Reference Guide

552 | Layer 2
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Figure 29-3. Configuring Redundant Layer 2 Pairs without Spanning Tree
You configure a redundant pair by assigning a backup interface to a primary interface with the switchport
backup interface
command. Initially, the primary interface is active and transmits traffic and the backup
interface remains down. If the primary fails for any reason, the backup transitions to an active UP state. If
the primary interface fails and later comes back up, it remains as the backup interface for the redundant
pair.
Dell Networking OS supports only Gigabit, 10-Gigabit, and 40-Gigabit ports and port channels as primary/
backup interfaces in redundant pairs. (A port channel is also referred to as a Link Aggregation Group
(LAG). See Chapter 21, Interfaces, Port Channel Interfaces on page 411 for more information.) If the
interface is a member link of a LAG, the following primary/backup interfaces are also supported:
• primary interface is a physical interface, the backup interface can be a physical interface
• primary interface is a physical interface, the backup interface can be a static or dynamic LAG
• primary interface is a static or dynamic LAG, the backup interface can be a physical interface
• primary interface is a static or dynamic LAG, the backup interface can be a static or dynamic LAG
In a redundant pair, any combination of physical and port-channel interfaces is supported as the two
interfaces in a redundant pair. For example, you can configure a static (without LACP) or dynamic (with
LACP) port-channel interface as either the primary or backup link in a redundant pair with a physical
interface.
To ensure that existing network applications see no difference when a primary interface in a redundant pair
transitions to the backup interface, be sure to apply identical configurations of other traffic parameters to
each interface.
If you remove an interface in a redundant link (remove the module of a physical interface or delete a port
channel with the
no interface port-channel command), the redundant pair configuration is also removed.