Essential SNMP, 2nd Edition

Net-SNMP

Note that when you download and build the source distribution for Net-SNMP, you must explicitly tell the configure command to install the Perl modules as well. You do so like this:

    $ ./configure --with-perl-modules

The use statement for this module looks like the following:

    use SNMP;

Beyond this, the actual usage of the Net-SNMP Perl module is broken into two categories, which are discussed next.

MIB Management Routines

By default, when you use this Perl module it will load all the MIB files located in the default location, /usr/local/share/snmp/mibs. This means you can use names like sysDescr and not have to remember the OIDs for these objects. But if you want to use some private MIB, there are routines that can help you with this. We'll discuss the two more commonly used ones.

&SNMP::loadModules(<mod>,...)

The &SNMP::loadModules() method is used to load a particular MIB file. If you simply copy your MIB file to the normal location (/usr/local/share/snmp/mibs), the Net-SNMP library will not automatically load it. It has an internal list of MIB files it knows about (these are installed when you build the Net-SNMP package). This routine can be used to load a specific MIB, list of MIBs, or all MIBs. For example, this line of code will load all MIB files, including any you copied to the default location:

    &SNMP::loadModules('ALL');

Alternatively, you could have invoked this routine like so:

    &SNMP::loadModules('IEEE802dot11-MIB');

This loads the 802.11 MIB we installed. How did we know ...