Finne dataen i ethernet headeren.

[Techster]

Jeg skriver et lite nettverk program i C# og støtt på et problem.

Så vidt jeg vet så skal ethernet headeren vært 14 bytes lang og og inneholde avsenders mac(byte 0-5), mottakers mac(byte 6-11) samt type koden(byte 12-13)

 

Jeg sniffer alle pakkene på nettverket, leser inn de 14(0-13) første bytene men finner ikke en eneste mac adresse som stemmer med de på nettverket.

 

Noen som forstår seg på dette?

[x871kx6167ss7]

Fra wikipedia om MAC-adresser. Kanskje det er grunnen?

 

The standard transmission order notation for MAC addresses, as seen in the output of the ifconfig/ipconfig command for example, is also called canonical format.

 

However, since IEEE 802.3 (Ethernet) and IEEE 802.4 (Token Bus) send the bits over the wire with least significant bit first, while IEEE 802.5 (Token Ring) and IEEE 802.6 send the bits over the wire with most significant bit first, confusion may arise where an address in the latter scenario is represented with bits reversed from the canonical representation. So for instance, an address whose canonical form is 12-34-56-78-9A-BC would be transmitted over the wire as bits 01001000 00101100 01101010 00011110 01011001 00111101 in the standard transmission order (least significant bit first). But for Token Ring networks, it would be transmitted as bits 00010010 00110100 01010110 01111000 10011010 10111100 in most significant bit first order. If care is not taken to translate correctly and consistently to the canonical representation, the latter might be displayed as 482C6A1E593D, which could cause confusion. This would be referred to as "Bit-reversed order", "Non-canonical form", "MSB format", "IBM format", or "Token Ring format" as explained by RFC 2469. Canonical form is preferred, generally because the more modern implementations do not use non-canonical form.