Contents

Configuring Reth interfaces· 1

About Reth interfaces· 1

Applicable scenario· 1

Operating mechanism·· 1

Configuration restrictions and guidelines· 2

Configuring a Reth interface· 2

Displaying and maintaining Reth interfaces· 2

Reth interface configuration example· 3

Network requirements· 3

Configuration procedure· 3

Verifying the configuration· 3

Configuring Reth interfaces

About Reth interfaces

A redundant Ethernet (Reth) interface is a virtual Layer 3 interface that uses two member interfaces to ensure link availability. One member interface is active and the other is inactive. When the active interface fails, the inactive interface becomes active. The member interface switchover does not interrupt traffic.

Applicable scenario

As shown in Figure 1, M-GigabitEthernet 1/0/0/0 and M-GigabitEthernet 1/0/0/1 are member interfaces of a Reth interface. The Reth interface selects the member interface to forward traffic as follows:

·     When both member interfaces are operating correctly, the Reth interface forwards traffic through M-GigabitEthernet 1/0/0/0 and places M-GigabitEthernet 1/0/0/1 in inactive state.

·     When M-GigabitEthernet 1/0/0/0 fails, M-GigabitEthernet 1/0/0/1 becomes active and the Reth interface switches traffic over to M-GigabitEthernet 1/0/0/1.

Figure 1 Reth interfaces

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Operating mechanism

A member interface of a Reth interface can be in either of the following states:

·     Active—The interface can forward packets. A Reth interface can have only one active member interface.

·     Inactive—The interface cannot forward packets.

A Reth interface determines the state of its member interfaces by using the following rules:

·     When both member interfaces are physically up, the member interface with the higher priority is active and the member interface with lower priority is inactive. The priorities of the member interfaces are user configurable.

·     When the active member interface goes down physically, the inactive interface automatically becomes active to forward packets.

·     When both member interfaces are physically down, both interfaces are inactive.

The Reth interface uses the device bridge MAC address as its MAC address and can be configured with an IP address. For the upstream and downstream devices, they are connected to the Reth interface. The switchover between the Reth member interfaces is not visible to the network and does not cause network topology changes.

Configuration restrictions and guidelines

To use the Reth interface features, make sure the MPUs have a minimum of two management Ethernet ports.

The IP addresses of the management Ethernet ports become invalid after you assign them to a Reth interface. To log in to the device, you must use the IP address assigned to the Reth interface.

Configuring a Reth interface

When you configure a Reth interface, follow these restrictions and guidelines:

·     You can assign a maximum of two member interfaces to a Reth interface. The member interfaces must have different priorities.

·     Before you delete a Reth interface, make sure all its member interfaces have been removed.

To configure a Reth interface:

Displaying and maintaining Reth interfaces

Execute display commands in any view and reset commands in user view.

Reth interface configuration example

Network requirements

As shown in Figure 2, configure a Reth interface as follows:

·     Assign M-GigabitEthernet 1/0/0/0 and M-GigabitEthernet 1/0/0/1 to the Reth interface.

·     Assign a higher priority to M-GigabitEthernet 1/0/0/0 for it to be the active member interface.

Figure 2 Network diagram

Configuration procedure

# Create Reth 1, and assign an IP address to the interface.

[Sysname] interface reth 1

[Sysname-Reth-1] ip address 1.0.0.3 24

# Assign M-GigabitEthernet 1/0/0/0 and M-GigabitEthernet 1/0/0/1 to Reth 1, and set their priority to 100 and 80, respectively.

[Sysname-Reth1] member interface M-GigabitEthernet1/0/0/0 priority 100

[Sysname-Reth1] member interface M-GigabitEthernet1/0/0/1 priority 80

Verifying the configuration

# Verify that M-GigabitEthernet 1/0/0/0 is active and M-GigabitEthernet 1/0/0/1 is inactive.

[Sysname-Reth1] display reth interface reth 1

Reth1 :

  Redundancy group  : N/A

  Member                    Physical status       Forwarding status    Presence status

  MGE1/0/0/0                UP                    Active               Normal

  MGE1/0/0/1                UP                    Inactive             Normal

# Shut down M-GigabitEthernet 1/0/0/0.

[Sysname-Reth1] quit

[Sysname] interface M-GigabitEthernet 1/0/0/0

[Sysname-M-GigabitEthernet 1/0/0/0] shutdown

# Verify that M-GigabitEthernet 1/0/0/1 becomes active and M-GigabitEthernet 1/0/0/0 becomes inactive.

[Sysname-M-GigabitEthernet 1/0/0/0] display reth interface reth 1

Reth1 :

  Redundancy group  : N/A

  Member                   Physical status         Forwarding status    Presence status

  MGE1/0/0/0               DOWN                   Inactive             Normal

  MGE1/0/0/1               UP                     Active               Normal