RFC 6241
Network Configuration Protocol (NETCONF)
7. Protocol Operations
The NETCONF protocol provides a small set of low-level operations to manage device configurations and retrieve device state information. The base protocol provides operations to retrieve, configure, copy, and delete configuration datastores. Additional operations are provided, based on the capabilities advertised by the device. The base protocol includes the following protocol operations: o get o get-config o edit-config o copy-config o delete-config o lock o unlock o close-session o kill-session A protocol operation can fail for various reasons, including "operation not supported". An initiator SHOULD NOT assume that any operation will always succeed. The return values in any RPC reply SHOULD be checked for error responses. The syntax and XML encoding of the protocol operations are formally defined in the YANG module in Appendix C. The following sections describe the semantics of each protocol operation.7.1. <get-config>
Description: Retrieve all or part of a specified configuration datastore. Parameters: source: Name of the configuration datastore being queried, such as <running/>.
filter: This parameter identifies the portions of the device
configuration datastore to retrieve. If this parameter is not
present, the entire configuration is returned.
The <filter> element MAY optionally contain a "type" attribute.
This attribute indicates the type of filtering syntax used
within the <filter> element. The default filtering mechanism
in NETCONF is referred to as subtree filtering and is described
in Section 6. The value "subtree" explicitly identifies this
type of filtering.
If the NETCONF peer supports the :xpath capability
(Section 8.9), the value "xpath" MAY be used to indicate that
the "select" attribute on the <filter> element contains an
XPath expression.
Positive Response: If the device can satisfy the request, the server
sends an <rpc-reply> element containing a <data> element with the
results of the query.
Negative Response: An <rpc-error> element is included in the
<rpc-reply> if the request cannot be completed for any reason.
Example: To retrieve the entire <users> subtree:
<rpc message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<get-config>
<source>
<running/>
</source>
<filter type="subtree">
<top xmlns="http://example.com/schema/1.2/config">
<users/>
</top>
</filter>
</get-config>
</rpc>
<rpc-reply message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<data>
<top xmlns="http://example.com/schema/1.2/config">
<users>
<user>
<name>root</name>
<type>superuser</type>
<full-name>Charlie Root</full-name>
<company-info>
<dept>1</dept>
<id>1</id>
</company-info>
</user>
<!-- additional <user> elements appear here... -->
</users>
</top>
</data>
</rpc-reply>
Section 6 contains additional examples of subtree filtering.
7.2. <edit-config>
Description:
The <edit-config> operation loads all or part of a specified
configuration to the specified target configuration datastore.
This operation allows the new configuration to be expressed in
several ways, such as using a local file, a remote file, or
inline. If the target configuration datastore does not exist, it
will be created.
If a NETCONF peer supports the :url capability (Section 8.8), the
<url> element can appear instead of the <config> parameter.
The device analyzes the source and target configurations and
performs the requested changes. The target configuration is not
necessarily replaced, as with the <copy-config> message. Instead,
the target configuration is changed in accordance with the
source's data and requested operations.
If the <edit-config> operation contains multiple sub-operations
that apply to the same conceptual node in the underlying data
model, then the result of the operation is undefined (i.e.,
outside the scope of the NETCONF protocol).
Attributes:
operation: Elements in the <config> subtree MAY contain an
"operation" attribute, which belongs to the NETCONF namespace
defined in Section 3.1. The attribute identifies the point in
the configuration to perform the operation and MAY appear on
multiple elements throughout the <config> subtree.
If the "operation" attribute is not specified, the
configuration is merged into the configuration datastore.
The "operation" attribute has one of the following values:
merge: The configuration data identified by the element
containing this attribute is merged with the configuration
at the corresponding level in the configuration datastore
identified by the <target> parameter. This is the default
behavior.
replace: The configuration data identified by the element
containing this attribute replaces any related configuration
in the configuration datastore identified by the <target>
parameter. If no such configuration data exists in the
configuration datastore, it is created. Unlike a
<copy-config> operation, which replaces the entire target
configuration, only the configuration actually present in
the <config> parameter is affected.
create: The configuration data identified by the element
containing this attribute is added to the configuration if
and only if the configuration data does not already exist in
the configuration datastore. If the configuration data
exists, an <rpc-error> element is returned with an
<error-tag> value of "data-exists".
delete: The configuration data identified by the element
containing this attribute is deleted from the configuration
if and only if the configuration data currently exists in
the configuration datastore. If the configuration data does
not exist, an <rpc-error> element is returned with an
<error-tag> value of "data-missing".
remove: The configuration data identified by the element
containing this attribute is deleted from the configuration
if the configuration data currently exists in the
configuration datastore. If the configuration data does not
exist, the "remove" operation is silently ignored by the
server.
Parameters:
target: Name of the configuration datastore being edited, such as
<running/> or <candidate/>.
default-operation: Selects the default operation (as described in
the "operation" attribute) for this <edit-config> request. The
default value for the <default-operation> parameter is "merge".
The <default-operation> parameter is optional, but if provided,
it has one of the following values:
merge: The configuration data in the <config> parameter is
merged with the configuration at the corresponding level in
the target datastore. This is the default behavior.
replace: The configuration data in the <config> parameter
completely replaces the configuration in the target
datastore. This is useful for loading previously saved
configuration data.
none: The target datastore is unaffected by the configuration
in the <config> parameter, unless and until the incoming
configuration data uses the "operation" attribute to request
a different operation. If the configuration in the <config>
parameter contains data for which there is not a
corresponding level in the target datastore, an <rpc-error>
is returned with an <error-tag> value of data-missing.
Using "none" allows operations like "delete" to avoid
unintentionally creating the parent hierarchy of the element
to be deleted.
test-option: The <test-option> element MAY be specified only if
the device advertises the :validate:1.1 capability
(Section 8.6).
The <test-option> element has one of the following values:
test-then-set: Perform a validation test before attempting to
set. If validation errors occur, do not perform the
<edit-config> operation. This is the default test-option.
set: Perform a set without a validation test first.
test-only: Perform only the validation test, without
attempting to set.
error-option: The <error-option> element has one of the following
values:
stop-on-error: Abort the <edit-config> operation on first
error. This is the default error-option.
continue-on-error: Continue to process configuration data on
error; error is recorded, and negative response is generated
if any errors occur.
rollback-on-error: If an error condition occurs such that an
error severity <rpc-error> element is generated, the server
will stop processing the <edit-config> operation and restore
the specified configuration to its complete state at the
start of this <edit-config> operation. This option requires
the server to support the :rollback-on-error capability
described in Section 8.5.
config: A hierarchy of configuration data as defined by one of
the device's data models. The contents MUST be placed in an
appropriate namespace, to allow the device to detect the
appropriate data model, and the contents MUST follow the
constraints of that data model, as defined by its capability
definition. Capabilities are discussed in Section 8.
Positive Response: If the device was able to satisfy the request, an
<rpc-reply> is sent containing an <ok> element.
Negative Response: An <rpc-error> response is sent if the request
cannot be completed for any reason.
Example: The <edit-config> examples in this section utilize a simple
data model, in which multiple instances of the <interface> element
can be present, and an instance is distinguished by the <name>
element within each <interface> element.
Set the MTU to 1500 on an interface named "Ethernet0/0" in the
running configuration:
<rpc message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<edit-config>
<target>
<running/>
</target>
<config>
<top xmlns="http://example.com/schema/1.2/config">
<interface>
<name>Ethernet0/0</name>
<mtu>1500</mtu>
</interface>
</top>
</config>
</edit-config>
</rpc>
<rpc-reply message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<ok/>
</rpc-reply>
Add an interface named "Ethernet0/0" to the running configuration,
replacing any previous interface with that name:
<rpc message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<edit-config>
<target>
<running/>
</target>
<config xmlns:xc="urn:ietf:params:xml:ns:netconf:base:1.0">
<top xmlns="http://example.com/schema/1.2/config">
<interface xc:operation="replace">
<name>Ethernet0/0</name>
<mtu>1500</mtu>
<address>
<name>192.0.2.4</name>
<prefix-length>24</prefix-length>
</address>
</interface>
</top>
</config>
</edit-config>
</rpc>
<rpc-reply message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<ok/>
</rpc-reply>
Delete the configuration for an interface named "Ethernet0/0" from
the running configuration:
<rpc message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<edit-config>
<target>
<running/>
</target>
<default-operation>none</default-operation>
<config xmlns:xc="urn:ietf:params:xml:ns:netconf:base:1.0">
<top xmlns="http://example.com/schema/1.2/config">
<interface xc:operation="delete">
<name>Ethernet0/0</name>
</interface>
</top>
</config>
</edit-config>
</rpc>
<rpc-reply message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<ok/>
</rpc-reply>
Delete interface 192.0.2.4 from an OSPF area (other interfaces
configured in the same area are unaffected):
<rpc message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<edit-config>
<target>
<running/>
</target>
<default-operation>none</default-operation>
<config xmlns:xc="urn:ietf:params:xml:ns:netconf:base:1.0">
<top xmlns="http://example.com/schema/1.2/config">
<protocols>
<ospf>
<area>
<name>0.0.0.0</name>
<interfaces>
<interface xc:operation="delete">
<name>192.0.2.4</name>
</interface>
</interfaces>
</area>
</ospf>
</protocols>
</top>
</config>
</edit-config>
</rpc>
<rpc-reply message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<ok/>
</rpc-reply>
7.3. <copy-config>
Description: Create or replace an entire configuration datastore with the contents of another complete configuration datastore. If the target datastore exists, it is overwritten. Otherwise, a new one is created, if allowed. If a NETCONF peer supports the :url capability (Section 8.8), the <url> element can appear as the <source> or <target> parameter. Even if it advertises the :writable-running capability, a device MAY choose not to support the <running/> configuration datastore as the <target> parameter of a <copy-config> operation. A device MAY choose not to support remote-to-remote copy operations, where both the <source> and <target> parameters use the <url> element. If the <source> and <target> parameters identify the same URL or configuration datastore, an error MUST be returned with an error- tag containing "invalid-value". Parameters: target: Name of the configuration datastore to use as the destination of the <copy-config> operation. source: Name of the configuration datastore to use as the source of the <copy-config> operation, or the <config> element containing the complete configuration to copy. Positive Response: If the device was able to satisfy the request, an <rpc-reply> is sent that includes an <ok> element. Negative Response: An <rpc-error> element is included within the <rpc-reply> if the request cannot be completed for any reason. Example: <rpc message-id="101" xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"> <copy-config> <target> <running/> </target> <source> <url>https://user:password@example.com/cfg/new.txt</url> </source> </copy-config> </rpc>
<rpc-reply message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<ok/>
</rpc-reply>
7.4. <delete-config>
Description: Delete a configuration datastore. The <running>
configuration datastore cannot be deleted.
If a NETCONF peer supports the :url capability (Section 8.8), the
<url> element can appear as the <target> parameter.
Parameters:
target: Name of the configuration datastore to delete.
Positive Response: If the device was able to satisfy the request, an
<rpc-reply> is sent that includes an <ok> element.
Negative Response: An <rpc-error> element is included within the
<rpc-reply> if the request cannot be completed for any reason.
Example:
<rpc message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<delete-config>
<target>
<startup/>
</target>
</delete-config>
</rpc>
<rpc-reply message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<ok/>
</rpc-reply>
7.5. <lock>
Description: The <lock> operation allows the client to lock the
entire configuration datastore system of a device. Such locks are
intended to be short-lived and allow a client to make a change
without fear of interaction with other NETCONF clients, non-
NETCONF clients (e.g., SNMP and command line interface (CLI)
scripts), and human users.
An attempt to lock the configuration datastore MUST fail if an
existing session or other entity holds a lock on any portion of
the lock target.
When the lock is acquired, the server MUST prevent any changes to
the locked resource other than those requested by this session.
SNMP and CLI requests to modify the resource MUST fail with an
appropriate error.
The duration of the lock is defined as beginning when the lock is
acquired and lasting until either the lock is released or the
NETCONF session closes. The session closure can be explicitly
performed by the client, or implicitly performed by the server
based on criteria such as failure of the underlying transport,
simple inactivity timeout, or detection of abusive behavior on the
part of the client. These criteria are dependent on the
implementation and the underlying transport.
The <lock> operation takes a mandatory parameter, <target>. The
<target> parameter names the configuration datastore that will be
locked. When a lock is active, using the <edit-config> operation
on the locked configuration datastore and using the locked
configuration as a target of the <copy-config> operation will be
disallowed by any other NETCONF session. Additionally, the system
will ensure that these locked configuration resources will not be
modified by other non-NETCONF management operations such as SNMP
and CLI. The <kill-session> operation can be used to force the
release of a lock owned by another NETCONF session. It is beyond
the scope of this document to define how to break locks held by
other entities.
A lock MUST NOT be granted if any of the following conditions is
true:
* A lock is already held by any NETCONF session or another
entity.
* The target configuration is <candidate>, it has already been
modified, and these changes have not been committed or rolled
back.
* The target configuration is <running>, and another NETCONF
session has an ongoing confirmed commit (Section 8.4).
The server MUST respond with either an <ok> element or an
<rpc-error>.
A lock will be released by the system if the session holding the
lock is terminated for any reason.
Parameters:
target: Name of the configuration datastore to lock.
Positive Response: If the device was able to satisfy the request, an
<rpc-reply> is sent that contains an <ok> element.
Negative Response: An <rpc-error> element is included in the
<rpc-reply> if the request cannot be completed for any reason.
If the lock is already held, the <error-tag> element will be
"lock-denied" and the <error-info> element will include the
<session-id> of the lock owner. If the lock is held by a non-
NETCONF entity, a <session-id> of 0 (zero) is included. Note that
any other entity performing a lock on even a partial piece of a
target will prevent a NETCONF lock (which is global) from being
obtained on that target.
Example: The following example shows a successful acquisition of a
lock.
<rpc message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<lock>
<target>
<running/>
</target>
</lock>
</rpc>
<rpc-reply message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<ok/> <!-- lock succeeded -->
</rpc-reply>
Example: The following example shows a failed attempt to acquire a
lock when the lock is already in use.
<rpc message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<lock>
<target>
<running/>
</target>
</lock>
</rpc>
<rpc-reply message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<rpc-error> <!-- lock failed -->
<error-type>protocol</error-type>
<error-tag>lock-denied</error-tag>
<error-severity>error</error-severity>
<error-message>
Lock failed, lock is already held
</error-message>
<error-info>
<session-id>454</session-id>
<!-- lock is held by NETCONF session 454 -->
</error-info>
</rpc-error>
</rpc-reply>
7.6. <unlock>
Description: The <unlock> operation is used to release a
configuration lock, previously obtained with the <lock> operation.
An <unlock> operation will not succeed if either of the following
conditions is true:
* The specified lock is not currently active.
* The session issuing the <unlock> operation is not the same
session that obtained the lock.
The server MUST respond with either an <ok> element or an
<rpc-error>.
Parameters:
target: Name of the configuration datastore to unlock.
A NETCONF client is not permitted to unlock a configuration
datastore that it did not lock.
Positive Response: If the device was able to satisfy the request, an
<rpc-reply> is sent that contains an <ok> element.
Negative Response: An <rpc-error> element is included in the
<rpc-reply> if the request cannot be completed for any reason.
Example:
<rpc message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<unlock>
<target>
<running/>
</target>
</unlock>
</rpc>
<rpc-reply message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<ok/>
</rpc-reply>
7.7. <get>
Description: Retrieve running configuration and device state
information.
Parameters:
filter: This parameter specifies the portion of the system
configuration and state data to retrieve. If this parameter is
not present, all the device configuration and state information
is returned.
The <filter> element MAY optionally contain a "type" attribute.
This attribute indicates the type of filtering syntax used
within the <filter> element. The default filtering mechanism
in NETCONF is referred to as subtree filtering and is described
in Section 6. The value "subtree" explicitly identifies this
type of filtering.
If the NETCONF peer supports the :xpath capability
(Section 8.9), the value "xpath" MAY be used to indicate that
the "select" attribute of the <filter> element contains an
XPath expression.
Positive Response: If the device was able to satisfy the request, an
<rpc-reply> is sent. The <data> section contains the appropriate
subset.
Negative Response: An <rpc-error> element is included in the
<rpc-reply> if the request cannot be completed for any reason.
Example:
<rpc message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<get>
<filter type="subtree">
<top xmlns="http://example.com/schema/1.2/stats">
<interfaces>
<interface>
<ifName>eth0</ifName>
</interface>
</interfaces>
</top>
</filter>
</get>
</rpc>
<rpc-reply message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<data>
<top xmlns="http://example.com/schema/1.2/stats">
<interfaces>
<interface>
<ifName>eth0</ifName>
<ifInOctets>45621</ifInOctets>
<ifOutOctets>774344</ifOutOctets>
</interface>
</interfaces>
</top>
</data>
</rpc-reply>
7.8. <close-session>
Description: Request graceful termination of a NETCONF session.
When a NETCONF server receives a <close-session> request, it will
gracefully close the session. The server will release any locks
and resources associated with the session and gracefully close any
associated connections. Any NETCONF requests received after a
<close-session> request will be ignored.
Positive Response: If the device was able to satisfy the request, an
<rpc-reply> is sent that includes an <ok> element.
Negative Response: An <rpc-error> element is included in the
<rpc-reply> if the request cannot be completed for any reason.
Example:
<rpc message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<close-session/>
</rpc>
<rpc-reply message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<ok/>
</rpc-reply>
7.9. <kill-session>
Description: Force the termination of a NETCONF session.
When a NETCONF entity receives a <kill-session> request for an
open session, it will abort any operations currently in process,
release any locks and resources associated with the session, and
close any associated connections.
If a NETCONF server receives a <kill-session> request while
processing a confirmed commit (Section 8.4), it MUST restore the
configuration to its state before the confirmed commit was issued.
Otherwise, the <kill-session> operation does not roll back
configuration or other device state modifications made by the
entity holding the lock.
Parameters:
session-id: Session identifier of the NETCONF session to be
terminated. If this value is equal to the current session ID,
an "invalid-value" error is returned.
Positive Response: If the device was able to satisfy the request, an
<rpc-reply> is sent that includes an <ok> element.
Negative Response: An <rpc-error> element is included in the
<rpc-reply> if the request cannot be completed for any reason.
Example:
<rpc message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<kill-session>
<session-id>4</session-id>
</kill-session>
</rpc>
<rpc-reply message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<ok/>
</rpc-reply>
8. Capabilities
This section defines a set of capabilities that a client or a server
MAY implement. Each peer advertises its capabilities by sending them
during an initial capabilities exchange. Each peer needs to
understand only those capabilities that it might use and MUST ignore
any capability received from the other peer that it does not require
or does not understand.
Additional capabilities can be defined using the template in
Appendix D. Future capability definitions can be published as
standards by standards bodies or published as proprietary extensions.
A NETCONF capability is identified with a URI. The base capabilities
are defined using URNs following the method described in RFC 3553
[RFC3553]. Capabilities defined in this document have the following
format:
urn:ietf:params:netconf:capability:{name}:1.x
where {name} is the name of the capability. Capabilities are often
referenced in discussions and email using the shorthand :{name}, or
:{name}:{version} if the capability exists in multiple versions. For
example, the foo capability would have the formal name
"urn:ietf:params:netconf:capability:foo:1.0" and be called ":foo".
The shorthand form MUST NOT be used inside the protocol.
8.1. Capabilities Exchange
Capabilities are advertised in messages sent by each peer during
session establishment. When the NETCONF session is opened, each peer
(both client and server) MUST send a <hello> element containing a
list of that peer's capabilities. Each peer MUST send at least the
base NETCONF capability, "urn:ietf:params:netconf:base:1.1". A peer
MAY include capabilities for previous NETCONF versions, to indicate
that it supports multiple protocol versions.
Both NETCONF peers MUST verify that the other peer has advertised a
common protocol version. When comparing protocol version capability
URIs, only the base part is used, in the event any parameters are
encoded at the end of the URI string. If no protocol version
capability in common is found, the NETCONF peer MUST NOT continue the
session. If more than one protocol version URI in common is present,
then the highest numbered (most recent) protocol version MUST be used
by both peers.
A server sending the <hello> element MUST include a <session-id>
element containing the session ID for this NETCONF session. A client
sending the <hello> element MUST NOT include a <session-id> element.
A server receiving a <hello> message with a <session-id> element MUST
terminate the NETCONF session. Similarly, a client that does not
receive a <session-id> element in the server's <hello> message MUST
terminate the NETCONF session (without first sending a
<close-session>).
In the following example, a server advertises the base NETCONF
capability, one NETCONF capability defined in the base NETCONF
document, and one implementation-specific capability.
<hello xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<capabilities>
<capability>
urn:ietf:params:netconf:base:1.1
</capability>
<capability>
urn:ietf:params:netconf:capability:startup:1.0
</capability>
<capability>
http://example.net/router/2.3/myfeature
</capability>
</capabilities>
<session-id>4</session-id>
</hello>
Each peer sends its <hello> element simultaneously as soon as the
connection is open. A peer MUST NOT wait to receive the capability
set from the other side before sending its own set.
8.2. Writable-Running Capability
8.2.1. Description
The :writable-running capability indicates that the device supports direct writes to the <running> configuration datastore. In other words, the device supports <edit-config> and <copy-config> operations where the <running> configuration is the target.8.2.2. Dependencies
None.8.2.3. Capability Identifier
The :writable-running capability is identified by the following capability string: urn:ietf:params:netconf:capability:writable-running:1.08.2.4. New Operations
None.8.2.5. Modifications to Existing Operations
8.2.5.1. <edit-config>
The :writable-running capability modifies the <edit-config> operation to accept the <running> element as a <target>.8.2.5.2. <copy-config>
The :writable-running capability modifies the <copy-config> operation to accept the <running> element as a <target>.8.3. Candidate Configuration Capability
8.3.1. Description
The candidate configuration capability, :candidate, indicates that the device supports a candidate configuration datastore, which is used to hold configuration data that can be manipulated without impacting the device's current configuration. The candidate configuration is a full configuration data set that serves as a work place for creating and manipulating configuration data. Additions, deletions, and changes can be made to this data to construct the
desired configuration data. A <commit> operation MAY be performed at any time that causes the device's running configuration to be set to the value of the candidate configuration. The <commit> operation effectively sets the running configuration to the current contents of the candidate configuration. While it could be modeled as a simple copy, it is done as a distinct operation for a number of reasons. In keeping high-level concepts as first-class operations, we allow developers to see more clearly both what the client is requesting and what the server must perform. This keeps the intentions more obvious, the special cases less complex, and the interactions between operations more straightforward. For example, the :confirmed-commit:1.1 capability (Section 8.4) would make no sense as a "copy confirmed" operation. The candidate configuration can be shared among multiple sessions. Unless a client has specific information that the candidate configuration is not shared, it MUST assume that other sessions are able to modify the candidate configuration at the same time. It is therefore prudent for a client to lock the candidate configuration before modifying it. The client can discard any uncommitted changes to the candidate configuration by executing the <discard-changes> operation. This operation reverts the contents of the candidate configuration to the contents of the running configuration.8.3.2. Dependencies
None.8.3.3. Capability Identifier
The :candidate capability is identified by the following capability string: urn:ietf:params:netconf:capability:candidate:1.08.3.4. New Operations
8.3.4.1. <commit>
Description: When the candidate configuration's content is complete, the configuration data can be committed, publishing the data set to the rest of the device and requesting the device to conform to the behavior described in the new configuration.
To commit the candidate configuration as the device's new
current configuration, use the <commit> operation.
The <commit> operation instructs the device to implement the
configuration data contained in the candidate configuration.
If the device is unable to commit all of the changes in the
candidate configuration datastore, then the running
configuration MUST remain unchanged. If the device does
succeed in committing, the running configuration MUST be
updated with the contents of the candidate configuration.
If the running or candidate configuration is currently locked
by a different session, the <commit> operation MUST fail with
an <error-tag> value of "in-use".
If the system does not have the :candidate capability, the
<commit> operation is not available.
Positive Response:
If the device was able to satisfy the request, an <rpc-reply>
is sent that contains an <ok> element.
Negative Response:
An <rpc-error> element is included in the <rpc-reply> if the
request cannot be completed for any reason.
Example:
<rpc message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<commit/>
</rpc>
<rpc-reply message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<ok/>
</rpc-reply>
8.3.4.2. <discard-changes>
If the client decides that the candidate configuration is not to be
committed, the <discard-changes> operation can be used to revert the
candidate configuration to the current running configuration.
<rpc message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<discard-changes/>
</rpc>
This operation discards any uncommitted changes by resetting the
candidate configuration with the content of the running
configuration.
8.3.5. Modifications to Existing Operations
8.3.5.1. <get-config>, <edit-config>, <copy-config>, and <validate>
The candidate configuration can be used as a source or target of any
<get-config>, <edit-config>, <copy-config>, or <validate> operation
as a <source> or <target> parameter. The <candidate> element is used
to indicate the candidate configuration:
<rpc message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<get-config>
<source>
<candidate/>
</source>
</get-config>
</rpc>
8.3.5.2. <lock> and <unlock>
The candidate configuration can be locked using the <lock> operation
with the <candidate> element as the <target> parameter:
<rpc message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<lock>
<target>
<candidate/>
</target>
</lock>
</rpc>
Similarly, the candidate configuration is unlocked using the
<candidate> element as the <target> parameter:
<rpc message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<unlock>
<target>
<candidate/>
</target>
</unlock>
</rpc>
When a client fails with outstanding changes to the candidate
configuration, recovery can be difficult. To facilitate easy
recovery, any outstanding changes are discarded when the lock is
released, whether explicitly with the <unlock> operation or
implicitly from session failure.
8.4. Confirmed Commit Capability
8.4.1. Description
The :confirmed-commit:1.1 capability indicates that the server will
support the <cancel-commit> operation and the <confirmed>,
<confirm-timeout>, <persist>, and <persist-id> parameters for the
<commit> operation. See Section 8.3 for further details on the
<commit> operation.
A confirmed <commit> operation MUST be reverted if a confirming
commit is not issued within the timeout period (by default 600
seconds = 10 minutes). The confirming commit is a <commit> operation
without the <confirmed> parameter. The timeout period can be
adjusted with the <confirm-timeout> parameter. If a follow-up
confirmed <commit> operation is issued before the timer expires, the
timer is reset to the new value (600 seconds by default). Both the
confirming commit and a follow-up confirmed <commit> operation MAY
introduce additional changes to the configuration.
If the <persist> element is not given in the confirmed commit
operation, any follow-up commit and the confirming commit MUST be
issued on the same session that issued the confirmed commit. If the
<persist> element is given in the confirmed <commit> operation, a
follow-up commit and the confirming commit can be given on any
session, and they MUST include a <persist-id> element with a value
equal to the given value of the <persist> element.
If the server also advertises the :startup capability, a
<copy-config> from running to startup is also necessary to save the
changes to startup.
If the session issuing the confirmed commit is terminated for any reason before the confirm timeout expires, the server MUST restore the configuration to its state before the confirmed commit was issued, unless the confirmed commit also included a <persist> element. If the device reboots for any reason before the confirm timeout expires, the server MUST restore the configuration to its state before the confirmed commit was issued. If a confirming commit is not issued, the device will revert its configuration to the state prior to the issuance of the confirmed commit. To cancel a confirmed commit and revert changes without waiting for the confirm timeout to expire, the client can explicitly restore the configuration to its state before the confirmed commit was issued, by using the <cancel-commit> operation. For shared configurations, this feature can cause other configuration changes (for example, via other NETCONF sessions) to be inadvertently altered or removed, unless the configuration locking feature is used (in other words, the lock is obtained before the <edit-config> operation is started). Therefore, it is strongly suggested that in order to use this feature with shared configuration datastores, configuration locking SHOULD also be used. Version 1.0 of this capability was defined in [RFC4741]. Version 1.1 is defined in this document, and extends version 1.0 by adding a new operation, <cancel-commit>, and two new optional parameters, <persist> and <persist-id>. For backwards compatibility with old clients, servers conforming to this specification MAY advertise version 1.0 in addition to version 1.1.8.4.2. Dependencies
The :confirmed-commit:1.1 capability is only relevant if the :candidate capability is also supported.8.4.3. Capability Identifier
The :confirmed-commit:1.1 capability is identified by the following capability string: urn:ietf:params:netconf:capability:confirmed-commit:1.1
8.4.4. New Operations
8.4.4.1. <cancel-commit>
Description: Cancels an ongoing confirmed commit. If the <persist-id> parameter is not given, the <cancel-commit> operation MUST be issued on the same session that issued the confirmed commit. Parameters: persist-id: Cancels a persistent confirmed commit. The value MUST be equal to the value given in the <persist> parameter to the <commit> operation. If the value does not match, the operation fails with an "invalid-value" error. Positive Response: If the device was able to satisfy the request, an <rpc-reply> is sent that contains an <ok> element. Negative Response: An <rpc-error> element is included in the <rpc-reply> if the request cannot be completed for any reason. Example: <rpc message-id="101" xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"> <commit> <confirmed/> </commit> </rpc> <rpc-reply message-id="101" xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"> <ok/> </rpc-reply> <rpc message-id="102" xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"> <cancel-commit/> </rpc>
<rpc-reply message-id="102"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<ok/>
</rpc-reply>
8.4.5. Modifications to Existing Operations
8.4.5.1. <commit>
The :confirmed-commit:1.1 capability allows 4 additional parameters
to the <commit> operation.
Parameters:
confirmed:
Perform a confirmed <commit> operation.
confirm-timeout:
Timeout period for confirmed commit, in seconds. If
unspecified, the confirm timeout defaults to 600 seconds.
persist:
Make the confirmed commit survive a session termination, and
set a token on the ongoing confirmed commit.
persist-id:
Used to issue a follow-up confirmed commit or a confirming
commit from any session, with the token from the previous
<commit> operation.
Example:
<rpc message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<commit>
<confirmed/>
<confirm-timeout>120</confirm-timeout>
</commit>
</rpc>
<rpc-reply message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<ok/>
</rpc-reply>
Example:
<!-- start a persistent confirmed-commit -->
<rpc message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<commit>
<confirmed/>
<persist>IQ,d4668</persist>
</commit>
</rpc>
<rpc-reply message-id="101"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<ok/>
</rpc-reply>
<!-- confirm the persistent confirmed-commit,
possibly from another session -->
<rpc message-id="102"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<commit>
<persist-id>IQ,d4668</persist-id>
</commit>
</rpc>
<rpc-reply message-id="102"
xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<ok/>
</rpc-reply>
(page 61 continued on part 4)
