On Fri, Jan 25, 2008 at 10:39:29AM -0800, Steve Feldman wrote: > I don't think that's enough to tell. > > We once got a batch of SFPs which seemed to work just fine, until > we plugged more than one into the same router. It turned out they > had identical serial numbers....
Cisco branded optics use a one-way cryptographic hash of the serial number plus some kind of secret key written to the EEPROM, as a method to prevent people from just easily setting "CISCO-REALVENDOR" on the vendor field to produce clones. The first generation of cloners just copied the serial number and hash from a real Cisco optic, leading Cisco to implement a check for multiple copies of the same serial number in the box. I don't know if the secret key has been compromised, or if the cloners just have access to a really large sample set, but these days they seem to have no problem defeating the check and producing Cisco-branded optics which work in any system. Many optic vendors will even give you a choice of what you want your EEPROM vendor field to say, so you can even make your own "store brand" line of optics the same way that Cisco does. -- Richard A Steenbergen <[EMAIL PROTECTED]> http://www.e-gerbil.net/ras GPG Key ID: 0xF8B12CBC (7535 7F59 8204 ED1F CC1C 53AF 4C41 5ECA F8B1 2CBC) _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
