SNMP daemon configuration

The Simple Network Management Protocol (SNMP) daemon is a background server process that can be run on any Transmission Control Protocol/Internet Protocol (TCP/IP) workstation host.

The daemon, acting as SNMP agent, receives, authenticates, and processes SNMP requests from manager applications. See Simple Network Management Protocol, How a Manager Functions, and How an Agent Functions in Communications Programming Concepts for more detailed information on agent and manager functions.

Note: The terms SNMP daemon, SNMP agent, and agent are used interchangeably.

The snmpd daemon requires the loopback TCP/IP interface to be active for minimal configuration. Enter the following command before starting TCP/IP:

ifconfig lo0 loopback up

The SNMP daemon will attempt to bind sockets to certain well-known User Datagram Protocol (UDP) and Transmission Control Protocol (TCP) ports, which must be defined in the /etc/services file as follows:

snmp            161/udp
snmp-trap       162/udp
smux            199/tcp

The snmp service must be assigned port 161, as required by RFC 1157. The /etc/services file assigns ports 161, 162, and 199 to these services. If the /etc/services file is being serviced off another machine, these assigned ports must be made available in the served /etc/services file on the server before the SNMP daemon can run.

The SNMP daemon reads the configuration file on the running SNMP version on startup and when a refresh command (if the snmpd daemon is invoked under System Resource Controller control) or kill -1 signal is issued.