Avaya P334T-ML manual Port Redundancy Operation

Chapter 11 Avaya P330 Layer 2 Features

Port Redundancy

Port redundancy involves the duplication of devices, services, or connections, so that, in the event of a failure, the redundant device, service, or connection can take over for the one that failed.

In addition to Link Aggregation Groups—which comprise the basic redundancy mechanism within the switch—the P330 offers an additional port redundancy scheme. To achieve port redundancy, you can define a redundancy relationship between any two ports in a stack. One port is defined as the primary port and the other as the secondary port. If the primary port fails, the secondary port takes over. You can configure up to 20 pairs of ports (or LAGs) per stack for port redundancy, and 1 pair per stack for intermodule redundancy. Each pair contains a primary and secondary port. You can configure any type of port to be redundant to any other.

Port Redundancy Operation

The Port Redundancy feature supports up to 20 pairs of ports per stack. The redundant or secondary port takes over when the primary port link is down. Port redundancy provides for the following in the P330:

•Switchback from the secondary to primary port is allowed

•Switching time intervals can be set by the user

Port Redundancy interworks with the Spanning Tree Algorithm.

The Port Redundancy feature functions as follows:

•Port Redundancy enables the user to establish 20 pairs of ports. Within each pair, primary and secondary ports are defined. To prevent loops, only one port is enabled at a time.

•Following initialization, the primary port is enabled and the secondary port is disabled.

—If the active port link fails, the system enables the secondary port.

—If the secondary port is enabled and the primary port link becomes available again, the system will “switchback” to the primary port, unless configured otherwise by the user.

•Two timers are available:

—“min-time-between-switchovers” —minimum time (in seconds) between the failure of the primary port link and switchover to the secondary (backup) port.

The first time the primary port fails, the switchover is immediate. This timer applies to subsequent failures.

—“switchback-interval” — the minimum time (in seconds) that the primary port link has to be up (following failure) before the system switches back to the primary port. The “none” parameter, if configured, prevents switching back to the primary.

100 Avaya P334T-ML User’s Guide