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 configuration files in the following 4 directories, in order: /etc/snmp, /usr/share/snmp, /usr/lib(64)/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 configu-
       ration 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/lib/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/lib/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  under-
       stands.

       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 sen-
       tence 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 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 agent's 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)