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 dont 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
       directories,  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 configura
       tion file type.

       Additionally, the above default search path can be overridden  by  set
       ting 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/lib/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/lib/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 con
       figure 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  applica
       tions  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
       Its possible to switch in mid-file the  configuration  type  that  the
       parser  is  supposed  to  be reading.  Since that sentence doesnt 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 didnt want to
       do that for the rest of the applications (ie, snmpget, snmpwalk,  ...).
       Normally  to enable packet dumping in the configuration file youd 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 special
       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.

API INTERFACE
       Information  about  writing  C  code  that  makes use of this system in
       either the agents MIB modules or in applications can be found  in  the
       read_config(3) manual page.

SEE ALSO
       snmpconf(1), read_config(3), snmp.conf(5), snmpd.conf(5)



4th Berkeley Distribution	  5 May 2005			SNMP_CONFIG(5)