Release Notes for Cisco Resilient Mesh Release 6.1

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

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.


For a detailed description of the Cisco Resilient Mesh software in Release 6.1, 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 6.1




First Cisco IOS/CG-OS Release that Supports the Feature

IR510, IR530

EST support

Supports end to end solution integration with IR510 using Enrollment over Secure Transport (EST).


All platforms

CG-Mesh supports certificate chain of length up to 4 layers.

Supports to handle certificate that includes root, manufacturer, sub manufacturer, and end-entity chains.


IR510, IR530

BSdiff/BSpatch for firmware download

End to end solution for the image diff support for firmware download.


All platforms

FND to verify config push is done and also the config change status real time.

FND can show real time configuration push status to the nodes.


All platforms

Address EOS of Win2008 Radius Server

End to end solution for the new version of Windows Radius server Win2016.


WPAN, IR510, IR530

IR510 and IR530 work with FSK

All the new devices like cgm-wpan-ofdm-fcc, IR510, and IR530 can work with FSK devices in the field.


All platforms

Blacklist of node takes effect immediately

Blacklist of device takes effect immediately rather than waiting for mesh key to expire and new authentication mechanism to be used.


All platforms

TLS 1.2 integration

Supports TLS 1.2.


IR509, IR529, IR510, IR530, WPAN(OFDM)

Wi-SUN 1.0 compliance for CG-Mesh Device

Wi-SUN compliance image for CG-Mesh devices.


System Requirements

If you plan to run Cisco Resilient Mesh Release 6.1, you must have the following required hardware and software components:


Minimum Cisco IOS/CG-OS Software Release Required

Cisco 1000 Series Connected Grid Router

Cisco IOS Release 15.8(3)M2

Cisco IR530


Cisco IR529


Cisco IR510


Cisco IR509






IoT Field Network Director

Release 4.5



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 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 CG-OS 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.


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.

  • CSCvg11696

    Symptom: IR510: IPv6 Ethernet address is shown as lowpan address.

    Workaround: When configuring FND global IPv6 address, the address-match-length of FND and node's lowpan address should be greater than that of FND and node's Ethernet address.

  • CSCvn79551

    Symptom: No EAP response after sending the first eap fragment to 529/CGEREFx.

    Conditions: Set the EAP fragment size to 1024 bytes on radius server, and the cert file of the server is larger than 1024 bytes.

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

  • CSCvn79799

    Symptom: Node can't get online after downgrade from 6.1 to 6.0.19 when mesh mixed with 6.0 and 6.1.

    Conditions: The WPAN image is not downgraded.

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

  • CSCvo81976

    Symptom: AM/AR prefers higher rate in high_rssi_high_loss scenario induced by noise leading to continous loss.

    Conditions: RSSI between sending and receiving devices are good. Receiving device is impacted by noise leading to high packet loss rate.

    Workaround: There is no workaround.

  • CSCvp88638

    Symptom: IR510: GPS status retrieve periodically failed after reload.

    Conditions: Enable GPS and reload device IR510.

    Workaround: Disable GPS and enable it again.

  • CSCvo80623

    Symptom: When IR509 is upgraded from Release 5.6 to Release 6.1, the configuration of MAPTStatus, ETHconfig, and NAT44StaticMap will be lost.

    Conditions: This occurs when IR509 is upgraded from Release 5.6 to Release 6.1.

    Workaround: Reconfigure MAPTStatus, ETHconfig, and NAT44StaticMap.

Resolved Caveats

This section summarizes resolved caveats to the Cisco Resilient Mesh.

  • CSCvk44604

    Node detaches to its parents in adaptive mode when average resend times larger than four.

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/CG-OS Release

Feature information

Cisco Resilient Mesh firmware 6.1

Cisco IOS Release 15.8(3)M2

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