SNMP_CONFIG(5)							     Net-SNMP							    SNMP_CONFIG(5)

NAME

       snmp_config - handling of Net-SNMP configuration files

DESCRIPTION

       The  Net-SNMP package uses various configuration files to configure its applications.  This manual page merely describes the overall nature
       of them, so that the other manual pages don't have to.

DIRECTORIES SEARCHED

       First off, there are numerous places that configuration files can be found and read from.  By default, the applications look for configura-
       tion files in the following 4 directories, in order: /etc/snmp, /usr/share/snmp, /usr/lib/snmp, and $HOME/.snmp.  In each of these directo-
       ries, it looks for files with the extension of both conf and local.conf (reading the second ones  last).   In  this  manner,  there  are  8
       default places a configuration file can exist for any given configuration file type.

       Additionally, the above default search path can be overridden by setting the environment variable SNMPCONFPATH to a colon-separated list of
       directories to search for.  The path for the persistent data should be included when running applications that use persistent storage, such
       as snmpd.

       Applications will read persistent configuration files in the following order of preference:

	      file in SNMP_PERSISTENT_FILE environment variable

	      directories in SNMPCONFPATH environment variable

	      directory defined by persistentDir snmp.conf variable

	      directory in SNMP_PERSISTENT_DIR environment variable

	      default /var/db/net-snmp directory

       Finally, applications will write persistent configuration files in the following order of preference:

	      file in SNMP_PERSISTENT_FILE environment variable

	      directory defined by persistentDir snmp.conf variable

	      directory in SNMP_PERSISTENT_DIR environment variable

	      default /var/db/net-snmp directory

       Note:  When using SNMP_PERSISTENT_FILE, the filename should match the application name.	For example, /var/net-snmp/snmpd.conf.

CONFIGURATION FILE TYPES

       Each  application  may  use multiple configuration files, which will configure various different aspects of the application.  For instance,
       the SNMP agent (snmpd) knows how to understand configuration directives in both the snmpd.conf and the  snmp.conf  files.   In  fact,  most
       applications  understand  how  to read the contents of the snmp.conf files.  Note, however, that configuration directives understood in one
       file may not be understood in another file.  For further information, read the associated manual page with each	configuration  file  type.
       Also,  most  of	the  applications  support a -H switch on the command line that will list the configuration files it will look for and the
       directives in each one that it understands.

       The snmp.conf configuration file is intended to be a application suite wide configuration file that supports directives that are useful for
       controlling the fundamental nature of all of the SNMP applications, such as how they all manipulate and parse the textual SNMP MIB files.

SWITCHING CONFIGURATION TYPES IN MID-FILE
       It's  possible  to  switch  in mid-file the configuration type that the parser is supposed to be reading.  Since that sentence doesn't make
       much sense, lets give you an example: say that you wanted to turn on packet dumping output for the agent by default, but you didn't want to
       do  that  for the rest of the applications (ie, snmpget, snmpwalk, ...).  Normally to enable packet dumping in the configuration file you'd
       need to put a line like:

	      dumpPacket true

       into the snmp.conf file.  But, this would turn it on for all of the applications.  So, instead, you can put the same line in the snmpd.conf
       file so that it only applies to the snmpd daemon.  However, you need to tell the parser to expect this line.  You do this by putting a spe-
       cial type specification token inside a [] set.  In other words, inside your snmpd.conf file you could put the above snmp.conf directive	by
       adding a line like so:

	      [snmp] dumpPacket true

       This  tells the parser to parse the above line as if it were inside a snmp.conf file instead of an snmpd.conf file.  If you want to parse a
       bunch of lines rather than just one then you can make the context switch apply to the remainder of the  file  or  until	the  next  context
       switch directive by putting the special token on a line by itself:

	      # make this file handle snmp.conf tokens:
	      [snmp]
	      dumpPacket true
	      logTimestamp true
	      # return to our original snmpd.conf tokens:
	      [snmpd]
	      rocommunity mypublic

COMMENTS

       Any lines beginning with the character '#' in the configuration files are treated as a comment and are not parsed.

INCLUDING OTHER CONFIGURATION FILES

       It is possible to include other configuration files for processing during normal configuration file processing.:

	      # include site specific config
	      include site.conf

       This will search every directory in the configuration path for files
       named site.conf, and will process those files before returning to the
       processing of the original file. Note that if '.conf' is omitted,
       it will be appended. That is, all configuration files must end
       in '.conf'.

API INTERFACE

       Information  about  writing  C  code that makes use of this system in either the agent's MIB modules or in applications can be found in the
       netsnmp_config_api(3) manual page.

SEE ALSO

       snmpconf(1), netsnmp_config_api(3), snmp.conf(5), snmpd.conf(5)

V5.6								    08 Mar 2010 						    SNMP_CONFIG(5)