Template:FAQ:Applications 17c
From Net-SNMP Wiki
Starting with net-snmp 5.3, snmptrapd will no longer automatically accept all incoming traps. It must be configured with authorized SNMPv1/v2c community strings and/or SNMPv3 users. Non-authorized traps/informs will be dropped.
Please refer to the snmptrapd.conf(5) manual page for details.