Template:FAQ:Agent 16
The agent sends a 'coldStart(0)' trap when it first starts up, and an
enterprise-specific trap 'nsNotifyShutdown' (or 'ucdShutdown') when it
stops. It can also be configured to send an 'authenticationFailure(4)'
trap when it receives an SNMPv1 request using an unknown community name.
The Net-SNMP agent generates an enterprise-specific trap 'nsNotifyRestart'
(rather than the standard 'coldStart(0)' or 'warmStart(1)' traps) on
receiving a HUP signal - typically after being re-configured.
The agent does not send 'linkUp' or 'linkDown' traps by default. It can be configured to do this using the directive 'linkUpDownNotifications'.
See the 'snmpd.conf(5)' man page (under ACTIVE MONITORING)
for details.
Similarly, it does not generate traps by default when one of the
monitored characteristics (disk usage, running processes, etc) enters or
leaves an error state. This can be configured using the 'defaultMonitors'
directive (again documented under ACTIVE MONITORING).
Note that these facilities are only available with the v5 Net-SNMP agent, and are not supported by the v4 UCD agent.
