Assume that we have an AR and it is monitored by eSight Network. At a certain moment inteface for LAN is going down but on eSight we do not receive any alarm. Below you have the topology.
We can see that in eSight, AR is configured based on Loopback 10 and in this tipology we should receive a SNMP trap from AR.
If we check the configuration on AR we will see that the fallowing command is configured: snmp-agen trap source interface G0/0/1. This is the reason why we do not receive any trap from AR. It is recommended to set the source for trap a Loopback, the same Loopback that it is monitored by the eSight, in our case Loopback 10.
After we change the configuration to snmp-agent trap source Loopback10 , we will see that if interface goes down SNMP trap will be sent by AR and an alarm will be generated in eSight.