the original
1624:
1597:
1591:
1582:
1556:
1551:
1520:
1480:
1446:
1437:
1428:
1415:
1394:
1385:
1377:
1372:
1359:
1337:network card
1330:
1321:
1272:
1260:net bit rate
1257:
1239:Net bit rate
1206:
1203:
1160:
1118:
1099:Payload size
1075:
1073:
1052:Payload size
1016:
1000:
997:
992:
990:
971:5.9 GHz band
960:
941:
934:
916:
904:
895:
882:
854:encapsulated
827:DIX Ethernet
826:
822:
821:
808:
804:IEEE 802.3ac
797:
790:
787:(SNAP) frame
754:
681:
667:
663:
655:
653:
640:
636:
629:
618:
609:jumbo frames
605:
595:
591:
587:
576:IEEE 802.1ad
569:
557:
553:IEEE 802.1ad
542:
525:
456:
415:
411:
377:in Ethernet
374:
338:
330:
325:
289:
284:
278:
258:IEEE 802.1ad
255:
118:jumbo frames
107:
100:
59:An Ethernet
58:
34:
28:
18:
2285:Synchronous
2260:Data center
1596:"Annex G".
1408:OSI layer 2
1327:Runt frames
1102:Packet size
1057:Packet size
1044:Packet size
967:IEEE 802.11
818:Ethernet II
778:(LLC) frame
710:Ethernet II
664:end of data
584:IEEE 802.1p
580:virtual LAN
572:IEEE 802.1Q
549:IEEE 802.1Q
528:MAC address
339:bit pattern
2336:Interfaces
2270:Industrial
2250:Automotive
2229:Long Reach
2151:First mile
2115:IEEE 802.3
2006:family of
1650:30 January
1458:References
1333:collisions
1305:Total time
1231:Efficiency
1223:Throughput
1209:throughput
958:networks.
952:Token Ring
931:IEEE 802.2
890:IEEE 802.2
872:for more.
782:IEEE 802.2
773:IEEE 802.2
767:IEEE 802.3
699:Frame type
632:polynomial
563:and valid
273:See also:
141:MAC source
95:See also:
2224:LattisNet
2219:100BaseVG
2194:10BASE-FL
2189:10BASE-FB
2184:10BROAD36
2084:EtherType
1912:13 August
1821:Newsgroup
1235:×
1189:%
1146:%
1048:−
1007:EtherTalk
1003:AppleTalk
937:OSI stack
843:EtherType
545:EtherType
369:10101011
366:10101010
363:10101010
360:10101010
357:10101010
354:10101010
351:10101010
348:10101010
151:Ethertype
91:Structure
50:data unit
2426:Ethernet
2420:Category
2392:Category
2167:Historic
2156:10G-EPON
2004:Ethernet
1841:Archived
975:IEEE 802
660:10BASE-T
594:rotocol
418:GMII bus
331:SFD byte
281:preamble
275:Syncword
184:Length (
170:(32‑bit
132:Preamble
65:preamble
54:Ethernet
2404:Commons
2255:Carrier
2204:10BASE2
2199:10BASE5
2179:StarLAN
2174:CSMA/CD
2146:Coaxial
2067:General
1829:Usenet:
1823::
1690:30 June
1637:AUTOSAR
944:NetWare
749:0xAAAA
727:0xFFFF
602:Payload
574:tag or
567:(FCS).
551:tag or
462:MII bus
457:nibbles
375:decimal
343:symbols
240:Layer 1
221:Layer 2
209:42–1500
164:Payload
2313:XENPAK
2099:Jumbos
2094:Frames
2016:Speeds
1831:
1798:
1750:
1725:
1681:
1677:, 47.
1612:
1584:first.
1575:
1539:
1499:
912:DECnet
763:Novell
746:≤ 1500
738:Other
735:≤ 1500
724:≤ 1500
713:≥ 1536
672:8b/10b
539:Header
186:octets
145:802.1Q
52:on an
2368:XGMII
2280:Power
2275:Metro
2245:Audio
2214:FOIRL
2136:Fiber
2129:Media
1644:(PDF)
1633:(PDF)
1351:Notes
1186:97.28
1143:97.53
847:frame
839:Xerox
835:Intel
689:Types
555:tag.
470:RGMII
449:0xD5
446:0x55
443:0x55
440:0x55
437:0x55
434:0x55
431:0x55
428:0x55
412:bytes
311:XGMII
307:SGMII
303:RGMII
129:Layer
103:octet
61:frame
37:is a
33:, an
2373:XAUI
2363:GMII
2303:GBIC
1914:2016
1877:1042
1796:ISBN
1748:ISBN
1723:ISBN
1711:IEEE
1692:2014
1679:ISBN
1652:2020
1610:ISBN
1573:ISBN
1561:IEEE
1537:ISBN
1525:IEEE
1497:ISBN
1485:IEEE
1363:The
1207:The
1178:1542
1175:1500
1135:1538
1132:1500
1001:The
956:FDDI
885:IEEE
866:IPv6
858:IPv4
837:and
765:raw
716:Any
654:The
619:The
570:The
520:0xD
517:0x5
514:0x5
511:0x5
508:0x5
505:0x5
502:0x5
499:0x5
496:0x5
493:0x5
490:0x5
487:0x5
484:0x5
481:0x5
478:0x5
475:0x5
464:for
420:for
405:213
299:GMII
2358:MII
2353:MDI
2348:EAD
2343:AUI
2327:CFP
2322:XFP
2209:MAU
1874:RFC
1864:doi
1788:doi
1715:doi
1602:doi
1565:doi
1529:doi
1489:doi
1378:not
954:or
907:IPX
862:ARP
831:DEC
793:MTU
666:or
590:ag
468:or
402:85
399:85
396:85
393:85
390:85
387:85
384:85
379:LSb
295:MII
215:12
203:(4)
172:CRC
110:MTU
29:In
2422::
2317:X2
1872:.
1827:.
1819:.
1794:.
1721:.
1709:.
1675:41
1635:.
1608:.
1600:.
1581:.
1571:.
1559:.
1535:.
1523:.
1511:^
1495:.
1483:.
1466:^
1343:,
1339:,
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