Provided by: snmptrapd_5.9.4+dfsg-1.1ubuntu3_amd64 
NAME
snmptrapd.conf - configuration file for the Net-SNMP notification receiver
DESCRIPTION
The Net-SNMP notification receiver (trap daemon) uses one or more configuration files to control its
operation and how incoming traps (and INFORM requests) should be processed. This file (snmptrapd.conf)
can be located in one of several locations, as described in the snmp_config(5) manual page.
IMPORTANT
Previously, snmptrapd would accept all incoming notifications, and log them automatically (even if no
explicit configuration was provided). Starting with release 5.3, access control checks will be applied
to incoming notifications. If snmptrapd is run without a suitable configuration file (or equivalent
access control settings), then such traps WILL NOT be processed. See the section ACCESS CONTROL for more
details.
As with the agent configuration, the snmptrapd.conf directives can be divided into four distinct groups.
TRAPD BEHAVIOUR
snmpTrapdAddr [<transport-specifier>:]<transport-address>[,...]
defines a list of listening addresses, on which to receive incoming SNMP notifications. See the
section LISTENING ADDRESSES in the snmpd(8) manual page for more information about the format of
listening addresses.
The default behaviour is to listen on UDP port 162 on all IPv4 interfaces.
doNotRetainNotificationLogs yes
disables support for the NOTIFICATION-LOG-MIB. Normally the snmptrapd program keeps a record of
the traps received, which can be retrieved by querying the nlmLogTable and nlmLogvariableTable
tables. This directive can be used to suppress this behaviour.
See the snmptrapd(8) manual page and the NOTIFICATION-LOG-MIB for details.
doNotLogTraps yes
disables the logging of notifications altogether. This is useful if the snmptrapd application
should only run traphandle hooks and should not log traps to any location.
doNotFork yes
do not fork from the calling shell.
pidFile PATH
defines a file in which to store the process ID of the notification receiver. By default, this ID
is not saved.
ACCESS CONTROL
Starting with release 5.3, it is necessary to explicitly specify who is authorised to send traps and
informs to the notification receiver (and what types of processing these are allowed to trigger). This
uses an extension of the VACM model, used in the main SNMP agent.
There are currently three types of processing that can be specified:
log log the details of the notification - either in a specified file, to standard output (or
stderr), or via syslog (or similar).
execute
pass the details of the trap to a specified handler program, including embedded perl.
net forward the trap to another notification receiver.
In the following directives, TYPES will be a (comma-separated) list of one or more of these tokens. Most
commonly, this will typically be log,execute,net to cover any style of processing for a particular
category of notification. But it is perfectly possible (even desirable) to limit certain notification
sources to selected processing only.
authCommunity TYPES COMMUNITY [SOURCE [OID | -v VIEW ]]
authorises traps (and SNMPv2c INFORM requests) with the specified community to trigger the types
of processing listed. By default, this will allow any notification using this community to be
processed. The SOURCE field can be used to specify that the configuration should only apply to
notifications received from particular sources - see snmpd.conf(5) for more details.
authUser TYPES [-s MODEL] USER [LEVEL [OID | -v VIEW ]]
authorises SNMPv3 notifications with the specified user to trigger the types of processing listed.
By default, this will accept authenticated requests. (authNoPriv or authPriv). The LEVEL field
can be used to allow unauthenticated notifications (noauth), or to require encryption (priv), just
as for the SNMP agent.
With both of these directives, the OID (or -v VIEW) field can be used to retrict this
configuration to the processing of particular notifications.
Note: Unlike the VACM processing described in RFC 3415, this view is only matched against the
snmpTrapOID value of the incoming notification. It is not applied to the payload varbinds
held within that notification.
authGroup TYPES [-s MODEL] GROUP [LEVEL [OID | -v VIEW ]]
authAccess TYPES [-s MODEL] GROUP VIEW [LEVEL [CONTEXT]]
setAccess GROUP CONTEXT MODEL LEVEL PREFIX VIEW TYPES
authorise notifications in the specified GROUP (configured using the group directive) to trigger
the types of processing listed. See snmpd.conf(5) for more details.
createUser [-e ENGINEID] username (MD5|SHA|SHA-512|SHA-384|SHA-256|SHA-224) authpassphrase [DES|AES]
See the snmpd.conf(5) manual page for a description of how to create SNMPv3 users. This is
roughly the same, but the file name changes to snmptrapd.conf from snmpd.conf.
disableAuthorization yes
will disable the above access control checks, and revert to the previous behaviour of accepting
all incoming notifications.
LOGGING
format1 FORMAT
format2 FORMAT
specify the format used to display SNMPv1 TRAPs and SNMPv2 notifications respectively. Note that
SNMPv2c and SNMPv3 both use the same SNMPv2 PDU format.
format DESTINATION FORMAT
specify the format used for different destinations. DESTINATION is one of: print, print1, print2,
syslog, syslog1, syslog2, execute, execute1, execute2. print1 is used for printing SNMPv1 traps,
print2 is for SNMPv2. print is used for both versions. syslog is similarly used when sending
traps to syslog, and execute used when sending traps to a program such as traptoemail(1).
The default formats are
format print1 %.4y-%.2m-%.2l %.2h:%.2j:%.2k %B [%b] (via %A [%a]): %N\n\t%W Trap (%q) Uptime:
%#T\n%v\n
format print2 %.4y-%.2m-%.2l %.2h:%.2j:%.2k %B [%b]:\n%v\n
format syslog1 %a: %W Trap (%q) Uptime: %#T%#v\n
format syslog2 %B [%b]: Trap %#v\n
format execute %B\n%b\n%V\n%v\n
See snmptrapd(8) for the layout characters available.
ignoreAuthFailure yes
instructs the receiver to ignore authenticationFailure traps.
Note: This currently only affects the logging of such notifications. authenticationFailure traps
will still be passed to trap handler scripts, and forwarded to other notification
receivers. This behaviour should not be relied on, as it is likely to change in future
versions.
logOption string
specifies where notifications should be logged - to standard output, standard error, a specified
file or via syslog. See the section LOGGING OPTIONS in the snmpcmd(1) manual page for details.
outputOption string
specifies various characteristics of how OIDs and other values should be displayed. See the
section OUTPUT OPTIONS in the snmpcmd(1) manual page for details.
MySQL Logging
There are two configuration variables that work together to control when queued traps are logged to the
MySQL database. A non-zero value must be specified for sqlSaveInterval to enable MySQL logging.
sqlMaxQueue max
specifies the maximum number of traps to queue before a forced flush to the MySQL database.
sqlSaveInterval seconds
specified the number of seconds between periodic queue flushes. A value of 0 for will disable
MySQL logging.
NOTIFICATION PROCESSING
As well as logging incoming notifications, they can also be forwarded on to another notification
receiver, or passed to an external program for specialised processing.
traphandle OID|default PROGRAM [ARGS ...]
invokes the specified program (with the given arguments) whenever a notification is received that
matches the OID token. For SNMPv2c and SNMPv3 notifications, this token will be compared against
the snmpTrapOID value taken from the notification. For SNMPv1 traps, the generic and specific
trap values and the enterprise OID will be converted into the equivalent OID (following RFC 2576).
Typically, the OID token will be the name (or numeric OID) of a NOTIFICATION-TYPE object, and the
specified program will be invoked for notifications that match this OID exactly. However this
token also supports a simple form of wildcard suffixing. By appending the character ยด*' to the
OID token, the corresponding program will be invoked for any notification based within subtree
rooted at the specified OID. For example, an OID token of .1.3.6.1.4.1* would match any
enterprise specific notification (including the specified OID itself). An OID token of
.1.3.6.1.4.1.* would would work in much the same way, but would not match this exact OID - just
notifications that lay strictly below this root. Note that this syntax does not support full
regular expressions or wildcards - an OID token of the form oid.*.subids is not valid.
If the OID field is the token default then the program will be invoked for any notification not
matching another (OID specific) traphandle entry.
Details of the notification are fed to the program via its standard input. Note that this will always
use the SNMPv2-style notification format, with SNMPv1 traps being converted as per RFC 2576, before being
passed to the program. The input format is, if you use the default set by the "format execute
%B\n%b\n%V\n%v\n", one entry per line:
HOSTNAME
The name of the host that sent the notification, as determined by gethostbyaddr(3).
ADDRESS
The transport address, like
"[UDP: [172.16.10.12]:23456->[10.150.0.8]]"
VARBINDS
A list of variable bindings describing the contents of the notification, one per line. The
first token on each line (up until a space) is the OID of the varind, and the remainder of
the line is its value. The format of both of these are controlled by the outputOption
directive (or similar configuration).
The first OID should always be SNMPv2-MIB::sysUpTime.0, and the second should be
SNMPv2-MIB::snmpTrapOID.0. The remaining lines will contain the payload varbind list. For
SNMPv1 traps, the final OID will be SNMPv2-MIB::snmpTrapEnterprise.0.
Example:
A traptoemail script has been included in the Net-SNMP package that can be used within a
traphandle directive:
traphandle default /usr/bin/perl /usr/bin/traptoemail -s mysmtp.somewhere.com -f
admin@somewhere.com me@somewhere.com
forward OID|default DESTINATION
forwards notifications that match the specified OID to another receiver listening on DESTINATION.
The interpretation of OID (and default) is the same as for the traphandle directive).
See the section LISTENING ADDRESSES in the snmpd(8) manual page for more information about the
format of listening addresses.
addForwarderInfo 1|yes|true|0|no|false
Each time a trap is forwarded, add an OID with the IP address of the system from which the trap
has been received. The following OID is added: .1.3.6.1.6.3.18.1.3.x (SNMP-COMMUNITY-
MIB::snmpTrapAddress.x) where x is the lowest index >= 0 that does not yet occur in the trap
payload. The end recipient (i.e. the monitoring system) can determine the IPv4 address of the
original sender by looking for the varbind with OID snmpTrapAddress.0. If that OID is not
populated it means that the trap has been sent directly or in other words that it has not been
forwarded.
NOTES
o The daemon blocks while executing the traphandle commands. (This should be fixed in the future
with an appropriate signal catch and wait() combination).
o All directives listed with a value of "yes" actually accept a range of boolean values. These will
accept any of 1, yes or true to enable the corresponding behaviour, or any of 0, no or false to
disable it. The default in each case is for the feature to be turned off, so these directives are
typically only used to enable the appropriate behaviour.
FILES
/etc/snmp/snmptrapd.conf
SEE ALSO
snmp_config(5), snmptrapd(8), syslog(8), traptoemail(1), variables(5), netsnmp_config_api(3).