is an SNMP application that receives and logs SNMP TRAP and INFORM
Note: the default is to listen on UDP port 162 on all IPv4 interfaces.
Since 162 is a privileged port,
must typically be run as root.
Ignore authenticationFailure traps.
Append to the log file rather than truncating it.
Note that this needs to come before any -Lf options
that it should apply to.
as a configuration file.
Do not read any configuration files except the one optionally specified by the
Dump (in hexadecimal) the sent and received SNMP packets.
Turn on debugging output for the given
for extremely verbose output.
Print event numbers (rising/falling alarm etc.) from the (obsolete) M2M-MIB.
This functionality is being deprecated and will be removed in due course.
Do not fork() from the calling shell.
When logging to standard output, use the format in the string
See the section
below for more details.
Display a brief usage message and then exit.
Display a list of configuration file directives understood by the
trap daemon and then exit.
Specifies which modules should (or should not) be initialized
when snmptrapd starts up. If the comma-separated
with a '-', it is the list of modules that should not be started.
Otherwise this is the list of the only modules that should be started.
To get a list of compiled modules, run snmptrapd with the arguments
(assuming debugging support has been compiled in).
Specify where logging output should be directed (standard error or output,
to a file or via syslog). See LOGGING OPTIONS in snmpcmd(1) for details.
Specifies a colon separated list of MIB modules to load for this
application. This overrides the environment variable MIBS.
See snmpcmd(1) for details.
Specifies a colon separated list of directories to search for MIBs.
This overrides the environment variable MIBDIRS.
See snmpcmd(1) for details.
Do not attempt to translate source addresses of incoming packets into
Save the process ID of the trap daemon in
Specifies how MIB objects and other output should be displayed.
See the section
manual page for details.
Do not log traps to syslog. This disables logging to syslog. This is
useful if you want the snmptrapd application to
run traphandle hooks and not to log any traps to any location.
Print version information for the trap daemon and then exit.
Connect to the AgentX master agent on the specified address,
rather than the default "/var/agentx/master".
See snmpd(8) for details of the format of such addresses.
Allows to specify any token ("name") supported in the
file and sets its value to "value". Overrides the corresponding token in the
for the full list of tokens.
interprets format strings similarly to
It understands the following formatting sequences:
a literal %
the contents of the agent-addr field of the PDU (v1 TRAPs only)
the hostname corresponding to the contents of the agent-addr field of
the PDU, if available, otherwise the contents of the agent-addr field
of the PDU (v1 TRAPs only).
PDU source address (Note: this is not necessarily an IPv4
PDU source hostname if available, otherwise PDU source address (see
current hour on the local system
the hour field from the sysUpTime.0 varbind
current minute on the local system
the minute field from the sysUpTime.0 varbind
current second on the local system
the seconds field from the sysUpTime.0 varbind
current day of month on the local system
the day of month field from the sysUpTime.0 varbind
current (numeric) month on the local system
the numeric month field from the sysUpTime.0 varbind
trap sub-type (numeric, in decimal)
security information from the PDU (community name for v1/v2c,
user and context for v3)
decimal number of seconds since the operating system epoch (as
the value of the sysUpTime.0 varbind in seconds
list of variable-bindings from the notification payload.
These will be separated by a tab,
or by a comma and a blank if the alternate form is requested
See also %V
specifies the variable-bindings separator. This takes a sequence of
characters, up to the next % (to embed a % in the string, use \%)
trap type (numeric, in decimal)
current year on the local system
the year field from the sysUpTime.0 varbind
In addition to these values, an optional field
width and precision may also be specified , just as in
and a flag value. The following flags are supported:
use leading zeros
use alternate form
The "use alternate form" flag changes the behavior of various format
Time information will be displayed based on GMT (rather than the local timezone)
The variable-bindings will be a comma-separated list (rather than a tab-separated one)
The system uptime will be broken down into a human-meaningful format (rather than being a simple integer)
To get a message like "14:03 TRAP3.1 from humpty.ucd.edu" you
could use something like this:
snmptrapd -P -F "%02.2h:%02.2j TRAP%w.%q from %A\n"
If you want the same thing but in GMT rather than local time, use
snmptrapd -P -F "%#02.2h:%#02.2j TRAP%w.%q from %A\n"
listens for incoming SNMP TRAP and INFORM packets on UDP port 162 on
all IPv4 interfaces. However, it is possible to modify this behaviour
by specifying one or more listening addresses as arguments to
manual page for more information about the format of listening
As of net-snmp 5.0, the snmptrapd application supports the
NOTIFICATION-LOG-MIB. It does this by opening an AgentX subagent
connection to the master snmpd agent and registering the notification
log tables. As long as the snmpd application is started first, it
will attach itself to it and thus you should be able to view the last
recorded notifications via the nlmLogTable and nlmLogVariableTable.
See the snmptrapd.conf file and the "dontRetainLogs" token for turning
off this support. See the NOTIFICATION-LOG-MIB for more details about
the MIB itself.