Converting MIBs Using mib2opennms
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mib2opennms How-To

This little document provides an explanation of how to import SNMP MIBs into OpenNMS, using the opensource tool 'mib2opennms'. In reality we don't import the whole MIB, we just take out the trap definitions (if there are some) from the mib and add them as events to opennms.

Why import the OIDs using this tool?

OpenNMS has the ability to receive SNMP traps; In order to do that, OpenNMS must know how to treat each event (thus requires a description for each OID that it receives). Normally if you don't do that you will receive anoying messages like the following on your event database: 

Received unformatted enterprise event (enterprise:.1.3.6.1.4.1.2021.250.10 generic:0 specific:0). 0 args:

Also importing the OIDs by hand is error prone and tedious, so the use of this tool is a must when adding new OIDs.

Download and build the software

There are several alternatives (RPM, source code). Look for it in the contrib directory of OpenNMS.

openSUSE users may download the prepackaged RPM from http://download.opensuse.org/repositories/server:/monitoring:/opennms/

Recent versions of OpenNMS have seperated mib2opennms to it's own project. If it is not in your contrib directory, you can get it from source SVN: 

svn co https://opennms.svn.sourceforge.net/svnroot/opennms/mib2opennms/trunk mib2opennms

Then, compile and install. The latest install docs are located in INSTALL file for compiling options and basic instructions. But generally: 

[username@host ~]# cd mib2opennms
[username@host mib2opennms]# ./configure
[username@host mib2opennms]# make && make install

If the configure script is missing you can rebuild it (needs automake/autoconf installed) with 

 autoreconf -fvi

If the configure script stops because smi.h is missing look out for libsmi for your system (you may need the libsmi-devel package to get the header files).

How to use

Single MIB file

Convert a single mib file and set the value for generic to 6 with 

mib2opennms -6 mibfile.mib >mibfile.events.xml

Edit the mibfile.events.xml and add as first line a line with <events>, as last line a line with </events>. Move the file to $OPENNMS_HOME/etc/events

Add a line to $OPENNMS_HOME/etc/eventconf.xml like 

<event-file>events/mibfile.events.xml</event-file>

Ensure <event-file>events/default.events.xml</event-file> remains the last entry. Restart OpenNMS and the new events are ready to go.

For most trap definition in mibs this should do the job. If you have problems see the detailed configuration explanation below and in Event Configuration How-To

Batch processing

It is better to get a detailed list of OIDs in the form of XML files; so that you can choose what to cut/paste into your "eventconf.xml," instead of a huge (and useless) list of OIDs.

Here is a Bash script that can do the nasty work for you (take care to define the appropiate variables first): 

# <----- CUT HERE ----->

#!/bin/bash
#
# This program generates a list of XML files to be used with OpenNMS and the 
# "event" section.
# Author: Jose Vicente Nunez Zuleta (josevnz@newbreak.com)
# Requires: mib2openms (http://www.tompa.nu/mib2opennms/)
#

MIBPATH="/usr/share/snmp/mibs:/usr/share/mibs:/home/josevnz/mibs"
MIBDEF=$1
destdir=$2

if [ -z $MIBDEF ] ; then
cat <<EOF;
[ERROR]:
You must supply values for the mib directory. Examples:

/home/josevnz/mibs

/usr/share/snmp/mibs

Then the script will locate all the '*.txt' files present.


EOF
exit 1
fi


mibc="/usr/bin/mib2opennms"
mkdir="/bin/mkdir"
perl="/usr/bin/perl" # sed SUCKS!!! ;)

# Use the user destination dir if present
if [ -z $destdir ] ; then
  destdir="/tmp";
fi

if [ ! -e $destdir ] ; then
  $mkdir -p $destdir
  if [ $? -ne 0 ] ; then
    echo "Error creating destination dir"
  fi
fi

# Get the list of all the MIBs on this system
LIST=`find $MIBDEF -type f -name '*.txt' | /usr/bin/xargs`
if [ $? -ne 0 ] ; then
  echo "Error locating the MIBS"
fi

for file in $LIST; do
  # Get the mib name from the file
  mib=`echo $file |$perl -e' while(<STDIN>) { $_ = m#.*/(.*)\.txt#; print $1 }'`
  echo "Processing: $mib"
  # Generate a OpenNMS MIB xml file for each located mib
  COMMAND="$mibc -f "$destdir/$mib.xml" -m $MIBPATH $file"
  echo $COMMAND
  $COMMAND
  if [ $? -ne 0 ]; then
   echo "MIB conv failed"
  fi
done

# <----- CUT HERE ----->

Then you can call it like this: 

 ./generate_mibs.bsh /home/josevnz/mibs 1> output.txt 2> errors.txt

Resources

List of extracted (and ready to use) MIBs:

More on mib2opennms

This came up on the discussion list, so I thought it should go here.

Q: I am trying to get the Juniper MIBs into OpenNMS, but I can't get mib2opennms to work. I only get segmentation faults: 

# mib2opennms mib-jnx-ipv6.txt
mib2opennms version 0.2.2
Segmentation fault

A: This usually means that there is a problem with the ASN.1 notation in your mibs.

I don't get a seg fault on that mib, but since: 

grep NOTIF mib-jnx-ipv6.txt

and 

grep TRAP mib-jnx-ipv6.txt

return nothing, there are no events defined in that MIB.

A quick search shows the following files support NOTIFICATION-TYPE objects: 

Stormbringer:~/Desktop/JuniperMibs tarus$ grep -l NOTIF *
mib-jnx-bgpmib2.txt
mib-jnx-cfgmgmt.txt
mib-jnx-chassis.txt
mib-jnx-coll.txt
mib-jnx-ldp.txt
mib-jnx-mpls.txt
mib-jnx-ping.txt
mib-jnx-pmon.txt
mib-jnx-rmon.txt
mib-jnx-sonet.txt
mib-jnx-sonetaps.txt
mib-jnx-vpn.txt

Let's check out the first one. if I run: 

/usr/local/bin/mib2opennms mib-jnx-bgpmib2.txt

I get: 

        <mask>
                <maskelement>
                        <mename>id</mename>
                        <mevalue>.0.1.1</mevalue>
                </maskelement>
                <maskelement>
                        <mename>generic</mename>
                        <mevalue>0</mevalue>
                </maskelement>
                <maskelement>
                        <mename>specific</mename>
                        <mevalue>1</mevalue>
                </maskelement>
        </mask>

Note that the id looks wrong. It should be something like .1.3.6.1.4.1.x

This usually means that there is a broken import somewhere, so we should include the MIB files in the current directory: 

/usr/local/bin/mib2opennms -m. mib-jnx-bgpmib2.txt
        <mask>
                <maskelement>
                        <mename>id</mename>
                        <mevalue>.0.1.1</mevalue>
                </maskelement>
                <maskelement>
                        <mename>generic</mename>
                        <mevalue>0</mevalue>
                </maskelement>
                <maskelement>
                        <mename>specific</mename>
                        <mevalue>1</mevalue>
                </maskelement>
        </mask>

Hrm, not much better, and adding the path to the default MIBs doesn't help either: 

/usr/local/bin/mib2opennms -m/usr/share/snmp/mibs:. mib-jnx-bgpmib2.txt

So, it's time to look into the mib file. The first NOTIFICATION-TYPE object is: 

jnxBgpM2Established NOTIFICATION-TYPE
    ::= { jnxBgpM2BaseNotifications 1 }

So let's work backwards. 

jnxBgpM2BaseNotifications
    OBJECT IDENTIFIER ::= { jnxBgpM2BaseScalars 0 }

jnxBgpM2BaseScalars
    OBJECT IDENTIFIER ::= { jnxBgpM2 1 }

jnxBgpM2 MODULE-IDENTITY
     ::= { jnxBgpM2Experiment 1 }

Now, jnxBgpM2Experiment comes from: 

jnxBgpM2Experiment
    FROM JUNIPER-EXPERIMENT-MIB

Therein lies the problem. As mentioned in the README: 

If mib2opennms complains about a missing MIB, be sure that there is a file
in your "-m" MIB path that has the *exact* name as the MIB it is complaining
about.

For example, if it complains "Can't find RFC-1213" and you have a file in your path called "RFC1213", you must rename it or copy it to "RFC-1213".

The extensions .txt, .my and I believe .mib are acceptable, so in the above example, RFC-1213.txt should work."

Well, there is no file called JUNIPER-EXPERIMENT-MIB. So: 

cp mib-jnx-exp.txt JUNIPER-EXPERIMENT-MIB

and rerun: 

/usr/local/bin/mib2opennms -m/usr/share/snmp/mibs:.  mib-jnx-bgpmib2.txt
        <mask>
                <maskelement>
                        <mename>id</mename>
                        <mevalue>.0.5.1.1.1</mevalue>
                </maskelement>
                <maskelement>
                        <mename>generic</mename>
                        <mevalue>0</mevalue>
                </maskelement>
                <maskelement>
                        <mename>specific</mename>
                        <mevalue>1</mevalue>
                </maskelement>
        </mask>

Better. More research shows that the JUNIPER-SMI MIB is referenced by JUNIPER-EXPERIMENT-MIB: 

cp mib-jnx-smi.txt JUNIPER-SMI
/usr/local/bin/mib2opennms -m/usr/share/snmp/mibs:.  mib-jnx-bgpmib2.txt
        <mask>
                <maskelement>
                        <mename>id</mename>
                        <mevalue>.1.3.6.1.4.1.2636.5.1.1.1</mevalue>
                </maskelement>
                <maskelement>
                        <mename>generic</mename>
                        <mevalue>0</mevalue>
                </maskelement>
                <maskelement>
                        <mename>specific</mename>
                        <mevalue>1</mevalue>
                </maskelement>
        </mask>

Success! The only problem is that "generic" is set to zero, so add the -6 option: 

/usr/local/bin/mib2opennms -6 -m/usr/share/snmp/mibs:.  mib-jnx-bgpmib2.txt
        <mask>
                <maskelement>
                        <mename>id</mename>
                        <mevalue>.1.3.6.1.4.1.2636.5.1.1.1</mevalue>
                </maskelement>
                <maskelement>
                        <mename>generic</mename>
                        <mevalue>6</mevalue>
                </maskelement>
                <maskelement>
                        <mename>specific</mename>
                        <mevalue>1</mevalue>
                </maskelement>
        </mask>

The final step is to manually edit the file and make it contain "events" by adding an <events> tag at the very top and an </events> tag at the very bottom. Without these tags OpenNMS will fail to start and report an error similar to org.xml.sax.SAXException: unable to find FieldDescriptor for 'mask' in ClassDescriptor of events in output.log . These tags are not added automatically so you can prepare event definitions from a large number of input files, concatenate them together and then just wrap the resulting file with the <events> tag.

The final file, including the <events> tags, can now be added to eventconf.xml via an include as above.

This is just an example of how mib2opennms should work. I don't understand the seg faults - could be an issue with the build. We don't support stuff in contrib, so anyone with come C++ experience might want to check it out for us. WORKSFORME on my Mac (built using libsmi from fink).

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