16.2.2 Configuring Uplink Redundant

The figure below describes an example uplink redundancy configuration. This subsection describes how to configure uplink redundancy based on this example.

Figure 16-8: Example of setting up uplink redundancy

On the Switch, this configuration configures port 1/0/1 as the primary port and port 1/0/2 as the secondary port. It also specifies 60 seconds as the automatic switch-back wait time and enables the sending of flush control frames.

<Structure of this section>

(1) Configuring Uplink Redundant

(1) Configuring Uplink Redundant

Points to note: Configure port 1/0/1 as the primary port and port 1/0/2 as the secondary port. Specify 60 seconds as the automatic switch-back wait time. You need to disable Spanning Tree Protocols before you configure uplink redundancy. Configure the sending of flush control frames on the primary port.

Command examples

(config)# spanning-tree disable

Disables a Spanning Tree Protocol.
(config)# interface gigabitethernet 1/0/1

(config-if)# switchport backup interface gigabitethernet 1/0/2 preemption-delay 60

Enters configuration mode for port 1/0/1.

In the configuration mode of port 1/0/1 as the primary port, configure port 1/0/2 as the secondary port. Also, set the automatic switch-back wait time to 60 seconds.
(config-if)# switchport backup flush-request transmit

(config-if)# exit

Enables the sending of flush control frames.

Notes

Before you configure uplink redundancy, the network is in a loop configuration. Shut down the primary port or the secondary port to prevent loops, and then set up the configuration.
If you want to specify the ports in a link aggregation group as the primary port, use a port channel interface. You cannot use an Ethernet interface in a link aggregation group as the primary port.