Yesterday a port on one of my Cisco Catalyst switches had been shutdown due to a security violation. When I check the port I found that the last mac address to try to use the port was 49-34-46-30-37-34. This is not a registered OUI vendor address. Does anyone recognize this address. I thought it might be a Psuedo Mac used by a PPP connection but I believe that Microsoft uses mac addresses starting with 44 for that.