Fiz um script para rodar no CISCO serie 3000 e serie 9000, monitorando CDP nas interfaces com link lan to lan, identificando uma interface down fará disable da interface.

event manager applet monitor_cdp
 event syslog pattern "CDP-4-NOTIF.*CDP neighbor.*port_id"
 action 1.0 cli command "enable"
 action 2.0 cli command "show cdp neighbors"
 action 3.0 regexp "(GigabitEthernet(?:8|11|12))" "$_cli_result" match intf_list
 action 4.0 foreach intf $intf_list
 action 5.0   cli command "show cdp neighbors interface $intf"
 action 6.0   regexp "^(.*?)(?:$intf)(?:.*?)([A-Za-z]+[0-9]+(?:/[0-9]+)?) " "$_cli_result" match neighbor_intf
 action 7.0   if "$neighbor_intf eq \"\""  
 action 8.0     cli command "conf t"
 action 9.0     cli command "interface $intf"
 action 10.0    cli command "shutdown"
 action 11.0    syslog msg "Interface $intf was shut down due to CDP neighbor loss"
 action 12.0  end
 action 13.0 end