SNMPTRAPD(8) Net-SNMP SNMPTRAPD(8)
snmptrapd - Receive and log SNMP trap messages.
snmptrapd [OPTIONS] [LISTENING ADDRESSES]
snmptrapd is an SNMP application that receives and logs SNMP TRAP and
Note: the default is to listen on UDP port 162 on all IPv4 interfaces.
Since 162 is a privileged port, snmptrapd must be typically be run as
-a Ignore authenticationFailure traps.
-c FILE Read FILE as a configuration file.
-C Do not read any configuration files except the one optionally
specified by the -c option.
-d Dump (in hexadecimal) the sent and received SNMP packets.
Turn on debugging output for the given TOKEN(s). Try ALL for
extremely verbose output.
-e Print event numbers (rising/falling alarm etc.).
-f Do not fork() from the calling shell.
When logging to standard output, use the format in the string
FORMAT. See the section FORMAT SPECIFICATIONS below for more
Display a brief usage message and then exit.
-H Display a list of configuration file directives understood by
the trap daemon and then exit.
Specifies the syslog facility to use when logging to syslog.
'd' means LOG_DAEMON and 0 through 7 mean LOG_LOCAL0 through
LOG_LOCAL7. LOG_LOCAL0 is the default.
Specifies a colon separated list of MIB modules to load for
this application. This overrides the environment variable
Specifies a colon separated list of directories to search for
MIBs. This overrides the environment variable MIBDIRS.
-n Do not attempt to translate source addresses of incoming pack-
ets into hostnames.
-o FILE Log formatted incoming traps to FILE. Upon receipt of a
SIGHUP, the daemon will close and re-open the log file. This
feature is useful when rotating the log file with other utili-
ties such as logrotate.
-P Print formatted incoming traps to stderr.
-s Log formatted incoming traps to syslog. These syslog messages
are sent with a level of LOG_WARNING and facility as determined
by the -l flag (LOG_LOCAL0 by default). This is the default
unless the -o or -P flag is used.
-u FILE Save the process ID of the trap daemon in FILE.
Print version information for the trap daemon and then exit.
In addition, snmptrapd takes the same output formatting (-O) options as
the other Net-SNMP commands. See the section OUTPUT OPTIONS in the
snmpcmd(1) manual page.
snmptrapd interprets format strings similarly to printf(3). It under-
stands the following formatting sequences:
%% a literal %
%t decimal number of seconds since the operating system's epoch
(as returned by time(2))
%y current year on the local system
%m current (numeric) month on the local system
%l current day of month on the local system
%h current hour on the local system
%j current minute on the local system
%k current second on the local system
%T the value of the sysUpTime.0 varbind in seconds
%Y the year field from the sysUpTime.0 varbind
%M the numeric month field from the sysUpTime.0 varbind
%L the day of month field from the sysUpTime.0 varbind
%H the hour field from the sysUpTime.0 varbind
%J the minute field from the sysUpTime.0 varbind
%K the seconds field from the sysUpTime.0 varbind
%a the contents of the agent-addr field of the PDU (v1 TRAPs only)
%A 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).
%b PDU source address (Note: this is not necessarily an IPv4
%B PDU source hostname if available, otherwise PDU source address
(see note above)
%N enterprise string
%w trap type (numeric, in decimal)
%W trap description
%q trap sub-type (numeric, in decimal)
%P security information from the PDU (community name for v1/v2c,
user and context for v3)
%v list of trap's variable-bindings
In addition to these values, you may also specify an optional field
width and precision, just as in printf(3), and a flag value. The fol-
lowing flags are legal:
- left justify
0 use leading zeros
# use alternate form
The "use alternate form" flag changes the behavior of some format
flags. Normally, the fields that display time information base it on
the local timezone, but this flag tells them to use GMT instead. Also,
the variable-binding list is normally a tab-separated list, but this
flag changes it to a comma-separated one. The alternate form for the
uptime is similar to "3 days, 0:14:34.65"
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"
By default, snmptrapd 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 snmptrapd. See the snmpd(8) manual page for more informa-
tion about the format of listening addresses.
As of net-snmp 5.0, the snmptrapd application supports the NOTIFICA-
TION-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 notifica-
tions 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
EXTENSIBILITY AND CONFIGURATION
See the snmptrapd.conf(5) manual page.
snmpcmd(1), snmpd(8), printf(3), snmptrapd.conf(5), syslog(8), vari-
4th Berkeley Distribution 07 Feb 2002 SNMPTRAPD(8)