Set the Edit Configuration Mode in a NETCONF Session

By default, the NETCONF server merges new configuration data into the candidate configuration or open configuration database. Thus, if you do not specify an edit configuration mode, the device merges the new configuration elements into the existing configuration.

Merging configurations is performed according to the following rules. (The rules also apply when updating configuration data in an open configuration database, for example, the ephemeral database, but for simplicity the following discussion refers to the candidate configuration only.)

• A configuration element (hierarchy level or configuration object) that exists in the candidate configuration but not in the new configuration remains unchanged.

• A configuration element that exists in the new configuration but not in the candidate configuration is added to the candidate configuration.

• If a configuration element exists in both configurations, the following results occur:

  • If a child statement of the configuration element (represented by a child tag element) exists in the candidate configuration but not in the new configuration, it remains unchanged.

  • If a child statement exists in the new configuration but not in the candidate, it is added to the candidate configuration.

  • If a child statement exists in both configurations, the value in the new data replaces the value in the candidate configuration.

To explicitly specify that data be merged, the application includes the <default-operation> tag element with the value merge in the <edit-config> tag element.

<rpc>
    <edit-config>
        <default-operation>merge</default-operation> 
        <!-- other child tag elements of the <edit-config> tag element -->
    </edit-config>
</rpc>
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In the replace edit configuration mode, the new configuration data completely replaces the data in the candidate configuration or open configuration database. To specify that the data be replaced, the application includes the <default-operation> tag element with the value replace in the <edit-config> tag element.

<rpc>
    <edit-config>
        <default-operation>replace</default-operation> 
    </edit-config>
</rpc>
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We recommend using the global replace mode only when you plan to completely overwrite the existing configuration with new configuration data. Furthermore, when the edit configuration mode is set to replace, we do not recommend using the operation attribute for individual configuration elements.

You can also replace individual configuration elements while merging or creating others. See Replace Configuration Elements Using NETCONF.

In the none (no-change) edit configuration mode, changes to the configuration are ignored. This mode is useful when you are deleting elements, and it prevents the NETCONF server from creating parent hierarchy levels for an element that is being deleted. For more information, see Delete Configuration Elements Using NETCONF.

To set the no-change edit configuration mode globally, the application includes the <default-operation> tag element with the value none in the <edit-config> tag element.

<rpc>
  <edit-config>
    <default-operation>none</default-operation>
  </edit-config>
</rpc>

When you use the <default-operation> tag to globally set the edit configuration mode to none to indicate the no-change mode, you can still override this mode and specify a different edit configuration mode for individual elements by including the operation attribute in the element’s tag. For example:

<rpc>
  <edit-config>
    <default-operation>none</default-operation>
    <config>
      <configuration>
        <system>
          <services>
            <outbound-ssh>
              <client>
                <name>test</name>
                <device-id>test</device-id>
                <keep-alive>
                  <retry operation="merge">4</retry>
                  <timeout operation="merge">15</timeout>
                </keep-alive>
              </client>
            </outbound-ssh>
          </services>
        </system>
      </configuration>
    </config>
  </edit-config>
</rpc>