Question

I’m faced with the need to write a new MIB description. Does anyone know of a good tutorial or reference? I seem to find lots of stuff about using SNMP and Net-SNMP has decent stuff about implementing an agent, but it seems like the only real sources on writing the MIBs are RFCs.

Answer 1

Mg Soft company is selling a very good tool called “Mib Browser” but they also edit a product called “Visual MIB Builder”, which provide an easy way to build MIBs without dealling with ASN1 syntax.

Mibs are built on ASN1 syntax, you definitively not need to understand all ASN1 language. I wrote a few PPT slides to explain that, but they are in french.

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Edited (1)

I built MIBs twelve years ago, and I learnt by myself with a couple of books (Practical Guide to Snmpv3 and Network Management, Essential SNMP).

On the semantic point of view the first three advices that come in my mind are :

1. Learn how tables are built and how they works (get-next usage and index)
2. Have a look to Textual Conventions, they mostly appears in SNMPv2 giving names to implicit usages in SNMPv1. For example you’ll read how TestAndIncr provides the mutex semantic. They are improved in SNMPv3. But understand that you have to provide the code for doing that in your agent, they are just TCs.
3. I learnt a lot in understanding how RMON1 MIB was working, and especialy the usage of configuration tables.

Just an advice, SNMP is a nice protocol, it’s a bit old, and except with SNMPV3 it still lives in a boudhist world. I just mean that V1 and V2 are just ignoring the security point of view. So be careful with writable leafs, you can deploy an active agent protecting SNMP ports with IPSec but it’s ‘expensive’.

Do you have a look to Web-Based Enterprise Management (WBEM) ? On Windows I play with WMI which is Microsoft adaptation of this standard, but on Linux you can play with OpenPegasus.