hi john
you make create port security enable on your 2650 switch related ports.
(config)#port-security[port-list]learn-mode [static-continius] address-limit[1-32]action[send-disable/send-alarm]
port-security :main command
port-list ethernet ports on run port security
learn-mode :learning mode switch each device learning mac address auto. and after write on port.
static mode:switch power loss or restart port security mac information not loss on switch
continius:switch power loss or resatart port security mac information loss on switch
address limit :one port assign maxima 32 mac address
action :send disable :occur port-securiy intrusion on port ,port is disable
send alarm:port-security intrusion on port
send alarm procurve manager and switch security intrution logging and port closed ,snmp,icm etc. portocol trafic.
cenk