So, you might be correct, but only in the future? John Willkie -----Original Message----- From: opendtv-bounce@xxxxxxxxxxxxx [mailto:opendtv-bounce@xxxxxxxxxxxxx]On Behalf Of Craig Birkmaier Sent: Tuesday, May 04, 2004 11:58 AM To: opendtv@xxxxxxxxxxxxx Subject: [opendtv] Re: Twang's Tuesday Tribune (Mark's Monday Memo) At 10:22 AM -0700 5/4/04, Kon Wilms wrote: > >I can understand how this could happen because of poor control of >addresses by a manufacturer. What I cannot understand is how two >devices located anywhere in the world can share the same MAC address. > >Actually it is quite easy. Of the 6 bytes in a mac address, the first 3 >represent the manufacturer id. The manufacturer must randomize the last 3 >for device rollout. With a range of 3 bytes, there is bound to be >duplication (you can't even roll out a decent amount of receivers without >using up every number). Many manufacturers cut corners in manufacturing and >use a random number generator but do not check against a known list of ids >previously created. > >Plus, you can change the MAC address on most boards (datacast receivers are >notorious for allowing you to do this). > >So its not so useful for targeting or ensuring data only reaches one recipient. Thanks! Doesn't IPV6 deal with these shortcomings? Regards Craig ---------------------------------------------------------------------- You can UNSUBSCRIBE from the OpenDTV list in two ways: - Using the UNSUBSCRIBE command in your user configuration settings at FreeLists.org - By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word unsubscribe in the subject line.