Release Notes for Cisco Resilient Mesh Release 6.4

These release notes contain the latest information about using Cisco Resilient Mesh (CR-Mesh, formerly known as CG-Mesh) with IPv6 Resilient Mesh Endpoints (RMEs) such as meters and the Cisco IR500 Series WPAN Gateway Range Extenders.


The documentation set for this product strives to use bias-free language. For purposes of this documentation set, bias-free is defined as language that does not imply discrimination based on age, disability, gender, racial identity, ethnic identity, sexual orientation, socioeconomic status, and intersectionality. Exceptions may be present in the documentation due to language that is hardcoded in the user interfaces of the product software, language used based on RFP documentation, or language that is used by a referenced third-party product.

Cisco Resilient Mesh is an embedded network stack for Smart Grid assets within a Neighborhood Area Network. Cisco Resilient Mesh provides end-to-end IPv6 communication and implements open-standard protocols at every layer in the network stack, including but not limited to IEEE 802.15.4e/g, 6LoWPAN, IPv6, RPL, UDP, and CoAP. In Smart Grid assets such as residential electric meters, the Cisco Resilient Mesh software functions within a dedicated Communications Module that connects to an Application Module through a PPP link.

From CR-Mesh Release 6.3, only Wi-SUN protocol stack is supported. In CR-Mesh Release 5.6, classic CR-Mesh protocol stack is supported. CR-Mesh Release 6.1 and 6.2 support both Wi-SUN and classic CR-Mesh stack, from which you can use the configuration option "stack mode" to choose CR-Mesh or Wi-SUN mode.


IR529 is no longer supported for CR-Mesh Release 6.4 and later releases.


For a detailed description of the Cisco Resilient Mesh software in Release 6.4, refer to Cisco Connected Grid WPAN Module for CGR 1000 Series Installation and Cisco Resilient Mesh Configuration Guide.

New Features for This Release

The following table lists the enhancements specific to this release.

Table 1. Enhancements for Cisco Resilient Mesh Release 6.4




All platforms

CSMP Source Code availability in C code

CSMP code to be avilable in a standard dialect of C along with documentation on how to integrate the code with a third party Wi-SUN stack (non Cisco/L+G)



Performance enhancement on IR510 platform

Improvement of IR510 mesh network bandwidth.







Debugging capabilities within the CR mesh endpoint

FND supports to showcase the state changes and the troubleshooting data offered by the endpoint.




Wi-SUN 1.1 update

Adaptive rate, adaptive modulation, and Phy modes update to match the Wi-SUN 1.1 spec.









Features carried over from CG-Mesh stack to Wi-SUN stack: RPL Enhancements, and L2 heartbeats

Features carried over from CG-Mesh code:

  • RPL metric container: dag_size, etx, hop_count for more information of the topology—Include more RPL metrics in the DAO upstream message to help FND showcase more meaningful information and display the data on the google map as well as the device page.

    The following commands on CGR configure whether BR’s DIO carries DAG Metric Container option and the private flag of DODAG configuration option.

    • rpl option metric-container—Include metric option in DIO message in Wi-SUN mode core instance. no rpl option metric-container is used to disable this configuration.

    • rpl option dodag-config cisco-flag <0-1>—Set Cisco flag to a value between 0 and 1 in DODAG configuration option in Wi-SUN mode core instance.

  • Layer 2 heartbeats—Detect CGR failure more effectively and improve PAN migration time.




Provide visibility to track the status of the app image transferred from the comm module to the app module

Track the workflow for downloading the App image from the comm module to the app module.

When the Comm module receives the app image from FND, a new index in TLV75 is defined to ensure that the App module has successfully pulled the image from the comm modules. Added loaderrorcode field to index 2 of TLV75 to track the status of the App image transferred.

System Requirements

If you plan to run Cisco Resilient Mesh Release 6.4, you must have the following required hardware and software components:


Minimum Cisco IOS Software Release Required

Cisco 1000 Series Connected Grid Router

Cisco IOS Release 15.9(3)M4 or later

Cisco Catalyst IR8100 Heavy Duty Series Routers

Cisco IOS-XE Release 17.6.1 or later

Cisco IR530


Cisco IR510






IoT Field Network Director

Release 4.7.1-60 or later


Supported Software Features

This section covers the supported software features.

Compromised Node Eviction

A compromised node is one where the device can no longer be trusted by the network and/or operators. Nodes within an IEEE 802.15.4 PAN must possess the currently valid Group Temporal Key (GTK) to send and receive link-layer messages. The GTK is shared among all devices within the PAN and is refreshed periodically or on-demand. By communicating new GTKs to only trusted devices, compromised nodes may be evicted from the network.


In its route-over architecture, Cisco Resilient Mesh performs routing at the network layer using the Routing Protocol for Low-Power and Lossy Networks (RPL).

Cisco Resilient Mesh requires a Cisco 1000 Series Connected Grid Router (CGR) to provide connectivity to other IPv6 networks. The CGR (Field Area Router (FAR)) must serve as a RPL Directed Acyclic Graph (DAG) root and store information reported in DAO messages to forward datagrams to individual nodes within the mesh network.


The 6LoWPAN adaptation layer adapts IPv6 to operate efficiently over low-power and lossy links such as IEEE 802.15.4. The adaptation layer sits between the IPv6 and IEEE 802.15.4 layers and provides IPv6 header compression, IPv6 datagram fragmentation, and optimized IPv6 Neighbor Discovery.

Frequency Hopping

Cisco Resilient Mesh implements frequency hopping across 64 channels with 400-kHz spacing in the 902 to 928 MHz ISM band. The frequency-hopping protocol used by Cisco Resilient Mesh maximizes the use of the available spectrum by allowing multiple sender-receiver pairs to communicate simultaneously on different channels. The frequency hopping protocol also mitigates the negative effects of narrowband interferers.


For IR510 and IR530 endpoints, high data rates 1.2Mbps with 31 channels are also supported.

Firmware Upgrade Procedure

The Cisco Resilient Mesh bridge firmware can be installed by CLI or from IoT FND.

For more information on upgrading the firmware, see the latest Release Notes for Cisco 1000 Series Connected Grid Routers for Cisco IOS Release at:

FND Configuration

Cisco Resilient Mesh solution is managed and monitored by the Cisco IoT Field Network Director (FND), which provides the necessary backend network configuration, monitoring, event notification services, network stack firmware upgrade, as well as FND outage and meter registration. IoT FND also retrieves statistics on network traffic from the interface.



IR510 and IR530 will be supported only with FND Release 4.1 or greater. Refer to the Cisco IoT Field Network Director User Guides for details.

CoAP Simple Management Protocol

Cisco Resilient Mesh implements the CoAP Simple Management Protocol (CSMP) for remote configuration, monitoring, and event generation over the IPv6 network. The CSMP service is exposed over both the mesh and serial interfaces.

Power-outage Notification

Cisco Resilient Mesh supports timely and efficient reporting of power outages and restorations.

In the event of a power outage, Cisco Resilient Mesh enters power-outage notification mode and the node stops listening for traffic to conserve energy. Cisco Resilient Mesh triggers functions to conserve energy by notifying the communication module and neighboring nodes of the outage. The outage notification is sent using the same security settings as any other UDP/IPv6 datagram transmission.

In the event of a power restoration, a Cisco Resilient Mesh node sends a restoration notification using the same communication method as the outage notification. The communication modules unaffected by the power outage event deliver the restoration notification.

Registration of Endpoint

You can register and manage Cisco Resilient Mesh Endpoints (RMEs) such as meters using the IoT FND (which uses the CSMP protocol).

Limitations and Restrictions

Cisco recommends that you review this section before you begin working with the module. These are known limitations that will not be fixed, and there is not always a workaround for these issues. Some features might not work as documented, and some features might be affected by recent changes to the router hardware or software.

  • CSCub49104

    Symptom: Output from show mesh-security session all does not show all current mesh security sessions.

    Conditions: This issue occurs in the output of the show mesh-security session all command.

    Workaround: To find out the mesh-key status of a meter, use the show mesh-security session mac <mac-address> command.

  • CSCvs69721

    Symptom: IR530 will hang if downgrading from 6.2 to 6.0.19 with unsupported phy modes configured.

    Conditions: This issue occurs when IR530 configured with phy mode 1 or 2 is downgraded from 6.2 to 6.0.19 (phy modes 1 and 2 are supported in 6.2 but not supported in 6.0.19).

    Workaround: The workaround is (1) creating a configuration file with supported phy modes in 6.0, or (2) changing phy mode to a supported phy mode in 6.0 before downgrade.

  • CSCvu31508

    Symptom: WiSUN: Demo mode not mapping to network scale after upgrade from 5.6.x to 6.3.

    Conditions: In 5.6.x, demo = True, after upgrade to 6.3.x the network scale is large.

    Workaround: The workaround is to configure the network scale manually and reboot after the upgrade.

  • CSCvv02636

    Symptom: Itron30 EST: reenroll 802.1x certificate failed after manufacture idevid cert is expired on 6.3

    Conditions: When itron30's 802.1x certificate in 5.6.x is close to lifetime, at this time, upgrade itron30 from 5.6.x to 6.3 or afterwards. After upgrade to 6.3 or afterwards, the 802.1x certificate is copied as Manufacture IDevid for EST use, and when this copied Manufacture IDevid is expired, itron30 node on 6.3 can not do bootstrap EST process.

    Workaround: Before upgrade from 5.6.x to 6.3, do reenrollment of 802.1x public key and provide a long lifetime to this cert, so that when itron30 boots up on 6.3, the copied Manufacture IDevID cert can also get a long lifetime. This could provide a long-term way for itron30 node to do EST in the future.

  • CSCvn79551

    Symptom: No EAP response after sending the first EAP fragment to IR529 or CGEREFx.

    Conditions: 1) Set the EAP fragment size to 1024 bytes on radius server. 2) Cert file of the server is larger than 1024 bytes. 3) Trigger mesh node to do authentication. After radius server sent the first EAP fragment to mesh node, mesh node didn't reply any information, thus the authentication failed to continue.

    Workaround: Modify the max EAP fragment size to 512 bytes on radius server.

  • CSCvn79799

    Symptom: Node can't get online after downgraded from 6.x to 6.0.19 when mesh mixed with 6.0 and 6.x.

    Conditions: The WPAN image is not downgraded.

    Workaround: Downgrade the WPAN image and all other nodes to 6.0.19 as well.

  • CSCvs56568

    Symptom: 6.2 bridge can not work with Wi-SUN 6.1 if enable PON RPL.

    Conditions: This issue occurs when WPAN image is 6.2, and RPL PON instance is set on CGR.

    Workaround: Disable RPL PON instance on CGR, or upgrade all ir5xx to 6.2 image.

  • CSCvs57388

    Symptom: Wi-SUN: Node cannot register to fnd when node and wpan version mismatch.

    Conditions: This issue occurs when node is in release 6.1 and CGR WPAN is in release 6.2. Same problem exists when node is in release 6.2 and WPAN is in release 6.1.

    Workaround: Use the same release image on node and CGR WPAN. When upgrade from 6.1 to 6.2 using FND, upgrade the node first and then upgrade WPAN.

  • CSCvs57488

    Symptom: After image upgrade to 6.2.16 or later, IR510 EUI may be changed. Node may get a new global ipv6 address. The old EUI/address in CGR RPL table and FND will not work anymore.

    Conditions: This issue occurs when upgrade image from 6.x (for example, 6.0.x or 6.1.x) to 6.2.16 or later. Some IR510 EUI may be changed, but not all of them have this issue.

    Workaround: Import the new EUI to the FND and remove the old EUI. Wait for the old address timeout on the CGR RPL table.


This section addresses the Open and Resolved caveats that are relevant to Cisco Resilient Mesh. This section also provides information on how to use the Bug Tool Kit to find further details on the caveats.

Open Caveats

This section summarizes open caveats to the Cisco Resilient Mesh.

  • CSCvy33223

    Symptom: Short time upstream traffic interrupt intermittently observed with high load.

    Conditions: In WiSUN mode, run long duration traffic on IR510.

    Workaround: There is no workaround.

Accessing Bug Search Tool

You can use the Bug Search Tool to find information about caveats for this release, including a description of the problems and available workarounds. The Bug Search Tool lists both open and resolved caveats.

To access Bug Search Tool, you need the following items:

  • Internet connection

  • Web browser

  • user ID and password

To access the Bug Search Tool, enter the following URL:

Feature History


Cisco IOS Release

Feature information

Cisco Resilient Mesh firmware 6.4

Cisco IOS Release 15.9(3)M4 or later

Cisco Resilient Mesh enhancement.

Related Documentation

Consult the following resources for related information about the Connected Grid WPAN Module for technical assistance.

Hardware Overview and Installation