Charles Spurgeon's Ethernet (IEEE 802.3) Site


Ethernet Resources

Ethernet Numbers:

Ethernet numbers include the 48-bit media access control (MAC) address assigned to each Ethernet interface, and the 16-bit value used in the Type field of the Ethernet frame.
MAC Addresses
Each Ethernet interface is assigned a unique MAC address at the time of manufacture. The first 24 bits of the MAC address consist of an Organizationally Unique Identifier (OUI) assigned to a vendor by the IEEE, which is why they are also called vendor codes. The Ethernet vendor combines their 24-bit OUI with a unique 24-bit value that they generate to create a unique 48-bit address for each Ethernet interface they build.
Type Codes
An Ethernet Type code is a 16-bit number carried in the Type field of the Ethernet frame. This number is used to identify the type of high-level network protocol packet that is being carried in the data field of the Ethernet frame.

Troubleshooting with Ethernet Numbers

OUI (vendor) codes and Type codes can help identify and track down machines and protocols in use on the network. For example, the OUI codes can help identify the vendor of a given Ethernet card that may be sending incorrect traffic. Knowing the vendor can often help you find out which machine on your network may be the one causing problems.

Search the IEEE Organizationally Unique Identifiers (OUIs). This IEEE page provides search access to their list of OUIs and also provides download access to the entire IEEE OUI list. Note that the IEEE list of OUIs is not complete, since vendors can request not to be publically listed. This page also describes how to apply for an OUI of your very own, which costs US $1,250 as of this writing.

IEEE tutorial on Organizationally Unique Identifiers (OUIs). This brief IEEE tutorial describes the use of OUIs in LANs and MANs.

IEEE Type Field page. This IEEE page provides a public list of Type field assignments and the organizations which requested them. This list only identifies the organizations who have requested a Type field for use in their work on protocol development. Michael Patton's list should be consulted for the actual Type identifier used for a given protocol.

Wikipedia: MAC address

Ethernet numbers from IANA. Maintained by the Internet Assigned Numbers Authority (IANA), this list includes assigned multicast addresses.

IEEE LSAP List List of Link Service Access Point (LSAP) numbers assigned by the IEEE. LSAP numbers are used when sending 802.2 logical link control (LLC) data in 802.3 frames with a frame Length field instead of an Ethernet Type field. The 802.2 LLC scheme uses Service Access Point identifiers instead of Type fields to identify the type of data being carried over the network.

IANA list of LSAPs

TheCisco LSAP List

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