Generating actions based on OID status
From Internetworkpro
Well, rmon was developed for such purposes. But rmon cannot track every OID, generate subsequent alarms or pay attention to other conditions you want to include for such alarms.
For such scenarios, the IOS embedded event manager (EEM) comes to the rescue.
I explain this on an alering scenario for IP SLA probes, which do not have log message capability.
First define your probe:
rtr 1 type echo protocol ipIcmpEcho 10.1.3.1 frequency 30
This probe will send ICMP echo requests every 30 seconds to the host 10.1.3.1
Then create an event manager applet
event manager applet rtr_probe_fail event snmp oid 1.3.6.1.4.1.9.9.42.1.2.9.1.6.1 get-type exact entry-op eq entry-val 1 exit-op eq exit-val 2 poll-interval 5 action 1.0 syslog priority critical msg "RTR probe failed"
This tells the event managet to query the Timeout property OID within the RTT definition. The event manager will poll the OID every 5 seconds. If a timeout happened, a syslog message is generated.
http://tools.cisco.com/Support/SNMP/do/BrowseOID.do?local=en