snmptrapd - Receive and log SNMP trap messages.
snmptrapd [OPTIONS] [LISTENING ADDRESSES]
snmptrapd is an SNMP application that receives and logs
SNMP TRAP and INFORM messages.
Note: the default is to listen on UDP port 162 on all IPv4
interfaces. Since 162 is a privileged port, snmptrapd must typically
be run as root.
- -a
- Ignore authenticationFailure traps.
- -A
- Append to the log file rather than truncating it.
Note that this needs to come before any -Lf options
that it should apply to.
- -c FILE
- Read FILE as a configuration file (or a comma-separated list of
configuration files).
- -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.
- -D[TOKEN[,...]]
- Turn on debugging output for the given TOKEN(s). Try ALL for
extremely verbose output.
- -f
- Do not fork() from the calling shell.
- -F FORMAT
- When logging to standard output, use the format in the string
FORMAT. See the section FORMAT SPECIFICATIONS below for more
details.
- -h, --help
- Display a brief usage message and then exit.
- -H
- Display a list of configuration file directives understood by the trap
daemon and then exit.
- -I
[-]INITLIST
- Specifies which modules should (or should not) be initialized when
snmptrapd starts up. If the comma-separated INITLIST is preceded
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 -Dmib_init -H (assuming debugging support has been
compiled in).
- -L[efos]
- 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.
- -m MIBLIST
- Specifies a colon separated list of MIB modules to load for this
application. This overrides the environment variable MIBS. See
snmpcmd(1) for details.
- -M DIRLIST
- Specifies a colon separated list of directories to search for MIBs. This
overrides the environment variable MIBDIRS. See snmpcmd(1) for
details.
- -n
- Do not attempt to translate source addresses of incoming packets into
hostnames.
- -p FILE
- Save the process ID of the trap daemon in FILE.
- -O
[abeEfnqQsStTuUvxX]
- Specifies how MIB objects and other output should be displayed. See the
section OUTPUT OPTIONS in the snmpcmd(1) manual page for
details.
- -t
- Do not log traps to syslog. This disables logging to syslog. This is
useful if you want the snmptrapd application to only run traphandle
hooks and not to log any traps to any location.
- -v, --version
- Print version information for the trap daemon and then exit.
- -x ADDRESS
- Connect to the AgentX master agent on the specified address, rather than
the default AGENTX_SOCKET. See snmpd(8) for details of the format
of such addresses.
- --name="value"
- Allows to specify any token ("name") supported in the
snmptrapd.conf file and sets its value to "value".
Overrides the corresponding token in the snmptrapd.conf file. See
snmptrapd.conf(5) for the full list of tokens.
snmptrapd interprets format strings similarly to
printf(3). It understands the following formatting sequences:
- %%
- a literal %
- %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 address)
- %B
- PDU source hostname if available, otherwise PDU source address (see note
above)
- %h
- current hour on the local system
- %H
- the hour field from the sysUpTime.0 varbind
- %j
- current minute on the local system
- %J
- the minute field from the sysUpTime.0 varbind
- %k
- current second on the local system
- %K
- the seconds field from the sysUpTime.0 varbind
- %l
- current day of month on the local system
- %L
- the day of month field from the sysUpTime.0 varbind
- %m
- current (numeric) month on the local system
- %M
- the numeric month field from the sysUpTime.0 varbind
- %N
- enterprise string
- %q
- trap sub-type (numeric, in decimal)
- %P
- security information from the PDU (community name for v1/v2c, user and
context for v3)
- %t
- decimal number of seconds since the operating system epoch (as returned by
time(2))
- %T
- the value of the sysUpTime.0 varbind in seconds
- %v
- 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
- %V
- specifies the variable-bindings separator. This takes a sequence of
characters, up to the next % (to embed a % in the string, use \%)
- %w
- trap type (numeric, in decimal)
- %W
- trap description
- %y
- current year on the local system
- %Y
- 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 printf(3), and a flag value. The
following flags are supported:
- -
- left justify
- 0
- use leading zeros
- #
- use alternate form
The "use alternate form" flag changes the behavior of
various format string sequences:
- 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"
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 information about the format of listening addresses.
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
"doNotRetainNotificationLogs" token for turning off this support.
See the NOTIFICATION-LOG-MIB for more details about the MIB itself.
See the snmptrapd.conf(5) manual page.
snmpcmd(1), snmpd(8), printf(3), snmptrapd.conf(5), syslog(8),
variables(5)