How to Prevent Network Loops with ERPS on Omada Industrial Switches

Contents

Introduction

Requirements

Configuration

Deployment Topology

ERPS Configuration Parameters

Configuration Procedure

Conclusion

Introduction

ERPSv2 (Ethernet Ring Protection Switching) is a Layer 2 ring protection protocol that prevents network loops and provides fast recovery in Ethernet ring networks. By blocking a designated Ring Protection Link (RPL) during normal operation and automatically restoring traffic paths when a link failure occurs, ERPSv2 helps maintain network redundancy and service continuity. This guide shows how to configure ERPSv2 on Omada Industrial Series Switches, including major ring and sub-ring deployment, to create loop-free and highly available industrial Ethernet networks.

Requirements

• Omada Industrial Switch firmware compatible with Omada Controller v6.3 and above

Configuration

In an ERPS network, each switch that participates in the ring is called a node. The group of interconnected switches using the same Control VLAN forms an ERPS ring. The Control VLAN is used only to transmit ERPS protocol packets and should not be used for normal user traffic. User traffic VLANs are protected by a Protection Instance, which defines which VLANs are controlled by ERPS during normal forwarding and protection switching. This design allows the ERPS protocol to decide when traffic should be forwarded or blocked, helping avoid loops and service disruption.

Deployment Topology

Each ERPS ring uses different port roles to control traffic forwarding. The RPL Owner port is the main port responsible for blocking the RPL under normal conditions, and each ERPS ring has only one RPL Owner. The RPL Neighbor port is directly connected to the RPL Owner port and is supported in ERPSv2.

Other ports in the ring are Normal ports, which monitor directly connected ERPS links and report topology changes. Ports in an ERPS ring can be in either Forwarding state, where they forward user traffic and ERPS packets, or Discarding state, where they only send and receive ERPS packets.

The following topology illustrates a typical ERPSv2 deployment of one Major Ring (maj1) and one Sub-Ring (sub2). Switches A, B, C, and D form the major ring, while switches C, D, and E form the sub-ring. The two rings are interconnected through switches C and D, which act as the interconnection nodes between the major ring and the sub-ring.

Two Ring Protection Links (RPLs) are defined in this topology:

• RPL1 is established between switches A and B, with switch A configured as the RPL Owner (1O) and switch B as the RPL Neighbor (1N).
• RPL2 is established between switches E and D, with switch E configured as the RPL Owner (2O) and switch D as the RPL Neighbor (2N).

All remaining ring ports are configured as Normal ports and participate in ERPS protection switching.

Note:

• ERPS configuration on Omada Industrial Series Switches is currently supported only in Standalone Mode.
• Feature availability and configuration options may vary by switch model. Please refer to the Web UI for the actual parameters supported by your device.
• Omada Industrial Series Switches currently support ERPSv2 only. ERPSv2 is fully compatible with ERPSv1 and can interoperate with third-party ERPSv1 devices. However, to achieve optimal convergence performance and avoid unexpected compatibility issues, it is recommended to deploy Omada Industrial Series Switches throughout the ERPS network whenever possible.
• When a Sub-Ring is configured in Virtual Channel (VC) Mode, manually add the relevant 1. interconnection ports on the major ring as tagged members of the Sub-Ring Control VLAN so that topology notifications can be transmitted correctly.
• The Control VLAN used by an ERPS ring must be a VLAN ID that has not been created under 802.1Q VLAN. ERPS configuration can be applied only when an unused VLAN ID is selected as the Control VLAN.
• It is recommended to dedicate the Control VLAN exclusively to ERPS operation. Avoid adding non-ERPS ports to the Control VLAN whenever possible.

ERPS Configuration Parameters

Throughout this article, the topology shown above is used as the deployment example. The following sections explain how to configure the key ERPS parameters required for ring protection, including the Ring ID, Control VLAN, Protection Instance, Ring Type (Major Ring or Sub-Ring), Member Ports, Port Roles (RPL Owner, RPL Neighbor, and Normal), ERPS Version, and protection timers. These parameters define the ERPS ring topology and determine how the network detects failures and performs protection switching.

The table below summarizes the ERPS settings used in this deployment example. Before configuring ERPS, connect each switch to the management network and ensure that the switch can be accessed through the Web UI. You may either obtain an IP address automatically through DHCP or assign a static IP address according to your network requirements. In this example, static IP addresses are used only for management and testing purposes to avoid address conflicts during the configuration process.

The following parameters are identical on all switches unless otherwise specified:

Protection Instance: 1

WTR Timer: 5

Guard Timer: 200

Hold-off Timer: 0

Revertive Mode: Enable

Configuration Procedure

Step 1 (Optional). Access the Switch Web Interface

Connect each switch to the management network and access its Web management interface in Standalone Mode. The switch can be accessed using either a DHCP-assigned IP address or a manually configured management IP address. Ensure that you can successfully log in to the Web UI before proceeding with the ERPS configuration.

Step 2. Enable 802.1Q VLAN

Navigate to VLAN > 802.1Q VLAN and enable the 802.1Q VLAN function on all switches

Step 3. Disable STP and Verify Loop Detection Status

Navigate to Spanning Tree > STP Config on each switch. Disable STP before configuring ERPS to avoid conflicts with the ring protection mechanism.

Step 4. Create the Major Ring ERPS Instance

Navigate to ERPS > ERPS Config. The ERPS page displays the configured rings and their current operating status.

Under the Add New ERPS section, create a new ERPS ring. Using the major ring on Switch A as an example, configure the following parameters: Ring ID as 1, Control VLAN as 10, Ring Type as Major Ring, Member Port 1 as RPL Owner, Member Port 2 as Normal, Protection Instance as 1, WTR Timer as 5, Guard Timer as 200, Hold-off Timer as 0, MEL as 6, and Revertive Mode as Enable. After completing the configuration, click Apply to save the settings and create the ERPS ring.

Step 5. Configure a Sub-Ring (Switch C Example)

After the main ring has been configured, proceed with the sub-ring configuration on Switch C. Configure the parameters as follows: Ring ID = 2, Control VLAN = 20, Member Port 1 = Normal, and Virtual Channel = Enable or Disable according to the deployment requirements. The Notify Ring ID must match the Ring ID of the major ring so that topology change notifications can be propagated correctly between the two rings.

As Switch C is an interconnection node between the major ring and the sub-ring, only one member port needs to be configured for the sub-ring instance. This port is used to connect the sub-ring and participate in ERPS protection switching.

Step 6. Verify the Protection Instance Configuration

The created Protection Instance will be displayed in the Protection Instance table as shown below, allowing you to verify that the VLAN-to-instance mapping has been configured successfully.

Step 7. Configure the Remaining Switches

Repeat the preceding configuration steps on the remaining switches according to the Configuration Parameters table. After completing the configuration on all switches, connect the switches based on the topology shown. Once all links are established, proceed to verify the ERPS ring status.

Step 8. Verify ERPS Ring Status

Once all links are established, navigate to ERPS and verify the ring status on each switch. When the configuration is successful and the ERPS ring has converged, the State of the corresponding ERPS instance will change to Idle, indicating that the ring is operating normally and the ERPS protection mechanism is active.

Step 9. Perform Protection Switching Operations (Optional)

After the ERPS ring is operating normally and the State is displayed as Idle, users can perform protection switching operations from the top of the ERPS page. The supported operations include Force Switch (FS), Manual Switch (MS), and Clear. These functions are mainly used for maintenance, troubleshooting, failover testing, or manually changing the forwarding path.

• Force Switch (FS): Immediately blocks the selected port regardless of the current ring status.
• Manual Switch (MS): Manually changes the blocking point when the ring is in the Idle or Pending state.
• Clear: Clears an existing FS or MS operation and restores normal ERPS behavior.

Conclusion

This article demonstrates how to configure a typical ERPSv2 major ring and sub-ring topology on Omada Industrial Series Switches, including Protection Instance creation, ERPS ring configuration, port role assignment, and status verification.

After the configuration is completed and all switches are connected according to the topology, the ERPS instance should enter the Idle state under normal operation, while the Protection state indicates that ERPS has detected a link failure and has performed protection switching to maintain service availability.

To learn more about each function and configuration, please visit Support Home to download or check the manual for your product.