Configure Layer 2 Mesh Transparency in Industrial Wireless Access Points

Introduction

This document describes the functions and configuration of layer 2 mesh transparency features. 

Layer 2 Mesh Transparency

Layer 2 Transparency is a feature available on the IW9165 and IW9167 Access Points with firmware version 17.12.1 and above.

This feature allows the option to either block or allow generic Layer 2 packets through the IW network. The Ether types on the packets traversing the IW network are detected automatically and reported. 

It enables the seamless transmission of non-IP Layer 2 protocols across the wireless mesh network, extending the reach and capabilities of various industrial applications. 

Ether type is a two-octet field in the Ethernet Frame that indicates what type of protocol is being encapsulated inside the payload.

Apart from reserved Ether types, users are allowed the option to allow specific Ether types, Layer 2 Ether types, and Ethernet-I packets. The packet filtering is done at the ingress/egress points of the MPLS Tunnels.

The egress point is always the Mesh End of the network, and the ingress points can be Mesh points in the Fixed Infrastructure setup or the Vehicle radios in the Fluidity setup.

Many industrial devices and systems rely on legacy protocols like Modbus, DNP3, or proprietary protocols that operate at Layer 2 of the OSI model.  Layer 2 mesh transparency allows these devices to communicate seamlessly over the wireless mesh network, even if they are not IP-based.   

CLI Configuration

Detecting and Adding Ether types

The Ether type for Profinet packets 0x8892 and the Ether type for QNet 0x8204 are allowed by default.

1. The list of detected Ether types can be displayed with the command below.

MP#show mpls ether-filter

Ether-type   Direction       Description

0x6002       INGRESS         ---

0x86DD       INGRESS         IPv6

0x8035       INGRESS         RARP

2. The detected Ether types or all available Ether types can be added with the commands below.

MP#config mpls ether-filter allow-list add 0x86DD

MP#write

MP#reload

MP#config mpls ether-filter allow-list add all

MP#write

MP#reload

3. The added ether type configuration can be checked from the running config.

MP#show run

4. Specific Ether types can be deleted from the allow-list as well.

MP#config mpls ether-filter allow-list delete 0x86DD

MP#write

MP#reload

5. The detected Ether types can also be cleared with the command below.

MP#config mpls ether-filter table clear

GUI Configuration

The same configuration can be from the GUI of the Access Point (in CURWB mode). Navigate to the Ethernet filter field under Advanced Settings on the side panel of the GUI. 

Allowing all Ether types by selecting the check box for it.

Allowing only certain Ether types

Uncheck the Allow all ethernet types option and add the required Ether type. Click Save and Apply to execute the changes.

Clear detected Ether types by clicking on the Clear detected option on the GUI

Reserved Ether types 

            Certain Ether types are reserved and cannot be added or deleted from the list.

Any attempt to use it results in an error as shown below:

Ethernet 1 protocol 

Ethernet 1 protocol can be blocked or allowed from the CLI or the GUI as well.

MP#config mpls ether-filter ethernet-I block

MP#write

MP#show run

MP#config mpls ether-filter ethernet-I forward

MP#write

MP#show run

From the GUI of the radio, the Allow Ethernet 1 protocols checkbox can be checked to allow and unchecked to block Ethernet 1 frames. Click Save and Apply for the change to be applied.