Netconf

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Netconf is a network management protocol developed in the IETF by the Netconf working group. It was published as RFC 4741.

The NETCONF protocol provides mechanisms to install, manipulate, and delete the configuration of network devices. It also can perform some monitoring functions. It uses an Extensible Markup Language (XML) based data encoding for the configuration data as well as the protocol messages. The NETCONF protocol operations are realized on top of a simple Remote Procedure Call (RPC) layer.

Netconf defines three transport mappings

SSH (RFC 4742), which is mandatory to implement
SOAP (RFC 4743)
BEEP (RFC 4744)

NETCONF can be conceptually partitioned into four layers:

             Layer                      Example
        +-------------+      +-----------------------------+
    (4) |   Content   |      |     Configuration data      |
        +-------------+      +-----------------------------+
               |                           |
        +-------------+      +-----------------------------+
    (3) | Operations  |      | <get-config>, <edit-config> |
        +-------------+      +-----------------------------+
               |                           |
        +-------------+      +-----------------------------+
    (2) |     RPC     |      |    <rpc>, <rpc-reply>       |
        +-------------+      +-----------------------------+
               |                           |
        +-------------+      +-----------------------------+
    (1) |  Transport  |      |   BEEP, SSH, SSL, console   |
        |   Protocol  |      |                             |
        +-------------+      +-----------------------------+

The Netconf working group is currently working on an extension to support subscribing and receiving asynchronous event notifications.

[edit] History

The IETF developed SNMP in the late 1980s and it proved to be a very popular network management protocol. In the early part of the 21st century it became apparent that in spite of what was originally intended, SNMP was not being used to configure network equipment, but was mainly being used for network monitoring. In 2002, the Internet Architecture Board and key members of the IETF's network management community got together with network operators to discuss the situation. The results of this meeting are documented in RFC 3535. It turned out that operators were primarily using proprietary Command Line Interfaces (CLI) to configure their boxes. This had a number of features that the operators liked, including the fact that it was text-based, as opposed to the BER-encoded SNMP. In addition, many equipment vendors did not provide the option to completely configure their devices via SNMP. As operators generally liked to write scripts to help manage their boxes, they did find the CLI lacking in a number of ways. Most notably was the unpredictable nature of the output. The content and formatting of output was prone to change in unpredictable ways.

Around this same time, Juniper Networks had been experimenting with an XML-based network management system. This was brought to the IETF and shared with the broader community.

Collectively, these two events led the IETF to the creation of a protocol which it hopes will better align with the needs of network operators and equipment vendors.