SNMP Access Agent
download ndCONF Agent Generation Package

The SNMP protocol continues to be supported by a wide range of networked devices for remote monitoring and alarms. The production level management applications and NOC centers rely on the presence of SNMP Agents in the network’s infrastructure equipment. NuDesign optionally provides full SNMPv3 capabilities in its NETCONF / YANG ndCONF Agent-based infrastructure.

A complete SNMPv3 Agent is constructed by assembling the NuDesign’s SNMPv3 Access Agent component with the YANG Datastore Server, extended using NuDesign’s ndCONF Builder, and instrumenting a set of YANG modules pre-selected during the code generation process. The MIB’s instrumentation is common with the YANG object’s instrumentation. All SNMP operations are fully supported.

When building SNMP / YANG integrated ndCONF Agent the developer has two main options concerning management objects modelling, both leading to the creation of YANG and MIB modules:

Option One: start from the existing base of MIB modules, likely already implemented for the company existing product lines. The next step would be to translate these MIB’s into the equivalent YANG modules (via an rfc6643 compliant process), then create the MIB OID Mapping file, correlating the MIB OIDs with YANG’s leaf names, and finally create a compiled MIB.xml file, all done using NuDesign tools in the process. The automatically translated YANG module might need some adjustments that result in a more “CLI access friendly” tree layout.

Option Two: start from the YANG modules that the target agent will need to implement and design the MIB modules after, re-using the object definitions of the YANG modules, manually creating the MIB OID Mapping file (correlating the MIB OIDs with YANG’s leaf names), and creating the compiled MIB.xml file using NuDesign tools in the process.

For either option, once the YANG module is designed, a resulting YANG Datastore Server extension needs to be built using NuDesign’s ndCONF Builder product. For YANG modules that include OID annotation, the ndCONF Builder automatically creates the MIB OID Mapping file, in addition to the YANG Datastore Server’s extension source code.

The so extended YANG Datastore Server along with SNMP Access Agent, the MIB OID Mapping files and compiled MIB.xml files provide full SNMPv3 access for those YANG Datastore Server objects that also have corresponding MIB objects.

The SNMP Access Agent, along with the YANG Datastore Server implement the following IETF’s SNMP standards:

• rfc7407 – A YANG Data Model for SNMP Configuration
• rfc6643 – Translation of Structure of SMIv2 MIB Modules to YANG Modules
• the IETF standard SNMPv3 modules.

The SNMP Access Agent product is provided with the following tools to enable building the SNMP access to YANG Datastore Server:

• Visual MIBuilder with an rfc6643 YANG converter extension – it provides to create a new MIB or use an existing one and translate it into the YANG module, automatically adding the MIB OID annotation for every YANG object.
• mib_2_xml compiler tool – builds a compiled MIB.xml file, a list of SMI properties for MIB objects in the “MIB view” of a YANG Datastore Server. It’s used by SNMP Access Agent in resolving the SNMP queries to the YANG Server Datastore.