Ethernet Codes master page

These pages contain collected information on the various codes used on IEEE 802.3 and Ethernet. There are three "pages" of data: These same codes are also used on some other IEEE 802 networks (e.g. 802.5 is Token Ring), but may be in slightly different form. Specifically 802.5 sends the bits of a byte in the opposite order to Ethernet or 802.3, so the codes listed below may have the bits of each byte reversed (e.g. exchange 01/80, 10/08, 0C/30, etc.), although some monitors may undo the reversal back to the Ethernet order. Be careful using this reference for other IEEE 802 media. There is also this page of general info and a page of acknowledgments. I wish to thank the contributors, many are listed on the acknowledgments page and there are almost certainly others that I have missed. There is also a list of other sources of Ethernet info.

Note that these pages are reports of codes seen "in the field" and are thus subject to errors of observation, and are certainly incomplete. They also report the actual vendor of the equipment rather than the original assignment of the code. The IEEE site has their info which is different. Whenever a question arises, I suggest consulting both lists for useful information.

If you are reading this from a stored copy, you may want to get a more up-to-date copy on the net, or you may want to just bookmark the pointer for future reference. The three main URLs for the document are:

Mirrors are available. Located at: If you are interested in being an additional mirror site, please send mail to the address above, include any relevant info, we'll get back to you eventually...

Since this information is from collected wisdom, there are certainly omissions. I welcome any further additions which can be sent to I appreciate it if submissions include a preformatted line for the acknowledgments section (mostly because I have trouble figuring out what abbreviations will be acceptable when names are too long), and to format lines as they are here in the main listings. Use 8 character tab spacing to match the master files. These will ease my use of cut-and-paste to update the list with less effort.

The data on these pages was collected by Michael A. Patton, Internet Consultant, from contributions by the Internet community. Only a globally connected information community can produce collected wisdom like this list, and therefore, in addition to the specific contributors to the list, all those who make the Internet what it is are part of what made this list possible.

Revision info

The following revision info indicates when this page was last updated. Each page has it's own revision date. The best place to look for an overall revision date is the combined text file.
$Revision: 2.18 $
$Date: 1998/10/26 23:54:17 $
$Author: map $
$Id: index.html,v 2.18 1998/10/26 23:54:17 map Exp $