Managing NerveCenter - Managing Management Information Bases (MIBs) - Adding or Removing MIB Definitions -
Definitions from other sources      Compiling the NerveCenter MIB

Adding or Removing MIB Definitions

The MIB compiler (mibcomp) compiles the MIB definitions referenced in a text file. You can add references to or remove them from this file to control what definitions are compiled into the NerveCenter MIB.

Add MIB definitions if you want to monitor additional devices. Remove MIB definitions if you are no longer monitoring the devices supported by those definitions. (Removing the definitions is not required; however, the NerveCenter MIB will be smaller, which can improve client performance and will make managing the MIB easier.)

If you are using NerveCenter with a network management platform and both applications are monitoring the same agents, make sure both applications are using the correct MIBs for those agents.

See Sources of MIB Definitions for a list of MIB definitions that are shipped with NerveCenter and what standards MIB definitions are not shipped with NerveCenter must follow.

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   NerveCenter installs the file nervectr38.mib and mibcomp38.txt. These are copies of the default nervectr.mib and mibcomp.txt in case you need to revert to an unchanged MIB definitions.

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The MIB compiler (mibcomp) compiles the MIB definitions referenced in a text file. You can add references to this file to control what definitions are compiled into the NerveCenter MIB.

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   If a MIB module depends on information in another MIB module you must reference it before the module that requires the information in mibcomp.txt. That is, if mymibA depends on mymibB, you must include mymibB before mymibA in mibcomp.txt.

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If dependant MIB module references are out of order, you recieve an error similar to the following:

In this example, rfc1573b.asn1 depends upon another mib to define interfaces. You must find the mib that defines interfaces and include it before rfc1573b.asn1 in mibcomp.txt. To find a MIB that defines interfaces, you search the other MIB modules looking for the following:

Now you can name the file that contains this line, in this case rfc1213.asn1, before rfc1573b.asn1.

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   All SMIv1 compliant MIB modules must be included in mibcomp.txt before the line
# * * * End of SMIv1 / SNMPv1 MIB Modules * * *
All SMIv2 compliant MIB modules must be referenced after this line.

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You can tell the difference between a SMIv1 module and an SMIv2 module by searching the *.asn1 file for "MAX-ACCESS.

Sample SMIv1 SysUpTime definition	Sample SMIv2 SysUpTime definition
sysUpTime OBJECT-TYPE SYNTAX TimeTicks ACCESS read-only STATUS mandatory DESCRIPTION "The time (in hundredths of a second) since the network management portion of the system was last re-initialized." ::= { system 3 }	sysUpTime OBJECT-TYPE SYNTAX TimeTicks MAX-ACCESS read-only STATUS current DESCRIPTION "The time (in hundredths of a second) since the network management portion of the system was last re-initialized." ::= { system 3 }

Any use of ACCESS within a *.asn1 named in the SMIv2 area of mibcomp.txt causes an error. Any use of MAX-ACCESS within a *.asn1 named in the SMIv1 area of mibcomp.txt causes an error.

 
  To modify the mibcomp text file:

1. If you previously modified mibcomp.txt or nervectr.mib, make back-up copies of them in case you want to recover your changes.

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      You can modify these files directly; they will not be overwritten during the next installation.

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2. In a text editor, open the file.
3. To add definitions, do one of the following:
   • Remove the pound sign (#) in front of definitions that are currently commented out.
   • Add lines for new definitions. Include the directory and the name of the file. For example:

     users/companyXYZ.asn1

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        On Windows, use backslashes. On UNIX, you must use slashes.

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4. To remove definitions, do one of the following:
   • Comment out definitions by adding a pound sign (#) in front of the appropriate lines. For example:

     # xyplex

     #

     # vendors/xyplex/xyplex.asn1

   • Delete the appropriate lines.
5. Save and close the file.

You have updated the file that includes references to the MIB definitions you need. Now, you must compile the NerveCenter MIB using the file you just created. See Compiling the NerveCenter MIB.