How reliable are SNMP Agents in their adherence to protocol and MIB Standards? (NETIQKB43541)

How reliable are SNMP Agents in their adherence to protocol and MIB Standards?
How reliable are SNMP Agents in their adherence to protocol and Management Information Base (MIB) Standards?

SNMP stands for Simple Network Management Protocol. Unfortunately, vendor SNMP Agents commonly do not adhere completely to protocol and Management Information Base (MIB) standards. This is partially due to:

• Individual Vendor interpretation of the SNMP standards
• SNMP Agents containing software issues like any other application
• In practice, Vendors not fully implementing support for an MIB.

If the NetIQ AppManager for SNMP module (SNMP Toolkit) is not behaving as expected, it is more likely to be a problem with the SNMP Agent than with the Toolkit. The following list describes some common SNMP Agent issues:

1. SNMP Agents normally do not respond (timeout) if the community string is invalid. However, some SNMP Agents will respond with an error such as "Bad Value" or "No Such Value".
2. An SNMP Attribute defined in an MIB is not always present in the SNMP Agent. SNMP Values are often missing or invalid. It all depends on how completely the vendor supports the MIB. Missing values normally result in an SNMP Response Error Event from the SNMP Toolkit.
3. SNMP Tables commonly have missing values interspersed in the Table Rows. Missing Values will cause the SyncGetTable/SyncPollTable Knowledge Script(s) to abort retrieval of the table once a missing value is reached, as it causes the SNMP Table Walk to fall out of sync.
4. Vendor Proprietary MIB files sometimes do not completely adhere to SNMP's defined ASN.1 syntax, but just happen to work with the vendor's SNMP Agent anyway. Loading MIBs with invalid ASN.1 syntax into the SNMP Toolkit will cause MIB Parsing Errors to be reported.

Formerly known as NETIQKB43541