Enhancements to Data Models

This section provides an overview of the enhancements made to data models.

Improved YANG Input Validator and Get Requests

Table 1. Feature History Table

Feature Name

Release Information

Description

Improved YANG Input Validator and Get Requests

Release 7.10.1

The OpenConfig data models provide a structure for managing networks via YANG protocols. With this release, enhancements to the configuration architecture improve input validations and ensure that the Get requests made through gNMI or NETCONF protocols return only explicitly configured OpenConfig leaves.

Previously, Get requests returned all the items in the Cisco native data models that the system could convert into OpenConfig items, regardless of whether they were initially configured via OpenConfig. We have added a new legacy mode option for a limited number of releases which helps you preserve this behaviour.

In IOS XR Software Release 7.10.1, the following are the enhancements to improve YANG Input Validator and Get Requests:

  • Get requests made via NETCONF or gNMI now return only OpenConfig leaves that were configured using OpenConfig models.

    Use the legacy mode as follows:

    NETCONF: Add a legacy mode attribute to the get-config request tag,

    Example: get-config xmlns:xr-md=”http://cisco.com/ns/yang/cisco-xr-metadata” xr-md:mode="legacy"

    gNMI: Set the origin to openconfig-legacy .

  • Improved input validation for OpenConfig configurations to provide a more consistent experience across the schema.

    The new validation includes enhanced error reporting, though some errors may include references to XR configuration schema paths and item values in the message string.

  • OpenConfig leaves now return default values consistently.

    Get requests use the Explicit Basic Mode (refer RFC6243) to return only the OpenConfig leaves that were explicitly configured.

Usage Guidelines and Limitations

In this release, the following usage guidelines and limitations apply based on the following functionalities:

  • Upgrades to Cisco IOS XR Software Release 7.10.1 and later will not show OpenConfig leaves in Get requests until OpenConfig has been successfully committed.

  • Similarly, downgrading from Release 7.10.1 to an earlier version and then upgrading back to Release 7.10.1 will not show OpenConfig leaves in Get requests until OpenConfig has been successfully committed.

  • Each feature must be fully configured using OpenConfig or Cisco native data model or CLI.

    If configuration items applied to a feature via OpenConfig are overridden by configuring those items directly via Cisco native data model, this will not be reflected in the system view of currently configured OpenConfig items.

    Use the Cisco native data model to configure features not supported by OpenConfig data model.

  • Use either gNMI or NETCONF to manage configuration via OpenConfig. We recommend not to use both the management agents on the same device simultaneously.

    Once a successful commit has been made using gNMI or NETCONF, that management agent is considered the active agent.

    OpenConfig items cannot be configured by the non-active agent. However, the non-active agent can configure Cisco native data model items and perform Get requests on any configuration items.

    All OpenConfig leaves must first be removed by the active agent before a different agent can be used.

  • During the commit process (which can take many minutes for large changesets), Get requests can be made on the running datastore.

    Other request types like, Edit request, Commit request from other clients, and Get request on the candidate datastore of another client are rejected.

  • When ACLs are configured via OpenConfig, CLI actions such as resequencing ACLs and copying ACLs will not be reflected in the system view of the current OpenConfig configuration.

  • Configuration modifications made by Config Scripts to features configured through OpenConfig will not be reflected in the system view of the current OpenConfig configuration which is returned from Get-config operations.

  • Configuration removal from the system may occur as a result of some events, such as install operations and startup configuration failures during line card insertion.

    OpenConfig items currently configured do not reflect this change. In such cases, a syslog will be generated to remind the user to manually apply OpenConfig configurations to the system.

  • All OpenConfig will be removed from the system when a Commit Replace operation is performed using the CLI.

  • By using the show running-config | (xml | json) openconfig command, you can still view the running OpenConfig. However, you cannot filter the view using XR CLI configuration keywords.

  • The load rollback changes and load commit changes commands are not supported for rollback or commit that include OpenConfig leaves.

OpenConfig Data Model Enhancements

Table 2. Feature History Table

Feature Name

Release Information

Description

Revised OpenConfig MPLS Model to Version 3.0.1 for Streaming Telemetry

Release 7.3.3

The OpenConfig MPLS data model provides data definitions for Multiprotocol Label Switching (MPLS) configuration and associated signaling and traffic engineering protocols. In this release, the following data models are revised for streaming telemetry from OpenConfig version 2.3.0 to version 3.0.1:

  • openconfig-mpls

  • openconfig-mpls-te

  • openconfig-mpls-rsvp

  • openconfig-mpls-igp

  • openconfig-mpls-types

  • openconfig-mpls-sr

You can access this data model from the Github repository.

OAM for MPLS and SR-MPLS in mpls-ping and mpls-traceroute Data Models

Table 3. Feature History Table

Feature Name

Release Information

Description

YANG Data Models for MPLS OAM RPCs

Release 7.3.2

This feature introduces the Cisco-IOS-XR-mpls-ping-act and Cisco-IOS-XR-mpls-traceroute-act YANG data models to accommodate operations, administration and maintenance (OAM) RPCs for MPLS and SR-MPLS.

You can access these Cisco IOS XR native data models from the Github repository.

The Cisco-IOS-XR-mpls-ping-act and Cisco-IOS-XR-mpls-traceroute-act YANG data models are introduced to provide the following options:

  • Ping for MPLS:

    • MPLS IPv4 address

    • MPLS TE

    • FEC-129 Pseudowire

    • FEC-128 Pseudowire

    • Multisegment Pseudowire

  • Ping for SR-MPLS:

    • SR policy name or BSID with LSP end-point

    • SR MPLS IPv4 address

    • SR Nil-FEC labels

    • SR Flexible Algorithm

  • Traceroute for MPLS:

    • MPLS IPv4 address

    • MPLS TE

  • Traceroute for SR-MPLS:

    • SR policy name or BSID with LSP end-point

    • SR MPLS IPv4 address

    • SR Nil-FEC labels

    • SR Flexible Algorithm

The following example shows the ping operation for an SR policy and LSP end-point:

<mpls-ping xmlns="http://cisco.com/ns/yang/Cisco-IOS-XR-mpls-ping-act">
  <sr-mpls>
  <policy>
    <name>srte_c_10_ep_10.10.10.1</name>
      <lsp-endpoint>10.10.10.4</lsp-endpoint>
  </policy>
  </sr-mpls>
  <request-options-parameters>
    <brief>true</brief>
  </request-options-parameters>
</mpls-ping>

Response:

<?xml version="1.0"?>
 <mpls-ping-response xmlns="http://cisco.com/ns/yang/Cisco-IOS-XR-mpls-ping-act">
  <request-options-parameters>
   <exp>0</exp>
   <fec>false</fec>
   <interval>0</interval>
   <ddmap>false</ddmap>
   <force-explicit-null>false</force-explicit-null>
   <packet-output>
    <interface-name>None</interface-name>
    <next-hop>0.0.0.0</next-hop>
   </packet-output>
   <pad>abcd</pad>
   <repeat>5</repeat>
   <reply>
    <dscp>255</dscp>
    <reply-mode>default</reply-mode>
    <pad-tlv>false</pad-tlv>
   </reply>
   <size>100</size>
   <source>0.0.0.0</source>
   <destination>127.0.0.1</destination>
   <sweep>
    <minimum>100</minimum>
    <maximum>100</maximum>
    <increment>1</increment>
   </sweep>
   <brief>true</brief>
   <timeout>2</timeout>
   <ttl>255</ttl>
  </request-options-parameters>
  <replies>
   <reply>
    <reply-index>1</reply-index>
    <return-code>3</return-code>
    <return-char>!</return-char>
    <reply-addr>14.14.14.3</reply-addr>
    <size>100</size>
   </reply>
   <reply>
    <reply-index>2</reply-index>
    <return-code>3</return-code>
    <return-char>!</return-char>
    <reply-addr>14.14.14.3</reply-addr>
    <size>100</size>
   </reply>
   <reply>
    <reply-index>3</reply-index>
    <return-code>3</return-code>
    <return-char>!</return-char>
    <reply-addr>14.14.14.3</reply-addr>
    <size>100</size>
   </reply>
   <reply>
    <reply-index>4</reply-index>
    <return-code>3</return-code>
    <return-char>!</return-char>
    <reply-addr>14.14.14.3</reply-addr>
    <size>100</size>
   </reply>
   <reply>
    <reply-index>5</reply-index>
    <return-code>3</return-code>
    <return-char>!</return-char>
    <reply-addr>14.14.14.3</reply-addr>
    <size>100</size>
   </reply>
  </replies>
 </mpls-ping-response>

The following example shows the ping operation for an SR policy BSID and LSP end-point:

<mpls-ping xmlns="http://cisco.com/ns/yang/Cisco-IOS-XR-mpls-ping-act">
<sr-mpls>
<policy>
    <bsid>1000</bsid>
    <lsp-endpoint>10.10.10.4</lsp-endpoint>
</policy>
</sr-mpls>
<request-options-parameters>
    <brief>true</brief>
</request-options-parameters>
</mpls-ping>

Response:

<?xml version="1.0"?>
 <mpls-ping-response xmlns="http://cisco.com/ns/yang/Cisco-IOS-XR-mpls-ping-act">
  <request-options-parameters>
   <exp>0</exp>
   <fec>false</fec>
   <interval>0</interval>
   <ddmap>false</ddmap>
   <force-explicit-null>false</force-explicit-null>
   <packet-output>
    <interface-name>None</interface-name>
    <next-hop>0.0.0.0</next-hop>
   </packet-output>
   <pad>abcd</pad>
   <repeat>5</repeat>
   <reply>
    <dscp>255</dscp>
    <reply-mode>default</reply-mode>
    <pad-tlv>false</pad-tlv>
   </reply>
   <size>100</size>
   <source>0.0.0.0</source>
   <destination>127.0.0.1</destination>
   <sweep>
    <minimum>100</minimum>
    <maximum>100</maximum>
    <increment>1</increment>
   </sweep>
   <brief>true</brief>
   <timeout>2</timeout>
   <ttl>255</ttl>
  </request-options-parameters>
  <replies>
   <reply>
    <reply-index>1</reply-index>
    <return-code>3</return-code>
    <return-char>!</return-char>
    <reply-addr>14.14.14.3</reply-addr>
    <size>100</size>
   </reply>
   <reply>
    <reply-index>2</reply-index>
    <return-code>3</return-code>
    <return-char>!</return-char>
    <reply-addr>14.14.14.3</reply-addr>
    <size>100</size>
   </reply>
   <reply>
    <reply-index>3</reply-index>
    <return-code>3</return-code>
    <return-char>!</return-char>
    <reply-addr>14.14.14.3</reply-addr>
    <size>100</size>
   </reply>
   <reply>
    <reply-index>4</reply-index>
    <return-code>3</return-code>
    <return-char>!</return-char>
    <reply-addr>14.14.14.3</reply-addr>
    <size>100</size>
   </reply>
   <reply>
    <reply-index>5</reply-index>
    <return-code>3</return-code>
    <return-char>!</return-char>
    <reply-addr>14.14.14.3</reply-addr>
    <size>100</size>
   </reply>
  </replies>
 </mpls-ping-response>

The following example shows the traceroute operation for an SR policy and LSP end-point:

<mpls-traceroute xmlns="http://cisco.com/ns/yang/Cisco-IOS-XR-mpls-traceroute-act">
<sr-mpls>
<policy>
    <name>srte_c_10_ep_10.10.10.1</name>
    <lsp-endpoint>10.10.10.4</lsp-endpoint>
</policy>
</sr-mpls>
<request-options-parameters>
    <brief>true</brief>
</request-options-parameters>
</mpls-traceroute>

Response:

<?xml version="1.0"?>
 <mpls-traceroute-response xmlns="http://cisco.com/ns/yang/Cisco-IOS-XR-mpls-traceroute-act">
  <request-options-parameters>
   <exp>0</exp>
   <fec>false</fec>
   <ddmap>false</ddmap>
   <force-explicit-null>false</force-explicit-null>
   <packet-output>
    <interface-name>None</interface-name>
    <next-hop>0.0.0.0</next-hop>
   </packet-output>
   <reply>
    <dscp>255</dscp>
    <reply-mode>default</reply-mode>
   </reply>
   <source>0.0.0.0</source>
   <destination>127.0.0.1</destination>
   <brief>true</brief>
   <timeout>2</timeout>
   <ttl>30</ttl>
  </request-options-parameters>
  <paths>
   <path>
    <path-index>0</path-index>
    <hops>
    <hop>
        <hop-index>0</hop-index>
        <hop-origin-ip>11.11.11.1</hop-origin-ip>
        <hop-destination-ip>11.11.11.2</hop-destination-ip>
        <mtu>1500</mtu>
        <dsmap-label-stack>
            <dsmap-label>
                <label>16003</label>
            </dsmap-label>
        </dsmap-label-stack>
        <return-code>0</return-code>
        <return-char> </return-char>
    </hop>
    <hop>
        <hop-index>1</hop-index>
        <hop-origin-ip>11.11.11.2</hop-origin-ip>
        <hop-destination-ip>14.14.14.3</hop-destination-ip>
        <mtu>1500</mtu>
        <dsmap-label-stack>
            <dsmap-label>
                <label>3</label>
            </dsmap-label>
        </dsmap-label-stack>
        <return-code>8</return-code>
        <return-char>L</return-char>
    </hop>
    <hop>
        <hop-index>2</hop-index>
        <hop-origin-ip>14.14.14.3</hop-origin-ip>
        <hop-destination-ip></hop-destination-ip>
        <mtu>0</mtu>
        <dsmap-label-stack/>
        <return-code>3</return-code>
        <return-char>!</return-char>
    </hop>
    </hops>
   </path>
  </paths>
  </mpls-traceroute-response>

Automatic Resynchronization of OpenConfig Configuration

Table 4. Feature History Table

Feature Name

Release Information

Feature Description

Automatic Resynchronization of OpenConfig Configuration

Release 7.11.1

OpenConfig infrastructure can now reapply all the OpenConfig configurations automatically if there are any discrepancies in the running configuration.

With this feature, there is no need for manual replacement of the OpenConfig configuration using Netconf or gNMI.

The re-sync operation is triggered if the running configurations and the OpenConfig configuration go out of sync after any system event that removes some running configurations from the system. A corresponding system log gets generated to indicate the re-sync status.

In the earlier releases, when activities such as interface breakout operations, installation activities or insertion of a new line card took place, there was a risk of OpenConfig configuration and the running configuration going out of sync. A full replacement of the OpenConfig configuration was required in order to get the OpenConfig configurations back in sync using Netconf or gNMI.

From the Cisco IOS XR Software Release 7.11.1, if the OpenConfig configurations and running configurations go out of sync, or any activities takes place which may result in the two configurations to go out of sync, the system automatically reapplies all the OpenConfig configurations and resolve the sync issue. If there is a synchronization issue between the running configuration and the OpenConfig configuration, a corresponding system log is generated to indicate it. Similarly, a corresponding system log is generated indicating the status of the re-synchronization attempt.

This feature is enabled by default. This process is completely automated.

Operations that Remove Running Configuration

Here are three types of operation that can have the effect of removing running configuration from the system. Running configurations are either affected because they directly remove configuration in the system or because they result in configuration failing to be accepted by the system during start-up.

  • Install operations: Running configuration can be removed during non-reload and reload install operations. During non-reload install, running configuration is removed when it is incompatible with the new software. In this case, it is directly removed by the Install infra. The configuration is removed during reload install operations if the attempt to restore the startup configuration is partially successful.

  • Breakout interfaces configuration: When breakout interfaces are configured or de-configured, all the existing configuration on interfaces is affected. The affect may be creation or deletion of the parent and child interfaces. This results in an inconsistency between the running configuration and the OpenConfig datastore for any of the removed configurations that was mapped from OpenConfig configuration.

    The automatic restoration of OpenConfig configuration resolves this inconsistency by re-adding that removed configuration.

  • New line card insertion: On insertion of a new line card into the system, any pre-configuration for that card is verified for the first time and may be rejected, causing it to be removed. This results in an inconsistency between the running configuration and the OpenConfig datastore.

In any of the above scenarios, if there is a sync issue, system logs are generated and the system tries to reapply all the OpenConfig configurations. If the re-sync attempt is successful, the configurations which were removed earlier, are re-applied. If the re-sync attempt fails, this means that some of the OpenConfig configuration is no longer valid.


Note

The above scenarios are invalid if there are no OpenConfig configuration present in the system.

System Logs Indicating Out-of-Sync Configuration

System log messages are generated due to the above operations that can lead to discrepancies in configurations on the router. Listed are examples of system log messages raised if any such discrepancies occur.

Table 5. Examples of system log messages generated due to Out-of-Sync Configurations :

Event Name Displayed in the System Log

Description
unexpected commit errors

When an unexpected commit errors in case of a SysDB server crash.

config rollback (to a commit ID created using a different software version)

When a configuration rollbacks back to a commit ID created using a different software version.

inconsistent configuration

This system log is generated when an inconsistency alarm is raised due to failure in restoring the start-up configurations after activities like system reload or insertion of a new line card. Re-synchronization of the configuration is triggered only after the alarm is cleared.

configuration removal (triggered on 0/2/CPU0 by the last config operation for interface GigabitEthernet0/2/0/0 and 6 other interfaces)

When interface configuration is removed in response to a change in interface breakout configuration.
configuration removal (to prepare for an install operation)

Configuration is removed from the system during a non-reload install operation due to incompatibility with the new software.

Alarms Related to Out-of-Sync OpenConfig Configuration

  • Inconsistency alarm: When a there is a failure in restoring the start-up configurations after a system reload or insertion of a new line card, inconsistency alarm is raised. If the inconsistency alarm is raised, you can see an informational system log is generated which indicates that the OpenConfig configuration and running configuration may be out of sync. A re-sync attempt will be made when the configuration inconsistency alarm is cleared. This system log is an early warning that the system is potentially out of sync.

    Inconsistency alarm message:

    NMI OpenConfig configuration is potentially out of sync with the running configuration (details: system configuration become inconsistent during OIR restore on 0/0/CPU0). An automatic reapply of the OpenConfig configuration will be performed when the inconsistency alarm is cleared.

  • Missing item in the OpenConfig datastore alarm: If there are missing items in the configurations which could not be added to the OpenConfig datastore while loading in a snapshot from disk, you can see an error system log is raised which indicates that there are some items which are absent in the running OpenConfig configuration. This scenario occurs when the yang schema is changed from the time the snapshot was created.

    Item missing alarm message:

    gNMI OpenConfig configuration is potentially out of sync with the running configuration: 3 failed to be applied to the system (details: snapshot 2 was created with a different schema version). The system may contain config items mapped from OC that no longer exist in the OC datastore. Automatic attempts to reapply OC will not remove these items, even if they otherwise succeed. Config should be replaced manually using a GNMI Replace operation.

System Logs Generated During Configuration Resynchronization:

When an attempt to re-apply OpenConfig (resynchronization) is complete, the following informational system logs are generated to indicate the user that the OpenConfig and running configuration were out of sync, and whether the attempt to resolve this was successful.

  • Successful re-sync:

    As a result of configuration removal (to prepare for an install operation), the gNMI OpenConfig configuration has been successfully reapplied.

  • Unsuccessful re-sync:

    As a result of configuration removal (to prepare for an install operation), an attempt to reapply the gNMI configuration was made, but some items remain out of sync with the running configuration. The configuration should be reapplied manually using a GNMI Replace operation.

  • Re-sync failure during mapping of OpenConfig configurations to XR configurations:

    As a result of configuration removal (to prepare for an install operation), the attempt to reapply the gNMI OpenConfig configuration failed, and the out of sync configuration could not be updated. gNMI OpenConfig configuration is potentially out of sync with the running configuration. Configuration should be reapplied manually using a GNMI Replace operation

Re-sync failure during mapping of OpenConfig configurations to XR configurations is a rare scenario. When there is a failure in the re-sync process while mapping the OpenConfig configuration to XR items, it causes the re-sync request to aborted. This scenario is only possible after an install which changes the OpenConfig mappings such that some configuration is no longer supported.