Deleting Configuration Elements Using NETCONF
In a NETCONF session with a device running Junos
OS, to delete a configuration element, including hierarchy levels
or configuration objects, from the existing configuration in the candidate
configuration or the open configuration database (if the client application
issued the Junos XML protocol <open-configuration> operation prior to executing the <edit-config> operation), a client application emits the basic tag elements described
in Changing Individual Configuration Elements Using NETCONF. It also emits the <default-operation> tag element with the value none to change
the default mode to no-change.
<rpc> <edit-config> <target> <candidate/> </target> <default-operation>none</default-operation> <!-- EITHER --> <config> <configuration> <!-- tag elements representing the configuration elements to delete --> </configuration> </config> <!-- OR --> <url> <!-- location specifier for file containing elements to delete --> </url> </edit-config> </rpc> ]]>]]>
In no-change mode, existing configuration elements remain unchanged
unless the corresponding element in the new configuration has the operation="delete" attribute in its opening tag. This
mode prevents the NETCONF server from creating parent hierarchy levels
for an element that is being deleted. We recommend that the only operation
performed in no-change mode be deletion. When merging, replacing,
or creating configuration elements, client applications use merge
mode.
To represent each configuration element being deleted (either
within the <config> tag element or in
the file named by the <url> tag element),
the application emits the tag elements representing its parent hierarchy
levels, as described in Changing Individual Configuration Elements Using NETCONF. The tag element
in which the operation="delete" attribute
is included depends on the element type, as described in the following
sections:
Deleting a Hierarchy Level or Container Object
To delete a hierarchy level and all of its children (or a container
object that has children but no identifier), a client application
includes the operation="delete" attribute
in the empty tag that represents the level:
<configuration> <!-- opening tags for each parent level --> <level-to-delete operation="delete"/> <!-- closing tags for each parent level --> </configuration>
We recommend that the application set the default mode to no-change
by including the <default-operation> tag element with the value none, as described
in Setting the Edit Configuration Mode in a NETCONF Session. For more information about hierarchy
levels and container objects, see Mapping Configuration Statements to Junos XML Tag Elements.
The following example shows how to remove the [edit protocols ospf] hierarchy level of the candidate configuration:
Deleting a Configuration Object That Has an Identifier
To delete a configuration object that has an identifier, a client
application includes the operation="delete" attribute in the container tag element for the object. Inside the
container tag element, it includes the identifier tag element only,
not any tag elements that represent other characteristics. In the
following, the identifier tag element is called <name>:
<configuration> <!-- opening tags for each parent of the object --> <object operation="delete"> <name>identifier</name> </object> <!-- closing tags for each parent of the object --> </configuration>
The delete attribute appears
in the opening container tag, not in the identifier tag element. The
presence of the identifier tag element results in the removal of the
specified object, not in the removal of the entire hierarchy level
represented by the container tag element.
We recommend that the application set the default mode to no-change
by including the <default-operation> tag element with the value none, as described
in Setting the Edit Configuration Mode in a NETCONF Session. For more information about identifiers,
see Mapping Configuration Statements to Junos XML Tag Elements.
The following example shows how to remove the user object barbara from the [edit system login user] hierarchy level in the candidate configuration:
Deleting a Single-Value or Fixed-Form Option from a Configuration Object
To delete from a configuration object either a fixed-form option
or an option that takes just one value, a client application includes
the operation="delete" attribute in the
tag element for the option. In the following, the identifier tag element
for the object is called <name>. (For
information about deleting an option that can take multiple values,
see Deleting Values from a Multi-value Option of a Configuration Object.)
<configuration> <!-- opening tags for each parent of the object --> <object> <name>identifier</name> <!-- if object has an identifier --> <option1 operation="delete"> <option2 operation="delete"> <!-- tag elements for other options to delete --> </object> <!-- closing tags for each parent of the object --> </configuration>
We recommend that the application set the default mode to no-change
by including the <default-operation> tag element with the value none, as described
in Setting the Edit Configuration Mode in a NETCONF Session. For more information about options,
see Mapping Configuration Statements to Junos XML Tag Elements.
The following example shows how to remove the fixed-form disable option at the [edit forwarding-options sampling] hierarchy level:
Deleting Values from a Multi-value Option of a Configuration Object
As described in Mapping Configuration Statements to Junos XML Tag Elements, some Junos OS configuration objects are leaf statements that have multiple values. In the formatted ASCII CLI representation, the values are enclosed in square brackets following the name of the object:
object[value1 value2 value3 ...];
The Junos XML representation does not use a parent tag for the
object, but instead uses a separate instance of the object tag element
for each value. In the following, the identifier tag element is called <name>:
<parent-object> <name>identifier</name> <object>value1</object> <object>value2</object> <object>value3</object> </parent-object>
To remove one or more values for such an object, a client application
includes the operation="delete" attribute
in the opening tag for each value. It does not include tag elements
that represent values to be retained. The identifier tag element in
the following is called <name>:
<configuration> <!-- opening tags for each parent of the parent object --> <parent-object> <name>identifier</name> <object operation="delete">value1</object> <object operation="delete">value2</object> </parent-object> <!-- closing tags for each parent of the parent object --> </configuration>
We recommend that the application set the default mode to no-change
by including the <default-operation> tag element with the value none, as described
in Setting the Edit Configuration Mode in a NETCONF Session. For more information about leaf
statements with multiple values, see Mapping Configuration Statements to Junos XML Tag Elements.
The following example shows how to remove two of the permissions
granted to the user-accounts login
class:
