When a trap arrives in the IP Manager, the built-in trap receiver checks for a valid source device address, where a source device address is the IPv4 or IPv6 address of the SNMP agent that is sending the trap message.
To check for a valid source device, the trap receiver examines the following fields in the trap message in the order given:
agent-addr parameter (SNMPv1 trap only)
snmpTrapAddress.0 variable-binding (if available) (SNMP v2c trap only)
smSnmpTrapInetAddressType variable-binding (if available)
smSnmpTrapInetAddress variable-binding (if available)
“Examples of forwarding entries” on page 100 lists available forwarding entries for the IP Managers in the trapd.conf file.
After reading the source device address and the community string in the header of the SNMP message, to determine the source of the information that is contained in the trap message, the trap receiver parses the variable-bindings in the trap message to extract one or more data values that give information about the source device’s state.