cisco snmp trap::

SNMP community:
snmp-server community public RO

SNMP trap community ( trap-group ):
snmp-server host 192.168.0.224 version 2c proba_group

Enable traps, you want to receive form the device:
snmp-server trap link ietf
snmp-server enable traps snmp authentication linkdown linkup coldstart warmstart
snmp-server enable traps ospf state-change
snmp-server enable traps ospf errors
snmp-server enable traps ospf retransmit
snmp-server enable traps ospf lsa
snmp-server enable traps ospf cisco-specific state-change nssa-trans-change
snmp-server enable traps ospf cisco-specific state-change shamlink interface-old
snmp-server enable traps ospf cisco-specific state-change shamlink neighbor
snmp-server enable traps ospf cisco-specific errors
snmp-server enable traps ospf cisco-specific retransmit
snmp-server enable traps ospf cisco-specific lsa