Service Manual

(as shown in the following illustration). The redundant pairs feature allows you to create redundant links in networks that do not use
STP by conguring backup interfaces for the interfaces on either side of the primary link.
NOTE: For more information about STP, refer to Spanning Tree Protocol (STP).
Assign a backup interface to an interface using the switchport backup command. The backup interface remains in a Down
state until the primary fails, at which point it transitions to Up state. If the primary interface fails, and later comes up, it becomes the
backup interface for the redundant pair. Dell Networking OS supports Gigabit, 10 Gigabit, and 40-Gigabit interfaces as backup
interfaces.
Apply all other congurations to each interface in the redundant pair such that their congurations are identical, so that transition to
the backup interface in the event of a failure is transparent to rest of the network.
Figure 62. Conguring Redundant Layer 2 Pairs without Spanning Tree
You congure 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 trac 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). For more information, refer to Interfaces) 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
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Layer 2