erps ring (Layer 2 Ethernet interface view)

Function

The erps ring command adds a port to an ERPS ring and specifies a role for the port.

The undo erps ring command removes a port from an ERPS ring and the port role configuration.

By default, ports are not added to ERPS rings, and no port roles are specified.

Format

erps ring ring-id [ rpl { neighbour | owner } ]

undo erps ring ring-id

Parameters

Parameter	Description	Value
ring-id	Specifies the ID of an ERPS ring.	The value is an integer ranging from 1 to 255.
rpl	Specifies the port type to be added to an ERPS ring.	-
neighbour	Specifies the port to be added to an ERPS ring as the RPL neighbor port.	-
owner	Specifies the port to be added to an ERPS ring as the RPL owner port.	-

Views

Layer 2 100GE interface view, Layer 2 10GE interface view, 25GE-L2 view, 400GE-L2 view, Layer 2 40GE interface view, Layer 2 50GE interface view, Eth-Trunk interface view, Layer 2 GE interface view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
erps	write

Usage Guidelines

Usage Scenario

After an ERPS ring is created, run the erps ring command in the interface view to add Layer 2 ports to the ERPS ring to allow transmission of R-APS PDUs. Each device that is added to an ERPS ring is a node, and each node cannot have more than two ports being added to the ERPS ring.

ERPS defines three port roles: RPL owner port, RPL neighbor port (only in ERPSv2), and ordinary port. The link where the RPL owner port resides is the RPL.

RPL owner port
An RPL owner port is a ring port responsible for blocking traffic over the RPL to prevent loops. An ERPS ring has only one RPL owner port.
When the node on which the RPL owner port resides receives an R-APS PDU indicating that a link or node on the ring fails, it unblocks the RPL owner port to allow the port to send and receive traffic. This mechanism ensures that traffic is not interrupted.
RPL neighbor port
An RPL neighbor port is a ring port directly connected to an RPL owner port and helps reduce the number of times FDB entries are refreshed.
RPL owner and neighbor ports are both blocked under normal conditions to prevent loops.
If an ERPS ring fails, both RPL owner and neighbor ports are unblocked.
Ordinary port
Ordinary ports are ring ports other than the RPL owner and neighbor ports.
An ordinary port monitors the status of the directly-connected ERPS link and sends R-APS PDUs to inform the other ports if the link status changes.

Prerequisites

The erps ring command has been run to create the specific ERPS ring.

Before adding a port to an ERPS ring, ensure that:

Spanning Tree Protocol (STP) is not enabled on the port. If the port has STP enabled, run the stp disable command to disable STP.
The port is not a Layer 3 port. If the port is a Layer 3 port, run the portswitch command to switch the port to the Layer 2 mode.
The control VLAN and ERP instance have been configured using the control-vlan and protected-instance commands in the ERPS ring view.
ERPSv2 has been specified for the ERPS ring using the version v2 command if the port will be specified as an RPL neighbor port.

Configuration Impact

If any port has been added to the ERPS ring, the control VLAN cannot be changed. If the configured control VLAN needs to be deleted, run the undo erps ring command in the interface view or the undo port command in the ERPS ring view, and run the undo control-vlan command to delete the control VLAN.

If any port has been added to the ERPS ring, no ERP instance can be modified. If the configured ERP instance needs to be deleted, run the undo erps ring command in the interface view or the undo port command in the ERPS ring view, and run the undo protected-instance command to delete the ERP instance.

Precautions

Before removing a port from an ERPS ring or changing the port role, run the shutdown command to shut down the port. Then remove the port or change the port role and run the undo shutdown command to enable the port. If the port is left disabled, traffic will be interrupted.

If ports added to an ERPS ring are all ordinary ports, any port on the device with the largest MAC address will be blocked.

A port cannot be added to an ERPS ring in any of the following conditions:

The port is enabled with a spanning tree protocol.
The port is added to an Eth-Trunk interface.
The port is added to a Monitor Link group.

Example

# Add GE 0/1/1 to ERPS ring 2.

<HUAWEI> system-view
[~HUAWEI] erps ring 2
[*HUAWEI-erps-ring2] control-vlan 100
[*HUAWEI-erps-ring2] protected-instance all
[*HUAWEI-erps-ring2] quit
[*HUAWEI] interface GigabitEthernet 0/1/1
[*HUAWEI-GigabitEthernet0/1/1] portswitch
[*HUAWEI-GigabitEthernet0/1/1] stp disable
[*HUAWEI-GigabitEthernet0/1/1] erps ring 2