Roger, So I assume if you purchase an OUI you get a block of 2^24 = 16M addresses OR you can purchase a minimum block of 4,096 addresses but you don't get an OUI?
John ________________________________________ John Kennedy Idaho Technology Inc. 390 Wakara Way Salt Lake City, UT 84108, USA USA: 1-800-735-6544 Bus:+1 (801)736-6354 x448 Fax:+1 (801)588-0507 http://www.idahotech.com/ -----Original Message----- From: Roger Cover [mailto:[email protected]] Sent: Friday, April 10, 2009 11:12 AM To: Mailing list for lwIP users Subject: RE: [lwip-users] MAC Address? Howdy Folks, Here is a bit of information about MAC addresses that might be applicable to this discussion: MAC addresses can either be "universally administered" or "locally administered." A universally administered address is assigned to a device by its manufacturer. The first three octets are the Organizationally Unique Identifier (OUI) of the manufacturer (issued by the IEEE). The remaining octets are assigned by the manufacturer. A locally administered address can be assigned to a device by any network administrator. Locally administered addresses must not contain OUIs. Universally administered and locally administered addresses are identifiable by the bit who's value is 2 in the most significant byte of the address. A zero in that bit indicates a universally administered address. A one indicates a locally administered address. For example: 02-12-34-56-78-90 is a locally administered address, 00-1B-21-11-74-58 is the address of my NIC (00-1B-21 is Intel's OUI). The IEEE will not issue an OUI with this bit set. Locally administered addresses are the responsibility of the network administrator where they are used. Universally administered address are the responsibility of device manufacturers. >>> Are there some pre-allocated MAC addresses one can use temporarily >>> for testing? If you want a MAC address for testing a product under development, you can just pick any locally administered address you want (subject to your network administrator's guidance). If you want a MAC address for shipping a product, you need to buy a block of addresses or buy a company OUI. Both of them are reasonably inexpensive and can be used for any number of products. Regards, Roger _______________________________________________ lwip-users mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/lwip-users ________________________________________ CONFIDENTIALITY NOTICE: This E-mail and any attachments are confidential information of the sender and are for the exclusive use of the intended recipient. If you are not the intended recipient, be aware that any disclosure, copying, distribution, or use of this E-mail or any attachment is prohibited. If you have received this E-mail in error, please notify us immediately by returning it to the sender and delete this copy from your system. Thank you for your cooperation. _______________________________________________ lwip-users mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/lwip-users
