645:= 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.
908:
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.
887:
2398:
33:
2410:
1965:
1944:
638:(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).
1968:
649:
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.
1967:
1972:
1971:
1966:
1973:
656:
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
569:
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
820:
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
617:
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
907:
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
648:
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
1287:
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
920:
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
903:
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.
931:
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
1947:
298:(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.
1946:
1951:
1950:
1945:
1952:
1970:
1006:(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.
1080:
1949:
1328:
1421:, 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.
1125:
1263:
1172:
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:
1333:
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.
1594:
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
304:(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 (
1969:
898:
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
821:
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 (
1948:
1858:) — 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.
696:(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.
119:
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
1210:
1167:
1038:
36:
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.
1640:
1298:
1009:
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.
609:
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.
1002:
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
1095:
2184:
1431:
1228:
921:
extremely unlikely), in practice this usually coexists on the wire with other
Ethernet implementations, with the notable exception of some early forms of
916:
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
976:
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,
657:
implementation would be the complement of 0x2144DF1C = 0xDEBB20E3, and for a left shifting implementation, the complement of 0x38FB2284 = 0xC704DD7B.
770:
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.
1391:
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.
681:
symbol or sequence to avoid ambiguity, especially where the carrier is continually sent between frames; an example is Gigabit Ethernet with its
809:
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 (
1851:
1342:
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
1651:
950:, operate directly on top of IEEE 802.2 LLC encapsulation, which provides both connection-oriented and connectionless network services.
1452:
A version 1 Ethernet frame was used for early Ethernet prototypes and featured 8-bit MAC addresses and was never commercially deployed.
1387:
The bit patterns in the preamble and start of frame delimiter are written as bit strings, with the first bit transmitted on the left (
806:
values, but can coexist on the same physical medium. Differentiation between frame types is possible based on the table on the right.
267:
The optional 802.1Q tag consumes additional space in the frame. Field sizes for this option are shown in brackets in the table above.
673:, where the receiving station detects the end of a transmitted frame by loss of the carrier. Later physical layers use an explicit
1609:
IEEE Standard for Local and metropolitan area networks--Media Access Control (MAC) Bridges and Virtual Bridged Local Area Networks
112:
A data packet on the wire and the frame as its payload consist of binary data. Ethernet transmits data with the most-significant
86:
as its first two fields. The middle section of the frame is payload data including any headers for other protocols (for example,
2378:
618:
than the minimum, padding octets are added accordingly. IEEE standards specify a maximum payload of 1500 octets. Non-standard
1810:
1762:
1737:
1624:
1587:
1551:
1511:
1827:
669:
is usually indicated by the end-of-data-stream symbol at the physical layer or by loss of the carrier signal; an example is
653:
1461:
Original Ethernet frames define their length with the framing that surrounds it, rather than with an explicit length count.
953:
IEEE 802.2 LLC encapsulation is not in widespread use on common networks currently, with the exception of large corporate
2373:
2005:
961:. In the past, many corporate networks used IEEE 802.2 to support transparent translating bridges between Ethernet and
988:
LANs. IPv6 can also be transmitted over Ethernet using IEEE 802.2 LLC SAP/SNAP, but, again, that's almost never used.
1693:
1916:
1903:
IEEE Std 802.11-2016: Part 11: Wireless LAN Medium Access Control IEEE (MAC) and Physical Layer (PHY) Specifications
1075:{\displaystyle {\text{Protocol overhead}}={\frac {{\text{Packet size}}-{\text{Payload size}}}{\text{Packet size}}}}
1179:
1136:
2224:
1343:
17:
642:
1323:{\displaystyle {\text{Channel utilization}}={\frac {\text{Time spent transmitting data}}{\text{Total time}}}}
1281:
for 100BASE-TX Ethernet is consequently 97.53 Mbit/s without 802.1Q, and 97.28 Mbit/s with 802.1Q.
841:
1414:
570:
payload of the frame. When used as EtherType, the length of the frame is determined by the location of the
2368:
2318:
2313:
1017:
872:
685:
encoding scheme that uses special symbols which are transmitted before and after a frame is transmitted.
472:
305:
825:) and VLAN id). The Q-tag is followed by the rest of the frame, using one of the types described above.
2363:
2161:
2151:
997:
864:
857:
795:
2414:
2353:
2275:
1983:
803:
352:
transmitted from left to right (used by Ethernet variants transmitting serial bits instead of larger
120:
867:
by the frame data. Most notably, an EtherType value of 0x0800 indicates that the frame contains an
291:
107:
75:
2337:
2084:
2048:
1274:
635:
182:
95:
56:
2219:
1998:
1848:
1843:
1685:
1120:{\displaystyle {\text{Protocol efficiency}}={\frac {\text{Payload size}}{\text{Packet size}}}}
2099:
389:
82:. Each Ethernet frame starts with an Ethernet header, which contains destination and source
2295:
2270:
2063:
1884:
1375:
861:
786:
652:
However, hardware implementation of a logically right shifting CRC may use a left shifting
631:
575:
178:
91:
554:
The header features destination and source MAC addresses (each six octets in length), the
116:(byte) first; within each octet, however, the least-significant bit is transmitted first.
8:
2290:
2280:
2260:
2255:
2239:
2146:
2058:
2053:
1839:
1289:
1284:
1777:
2156:
2018:
1678:
1278:
1277:
standard, and may be 10 Mbit/s, 100 Mbit/s, 1 Gbit/s or 10 Gbit/s.
1258:{\displaystyle {\text{Throughput}}={\text{Efficiency}}\times {\text{Net bit rate}}\,\!}
822:
810:
71:
52:
271:(Q-in-Q) allows for multiple tags in each frame. This option is not illustrated here.
2436:
2402:
2130:
1991:
1806:
1758:
1733:
1689:
1620:
1583:
1547:
1507:
1029:
973:
958:
196:
113:
87:
2265:
2068:
2043:
2033:
1874:
1831:
1798:
1725:
1612:
1575:
1539:
1499:
1400:
Payload can be 42 octets if an 802.1Q tag is present. Minimum is 46 octets without.
432:
124:
78:
and start frame delimiter (SFD), which are both part of the Ethernet packet at the
41:
2332:
2089:
1855:
1802:
1729:
1616:
1579:
1543:
1503:
1410:
1355:
1351:
693:
571:
188:
49:
1887:
1868:
886:
2327:
2285:
928:
79:
60:
2430:
2038:
1835:
1782:. The Institute of Electrical and Electronics Engineers, Inc. pp. 28–31.
476:
353:
880:
127:
and other higher-speed variants of Ethernet support larger frames, known as
1347:
1270:
981:
814:
641:
Per the standard, this computation is done using the left shifting CRC-32 (
586:
563:
268:
1778:
LAN MAN Standards Committee of the IEEE Computer Society (20 March 1997).
2305:
2109:
1418:
1130:
Maximum efficiency is achieved with largest allowed payload size and is:
977:
619:
594:
590:
582:
559:
538:
165:
128:
83:
324:). The preamble and SFD representation depends on the width of the bus:
2358:
2125:
1219:
962:
941:
900:
860:, preceded by destination and source MAC addresses, that identifies an
792:
783:
777:
169:
2013:
1870:
A Standard for the Transmission of IP Datagrams over IEEE 802 Networks
328:
Preamble and SFD representations as bits, decimal, bytes, and nibbles
2234:
2229:
2204:
2199:
2194:
2094:
1879:
1013:
947:
853:
555:
161:
1413:
software because these bits are stripped away at OSI layer 1 by the
2166:
2014:
1430:
Minimum payload size is dictated by the 512-bit slot time used for
985:
670:
285:
64:
2214:
2209:
2189:
1647:
954:
250:
231:
32:
2323:
1443:
Both 42 and 46 octet minimums are valid when 802.1Q is present.
922:
852:, the major participants in its design), defines the two-octet
773:
682:
466:
155:
849:
845:
622:
allow for larger payloads on networks built to support them.
480:
321:
317:
313:
2383:
1721:
1571:
1535:
1495:
966:
895:
876:
868:
817:
specification and increases the maximum frame by 4 octets.
428:
309:
894:
As this industry-developed standard went through a formal
1525:
1523:
1032:
for Ethernet as a percentage (packet size including IPG)
957:
installations that have not yet migrated to NetWare over
917:
597:
priority. The first two octets of the tag are called the
301:
1752:
1409:
Preamble and start frame delimiter are not displayed by
1520:
589:
tag, if present, is a four-octet field that indicates
290:
An Ethernet packet starts with a seven-octet (56-bit)
1301:
1231:
1182:
1139:
1098:
1041:
802:
The different frame types have different formats and
279:
1873:. Network Working Group of the IETF. February 1988.
1958:
Video which explains how to build an Ethernet Frame
1675:
688:
537:The SFD is immediately followed by the destination
274:
1677:
1322:
1257:
1204:
1161:
1119:
1074:
98:used to detect any in-transit corruption of data.
67:link transports an Ethernet frame as its payload.
1641:"Specification of CRC Routines V4.5.0 R4.1 Rev 3"
1254:
541:, which is the first field in an Ethernet frame.
2428:
1900:
660:
946:Some protocols, such as those designed for the
890:The most common Ethernet frame format, type II
90:) carried in the frame. The frame ends with a
1999:
1780:IEEE Std 802.3x-1997 and IEEE Std 802.3y-1997
1346:; other possible causes are a malfunctioning
1020:") uses IEEE 802.2 LLC + SNAP encapsulation.
1755:Drew Heywood's Windows 2000 Network Services
1486:
1484:
1482:
1480:
1478:
1205:{\displaystyle {\frac {1500}{1542}}=97.28\%}
1162:{\displaystyle {\frac {1500}{1538}}=97.53\%}
766:There are several types of Ethernet frames:
1716:"40.1.3.1 Physical Coding Sublayer (PCS)".
1574:. 14 June 2018. Section 3.3 and annex 31A.
2006:
1992:
1979:Minimum Frame Length in Ethernet explained
1825:
544:
135:802.3 Ethernet packet and frame structure
1878:
1475:
1253:
911:
885:
813:). This encapsulation is defined in the
123:of 1500 octets. Some implementations of
59:transport mechanisms. In other words, a
31:
1795:802.3-2018 – IEEE Standard for Ethernet
1718:802.3-2018 – IEEE Standard for Ethernet
1568:802.3-2018 – IEEE Standard for Ethernet
1532:802.3-2018 – IEEE Standard for Ethernet
1492:802.3-2018 – IEEE Standard for Ethernet
625:
14:
2429:
1222:may be calculated from the efficiency
1987:
1676:Charles E. Spurgeon (February 2000).
1023:
984:, where it uses EtherType) and other
2409:
1417:(NIC) before being passed on to the
1378:(FCS) uses a different bit ordering.
302:Physical layer transceiver circuitry
1753:Drew Heywood; Zubair Ahmad (2001).
1273:(the wire bit rate) depends on the
27:Unit of data on an Ethernet network
24:
2069:200, 400, 800 and 1600 Gbit/s
1935:
1905:. New York, NY: IEEE. p. 249.
1215:when 802.1Q VLAN tagging is used.
1199:
1156:
991:
875:datagram, and 0x86DD indicates an
280:Preamble and start frame delimiter
25:
2448:
1434:in the Ethernet LAN architecture.
935:
2408:
2397:
2396:
1963:
1942:
1826:Don Provan (17 September 1993).
1016:v2 protocol suite on Ethernet ("
932:Ethernet_802.2) when using IPX.
689:Interpacket gap – physical layer
275:Ethernet packet – physical layer
1909:
1901:Computer Society, IEEE (2016).
1894:
1861:
1819:
1786:
1771:
1746:
1709:
1669:
1633:
1455:
1446:
1437:
705:Ethernet frame differentiation
1680:Ethernet: The Definitive Guide
1600:
1560:
1424:
1403:
1394:
1381:
1368:
1337:
871:datagram, 0x0806 indicates an
828:
654:Linear Feedback Shift Register
13:
1:
1468:
661:End of frame – physical layer
1803:10.1109/IEEESTD.2018.8457469
1730:10.1109/IEEESTD.2018.8457469
1650:. p. 24. Archived from
1617:10.1109/IEEESTD.2011.6009146
1580:10.1109/IEEESTD.2018.8457469
1544:10.1109/IEEESTD.2018.8457469
1504:10.1109/IEEESTD.2018.8457469
1415:network interface controller
1313:Time spent transmitting data
925:which got confused by this.
780:non-standard variation frame
101:
7:
1793:"3.2.6 Length/Type field".
980:(with the exception of the
146:Start frame delimiter (SFD)
10:
2453:
1917:"Troubleshooting Ethernet"
998:Subnetwork Access Protocol
995:
939:
796:Subnetwork Access Protocol
612:
558:field and, optionally, an
483:for gigabit transceivers)
335:
283:
253:Ethernet packet & IPG
189:Interpacket gap (IPG)
105:
2392:
2346:
2304:
2248:
2177:
2139:
2118:
2077:
2026:
1269:where the physical layer
549:
459:
456:
453:
450:
447:
444:
441:
438:
415:
412:
409:
406:
403:
400:
397:
394:
379:
376:
373:
370:
367:
364:
361:
358:
340:
255:
239:
236:
94:(FCS), which is a 32-bit
2319:SFP/SFP+/QSFP/QSFP+/OSFP
1361:
716:Payload start two bytes
699:
337:56-bit (7-byte) Preamble
245:(not part of the frame)
108:Physical Coding Sublayer
55:and uses the underlying
1530:"3.1.1 Packet format".
1275:Ethernet physical layer
881:EtherType § Values
636:cyclic redundancy check
545:Frame – data link layer
471:for 4-bit wide busses (
237:(not part of the frame)
96:cyclic redundancy check
57:Ethernet physical layer
2064:40 and 100 Gbit/s
1849:HTML-formatted version
1324:
1259:
1206:
1163:
1121:
1076:
891:
634:(FCS) is a four-octet
593:(VLAN) membership and
465:hexadecimal LSb-first
425:for 8-bit wide busses
421:hexadecimal LSb-first
294:and one-octet (8-bit)
37:
2059:25 and 50 Gbit/s
2049:2.5 and 5 Gbit/s
1854:18 April 2015 at the
1684:. O'Reilly. pp.
1325:
1260:
1207:
1164:
1122:
1085:We may calculate the
1077:
1028:We may calculate the
1004:service access points
912:Novell raw IEEE 802.3
889:
856:field in an Ethernet
732:Novell raw IEEE 802.3
296:start frame delimiter
35:
1757:. Sams. p. 53.
1376:frame check sequence
1358:or software issues.
1299:
1229:
1180:
1137:
1096:
1039:
862:upper layer protocol
787:Logical Link Control
632:frame check sequence
626:Frame check sequence
576:frame check sequence
348:uncoded on-the-wire
179:Frame check sequence
92:frame check sequence
1432:collision detection
1304:Channel utilization
1290:channel utilization
1285:Channel utilization
1101:Protocol efficiency
1087:protocol efficiency
834:Ethernet II framing
713:Ethertype or length
706:
329:
261:← 12 octets →
136:
42:computer networking
2019:local area network
1828:"Ethernet Framing"
1320:
1279:Maximum throughput
1255:
1202:
1159:
1117:
1072:
1024:Maximum throughput
892:
823:quality of service
811:quality of service
704:
327:
257:← 72–1530 octets →
241:← 64–1522 octets →
168:) or length (
134:
53:protocol data unit
38:
2424:
2423:
2276:Energy Efficiency
2131:Ethernet Alliance
1974:
1953:
1812:978-1-5044-5090-4
1764:978-0-672-31741-5
1739:978-1-5044-5090-4
1626:978-0-7381-6708-4
1589:978-1-5044-5090-4
1553:978-1-5044-5090-4
1513:978-1-5044-5090-4
1318:
1317:
1314:
1305:
1251:
1243:
1235:
1191:
1148:
1115:
1114:
1111:
1102:
1070:
1069:
1064:
1056:
1045:
1044:Protocol overhead
1030:protocol overhead
974:Internet standard
764:
763:
535:
534:
265:
264:
88:Internet Protocol
74:is preceded by a
16:(Redirected from
2444:
2412:
2411:
2400:
2399:
2008:
2001:
1994:
1985:
1984:
1976:
1975:
1955:
1954:
1929:
1928:
1926:
1924:
1913:
1907:
1906:
1898:
1892:
1891:
1882:
1880:10.17487/RFC1042
1865:
1859:
1846:
1823:
1817:
1816:
1797:. 14 June 2018.
1790:
1784:
1783:
1775:
1769:
1768:
1750:
1744:
1743:
1724:. 14 June 2018.
1713:
1707:
1706:
1704:
1702:
1683:
1673:
1667:
1666:
1664:
1662:
1656:
1645:
1637:
1631:
1630:
1604:
1598:
1597:
1564:
1558:
1557:
1538:. 14 June 2018.
1527:
1518:
1517:
1498:. 14 June 2018.
1488:
1462:
1459:
1453:
1450:
1444:
1441:
1435:
1428:
1422:
1407:
1401:
1398:
1392:
1385:
1379:
1372:
1329:
1327:
1326:
1321:
1319:
1315:
1312:
1311:
1306:
1303:
1264:
1262:
1261:
1256:
1252:
1249:
1244:
1241:
1236:
1233:
1211:
1209:
1208:
1203:
1192:
1184:
1168:
1166:
1165:
1160:
1149:
1141:
1126:
1124:
1123:
1118:
1116:
1112:
1109:
1108:
1103:
1100:
1081:
1079:
1078:
1073:
1071:
1067:
1066:
1065:
1062:
1057:
1054:
1051:
1046:
1043:
972:There exists an
707:
703:
433:Gigabit Ethernet
392:-first ordering
330:
326:
258:
242:
166:Ethernet II
137:
133:
125:Gigabit Ethernet
21:
2452:
2451:
2447:
2446:
2445:
2443:
2442:
2441:
2427:
2426:
2425:
2420:
2388:
2342:
2300:
2244:
2173:
2135:
2114:
2090:Autonegotiation
2073:
2039:100 Mbit/s
2022:
2012:
1980:
1977:
1964:
1959:
1956:
1943:
1938:
1936:Further reading
1933:
1932:
1922:
1920:
1919:. Cisco Systems
1915:
1914:
1910:
1899:
1895:
1867:
1866:
1862:
1856:Wayback Machine
1836:comp.sys.novell
1824:
1820:
1813:
1792:
1791:
1787:
1776:
1772:
1765:
1751:
1747:
1740:
1715:
1714:
1710:
1700:
1698:
1696:
1674:
1670:
1660:
1658:
1657:on 11 June 2020
1654:
1643:
1639:
1638:
1634:
1627:
1606:
1605:
1601:
1590:
1566:
1565:
1561:
1554:
1529:
1528:
1521:
1514:
1490:
1489:
1476:
1471:
1466:
1465:
1460:
1456:
1451:
1447:
1442:
1438:
1429:
1425:
1411:packet sniffing
1408:
1404:
1399:
1395:
1386:
1382:
1373:
1369:
1364:
1356:duplex mismatch
1352:buffer underrun
1340:
1310:
1302:
1300:
1297:
1296:
1248:
1240:
1232:
1230:
1227:
1226:
1183:
1181:
1178:
1177:
1140:
1138:
1135:
1134:
1107:
1099:
1097:
1094:
1093:
1061:
1053:
1052:
1050:
1042:
1040:
1037:
1036:
1026:
1000:
994:
992:IEEE 802.2 SNAP
944:
938:
914:
836:(also known as
831:
754:IEEE 802.2 SNAP
702:
694:Interpacket gap
691:
663:
628:
615:
572:interpacket gap
552:
547:
333:Representation
288:
282:
277:
256:
240:
234:Ethernet frame
170:IEEE 802.3
149:MAC destination
110:
104:
50:data link layer
28:
23:
22:
15:
12:
11:
5:
2450:
2440:
2439:
2422:
2421:
2419:
2418:
2406:
2393:
2390:
2389:
2387:
2386:
2381:
2376:
2371:
2366:
2361:
2356:
2350:
2348:
2344:
2343:
2341:
2340:
2335:
2330:
2321:
2316:
2310:
2308:
2302:
2301:
2299:
2298:
2293:
2288:
2283:
2278:
2273:
2268:
2263:
2258:
2252:
2250:
2246:
2245:
2243:
2242:
2237:
2232:
2227:
2222:
2217:
2212:
2207:
2202:
2197:
2192:
2187:
2181:
2179:
2175:
2174:
2172:
2171:
2170:
2169:
2159:
2154:
2149:
2143:
2141:
2137:
2136:
2134:
2133:
2128:
2122:
2120:
2116:
2115:
2113:
2112:
2107:
2102:
2097:
2092:
2087:
2085:Physical layer
2081:
2079:
2075:
2074:
2072:
2071:
2066:
2061:
2056:
2054:10 Gbit/s
2051:
2046:
2041:
2036:
2034:10 Mbit/s
2030:
2028:
2024:
2023:
2011:
2010:
2003:
1996:
1988:
1982:
1981:
1978:
1962:
1960:
1957:
1941:
1937:
1934:
1931:
1930:
1908:
1893:
1860:
1818:
1811:
1785:
1770:
1763:
1745:
1738:
1708:
1694:
1668:
1632:
1625:
1599:
1588:
1559:
1552:
1519:
1512:
1473:
1472:
1470:
1467:
1464:
1463:
1454:
1445:
1436:
1423:
1402:
1393:
1380:
1366:
1365:
1363:
1360:
1339:
1336:
1331:
1330:
1309:
1288:calculate the
1267:
1266:
1247:
1239:
1213:
1212:
1201:
1198:
1195:
1190:
1187:
1170:
1169:
1158:
1155:
1152:
1147:
1144:
1128:
1127:
1106:
1083:
1082:
1060:
1049:
1025:
1022:
996:Main article:
993:
990:
940:Main article:
937:
936:IEEE 802.2 LLC
934:
929:Novell NetWare
913:
910:
879:datagram. See
840:, named after
830:
827:
800:
799:
790:
781:
771:
762:
761:
758:
755:
751:
750:
747:
744:
743:IEEE 802.2 LLC
740:
739:
736:
733:
729:
728:
725:
722:
718:
717:
714:
711:
701:
698:
690:
687:
667:end of a frame
662:
659:
627:
624:
614:
611:
551:
548:
546:
543:
533:
532:
529:
526:
523:
520:
517:
514:
511:
508:
505:
502:
499:
496:
493:
490:
487:
484:
462:
461:
458:
455:
452:
449:
446:
443:
440:
437:
435:transceivers)
418:
417:
414:
411:
408:
405:
402:
399:
396:
393:
382:
381:
378:
375:
372:
369:
366:
363:
360:
357:
345:
344:
339:
334:
281:
278:
276:
273:
263:
262:
259:
254:
247:
246:
243:
238:
235:
228:
227:
224:
221:
218:
215:
212:
209:
206:
203:
200:
192:
191:
186:
176:
173:
159:
158:tag (optional)
153:
150:
147:
144:
141:
103:
100:
80:physical layer
46:Ethernet frame
26:
18:Ethernet Frame
9:
6:
4:
3:
2:
2449:
2438:
2435:
2434:
2432:
2417:
2416:
2407:
2405:
2404:
2395:
2394:
2391:
2385:
2382:
2380:
2377:
2375:
2372:
2370:
2367:
2365:
2362:
2360:
2357:
2355:
2352:
2351:
2349:
2345:
2339:
2336:
2334:
2331:
2329:
2325:
2322:
2320:
2317:
2315:
2312:
2311:
2309:
2307:
2303:
2297:
2294:
2292:
2289:
2287:
2284:
2282:
2279:
2277:
2274:
2272:
2269:
2267:
2264:
2262:
2259:
2257:
2254:
2253:
2251:
2247:
2241:
2238:
2236:
2233:
2231:
2228:
2226:
2223:
2221:
2218:
2216:
2213:
2211:
2208:
2206:
2203:
2201:
2198:
2196:
2193:
2191:
2188:
2186:
2183:
2182:
2180:
2176:
2168:
2165:
2164:
2163:
2160:
2158:
2155:
2153:
2150:
2148:
2145:
2144:
2142:
2138:
2132:
2129:
2127:
2124:
2123:
2121:
2119:Organizations
2117:
2111:
2108:
2106:
2103:
2101:
2098:
2096:
2093:
2091:
2088:
2086:
2083:
2082:
2080:
2076:
2070:
2067:
2065:
2062:
2060:
2057:
2055:
2052:
2050:
2047:
2045:
2044:1 Gbit/s
2042:
2040:
2037:
2035:
2032:
2031:
2029:
2025:
2020:
2016:
2009:
2004:
2002:
1997:
1995:
1990:
1989:
1986:
1961:
1940:
1939:
1918:
1912:
1904:
1897:
1889:
1886:
1881:
1876:
1872:
1871:
1864:
1857:
1853:
1850:
1844:
1841:
1837:
1833:
1829:
1822:
1814:
1808:
1804:
1800:
1796:
1789:
1781:
1774:
1766:
1760:
1756:
1749:
1741:
1735:
1731:
1727:
1723:
1719:
1712:
1697:
1695:9780596552824
1691:
1687:
1682:
1681:
1672:
1653:
1649:
1642:
1636:
1628:
1622:
1618:
1614:
1610:
1603:
1596:
1591:
1585:
1581:
1577:
1573:
1569:
1563:
1555:
1549:
1545:
1541:
1537:
1533:
1526:
1524:
1515:
1509:
1505:
1501:
1497:
1493:
1487:
1485:
1483:
1481:
1479:
1474:
1458:
1449:
1440:
1433:
1427:
1420:
1416:
1412:
1406:
1397:
1390:
1384:
1377:
1371:
1367:
1359:
1357:
1353:
1349:
1345:
1335:
1307:
1295:
1294:
1293:
1291:
1286:
1282:
1280:
1276:
1272:
1245:
1237:
1225:
1224:
1223:
1221:
1216:
1196:
1193:
1188:
1185:
1176:
1175:
1174:
1153:
1150:
1145:
1142:
1133:
1132:
1131:
1104:
1092:
1091:
1090:
1089:for Ethernet
1088:
1058:
1047:
1035:
1034:
1033:
1031:
1021:
1019:
1015:
1010:
1007:
1005:
999:
989:
987:
983:
979:
975:
970:
968:
964:
960:
956:
951:
949:
943:
933:
930:
926:
924:
919:
909:
905:
902:
897:
888:
884:
882:
878:
874:
870:
866:
863:
859:
855:
851:
847:
843:
839:
835:
826:
824:
818:
816:
812:
807:
805:
797:
794:
791:
788:
785:
782:
779:
775:
772:
769:
768:
767:
759:
756:
753:
752:
748:
745:
742:
741:
737:
734:
731:
730:
726:
723:
720:
719:
715:
712:
709:
708:
697:
695:
686:
684:
680:
679:end of stream
676:
672:
668:
658:
655:
650:
646:
644:
639:
637:
633:
623:
621:
610:
608:
604:
600:
596:
592:
588:
584:
579:
577:
573:
567:
565:
561:
557:
542:
540:
530:
527:
524:
521:
518:
515:
512:
509:
506:
503:
500:
497:
494:
491:
488:
485:
482:
478:
477:Fast Ethernet
474:
470:
469:
464:
463:
436:
434:
430:
424:
420:
419:
391:
387:
384:
383:
355:
351:
347:
346:
343:
338:
332:
331:
325:
323:
319:
315:
311:
307:
303:
299:
297:
293:
287:
272:
270:
260:
252:
249:
248:
244:
233:
230:
229:
225:
222:
219:
216:
213:
210:
207:
204:
201:
198:
194:
193:
190:
187:
184:
180:
177:
174:
171:
167:
163:
160:
157:
154:
151:
148:
145:
142:
139:
138:
132:
130:
126:
122:
117:
115:
109:
99:
97:
93:
89:
85:
84:MAC addresses
81:
77:
73:
68:
66:
62:
58:
54:
51:
47:
43:
34:
30:
19:
2413:
2401:
2306:Transceivers
2249:Applications
2152:Twisted pair
2104:
2100:Flow control
2021:technologies
1921:. Retrieved
1911:
1902:
1896:
1869:
1863:
1821:
1794:
1788:
1779:
1773:
1754:
1748:
1717:
1711:
1699:. Retrieved
1679:
1671:
1659:. Retrieved
1652:the original
1635:
1608:
1602:
1593:
1567:
1562:
1531:
1491:
1457:
1448:
1439:
1426:
1405:
1396:
1388:
1383:
1370:
1348:network card
1341:
1332:
1283:
1271:net bit rate
1268:
1250:Net bit rate
1217:
1214:
1171:
1129:
1110:Payload size
1086:
1084:
1063:Payload size
1027:
1011:
1008:
1003:
1001:
982:5.9 GHz band
971:
952:
945:
927:
915:
906:
893:
865:encapsulated
838:DIX Ethernet
837:
833:
832:
819:
815:IEEE 802.3ac
808:
801:
798:(SNAP) frame
765:
692:
678:
674:
666:
664:
651:
647:
640:
629:
620:jumbo frames
616:
606:
602:
598:
587:IEEE 802.1ad
580:
568:
564:IEEE 802.1ad
553:
536:
467:
426:
422:
388:in Ethernet
385:
349:
341:
336:
300:
295:
289:
269:IEEE 802.1ad
266:
129:jumbo frames
118:
111:
70:An Ethernet
69:
45:
39:
29:
2296:Synchronous
2271:Data center
1607:"Annex G".
1419:OSI layer 2
1338:Runt frames
1113:Packet size
1068:Packet size
1055:Packet size
978:IEEE 802.11
829:Ethernet II
789:(LLC) frame
721:Ethernet II
675:end of data
595:IEEE 802.1p
591:virtual LAN
583:IEEE 802.1Q
560:IEEE 802.1Q
539:MAC address
350:bit pattern
2347:Interfaces
2281:Industrial
2261:Automotive
2240:Long Reach
2162:First mile
2126:IEEE 802.3
2017:family of
1661:30 January
1469:References
1344:collisions
1316:Total time
1242:Efficiency
1234:Throughput
1220:throughput
969:networks.
963:Token Ring
942:IEEE 802.2
901:IEEE 802.2
883:for more.
793:IEEE 802.2
784:IEEE 802.2
778:IEEE 802.3
710:Frame type
643:polynomial
574:and valid
284:See also:
152:MAC source
106:See also:
2235:LattisNet
2230:100BaseVG
2205:10BASE-FL
2200:10BASE-FB
2195:10BROAD36
2095:EtherType
1923:13 August
1832:Newsgroup
1246:×
1200:%
1157:%
1059:−
1018:EtherTalk
1014:AppleTalk
948:OSI stack
854:EtherType
556:EtherType
380:10101011
377:10101010
374:10101010
371:10101010
368:10101010
365:10101010
362:10101010
359:10101010
162:Ethertype
102:Structure
61:data unit
2437:Ethernet
2431:Category
2403:Category
2178:Historic
2167:10G-EPON
2015:Ethernet
1852:Archived
986:IEEE 802
671:10BASE-T
605:rotocol
429:GMII bus
342:SFD byte
292:preamble
286:Syncword
195:Length (
181:(32‑bit
143:Preamble
76:preamble
65:Ethernet
2415:Commons
2266:Carrier
2215:10BASE2
2210:10BASE5
2190:StarLAN
2185:CSMA/CD
2157:Coaxial
2078:General
1840:Usenet:
1834::
1701:30 June
1648:AUTOSAR
955:NetWare
760:0xAAAA
738:0xFFFF
613:Payload
585:tag or
578:(FCS).
562:tag or
473:MII bus
468:nibbles
386:decimal
354:symbols
251:Layer 1
232:Layer 2
220:42–1500
175:Payload
2324:XENPAK
2110:Jumbos
2105:Frames
2027:Speeds
1842:
1809:
1761:
1736:
1692:
1688:, 47.
1623:
1595:first.
1586:
1550:
1510:
923:DECnet
774:Novell
757:≤ 1500
749:Other
746:≤ 1500
735:≤ 1500
724:≥ 1536
683:8b/10b
550:Header
197:octets
156:802.1Q
63:on an
2379:XGMII
2291:Power
2286:Metro
2256:Audio
2225:FOIRL
2147:Fiber
2140:Media
1655:(PDF)
1644:(PDF)
1362:Notes
1197:97.28
1154:97.53
858:frame
850:Xerox
846:Intel
700:Types
566:tag.
481:RGMII
460:0xD5
457:0x55
454:0x55
451:0x55
448:0x55
445:0x55
442:0x55
439:0x55
423:bytes
322:XGMII
318:SGMII
314:RGMII
140:Layer
114:octet
72:frame
48:is a
44:, an
2384:XAUI
2374:GMII
2314:GBIC
1925:2016
1888:1042
1807:ISBN
1759:ISBN
1734:ISBN
1722:IEEE
1703:2014
1690:ISBN
1663:2020
1621:ISBN
1584:ISBN
1572:IEEE
1548:ISBN
1536:IEEE
1508:ISBN
1496:IEEE
1374:The
1218:The
1189:1542
1186:1500
1146:1538
1143:1500
1012:The
967:FDDI
896:IEEE
877:IPv6
869:IPv4
848:and
776:raw
727:Any
665:The
630:The
581:The
531:0xD
528:0x5
525:0x5
522:0x5
519:0x5
516:0x5
513:0x5
510:0x5
507:0x5
504:0x5
501:0x5
498:0x5
495:0x5
492:0x5
489:0x5
486:0x5
475:for
431:for
416:213
310:GMII
2369:MII
2364:MDI
2359:EAD
2354:AUI
2338:CFP
2333:XFP
2220:MAU
1885:RFC
1875:doi
1799:doi
1726:doi
1613:doi
1576:doi
1540:doi
1500:doi
1389:not
965:or
918:IPX
873:ARP
842:DEC
804:MTU
677:or
601:ag
479:or
413:85
410:85
407:85
404:85
401:85
398:85
395:85
390:LSb
306:MII
226:12
214:(4)
183:CRC
121:MTU
40:In
2433::
2328:X2
1883:.
1838:.
1830:.
1805:.
1732:.
1720:.
1686:41
1646:.
1619:.
1611:.
1592:.
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1570:.
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1522:^
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1350:,
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320:,
316:,
312:,
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1927:.
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1556:.
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1502::
1308:=
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1238:=
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1151:=
1105:=
1048:=
603:P
599:T
427:(
223:4
217:2
211:6
208:6
205:1
202:7
185:)
172:)
164:(
20:)
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