EEM applets

Embedded Event Manager

General information on “EEM applets”:

• Used to automate tasks based on events happening on the network device
• EEM components:
  • EEM server: Consists of event detectors/publishers and event subscribers. Triggers a subscriber when a detector/publisher sends a notification about an interesting event (defined by the event subscribers).
  • Event detectors/publishers: Monitoring the device for events happening (defined by the event subscribers) and notify the EEM server in case of an interesting event.
  • Event subscribers: Scripts that get triggered through the EEM server by an event that happened at one of the event detectors/publishers.
• Possible detectors/publishers:
  • Interface: Allows interface parameters to be monitored (eg. threshold violation).
  • Routing: Allows routing events to be monitored (eg. routes)
  • SNMP: Allows MIB objects to be monitored.
  • Syslog: Allows syslogs to be monitored for a specific pattern/string.
  • Timer: Allows actions to be executed based on a specific time (eg. cron job).
  • Track: Allows tracking objects to be monitored (eg. up/down state).
  • […]
• Global variables can be defined to use within all applets
• Actions are executed in lexicographical order (= dictionary order) therefor it’s common to use action 1.0 … action 2.0 … and so on
• Important: EEM starts at the initial USER EXEC mode, therefore the first command should be “enable”!

“EEM applets” configuration steps:

1. Define global EEM variables (if needed)
2. Create (register) an EEM applet (policy)
3. Set event to monitor
4. Set action to take in case the monitored event happens

“EEM applets” CLI configuration commands:

## Defining a global EEM variable
Router(config)# event manager environment <name> <value>

## Creating an EEM applet
Router(config)# event manager applet [NAME]

## Setting an event to monitor
Router(config-applet)# event <type> [arguments]

## Setting actions to take
Router(config-applet)# action <number> <type> [arguments]

“EEM applets” example:

Router(config)# track 111 interface Loopback111 line-protocol

Router(config)# event manager applet INTERFACE_TRACKER
Router(config-applet)# event track 111 state down
Router(config-applet)# action 1.0 syslog msg "Interface Lo111 down - EEM will fix this!!!"
Router(config-applet)# action 1.5 wait 2
Router(config-applet)# action 2.0 cli command "enable"
Router(config-applet)# action 2.1 cli command "configure terminal"
Router(config-applet)# action 2.2 cli command "interface lo1111"
Router(config-applet)# action 2.3 cli command "no shutdown"
Router(config-applet)# action 3.0 syslog msg "Interface Lo111 up - Fixed by EEM!!!"