Dell Unity™ Family Unisphere® Command Line Interface User Guide

Manage Fail-safe networking (physical deployments only)

Learn about Fail-safe networking (FSN) and which attributes are used to manage FSN in the CLI.

A Fail-Safe Network (FSN) is a high-availability feature that extends link failover into the network by providing switch-level redundancy. An FSN appears as a single link with a single MAC address and potentially multiple IP addresses. An FSN can be a port, a link aggregation, or any combination of the two. An FSN adds an extra layer of availability to link aggregations alone. Link aggregations provide availability in the event of a port failure. FSNs provide availability in the event of a switch failure. Each port or link aggregation is considered as a single connection. Only one connection in an FSN is active at a time. All the connections making up the FSN share a single hardware (MAC) address.

If the system detects a failure of the active connection, it will automatically switch to the standby connection in the FSN. That new connection assumes the network identity of the failed connection, until the primary connection is available again. You can designate which connection is the primary port/connection. To ensure connectivity in the event of a hardware failure, create FSN devices on multiple I/O modules or onboard ports. The FSN components are connected to different switches. If the network switch for the active connection fails, the FSN fails over to a connection using a different switch, thus extending link failover out into the network.

When replicating from one Unity system to another, configure the FSN the same way on both systems as a best practice. You will need to manually configure the FSN on the destination before setting up replication. Otherwise, if you set up the FSN on the destination after replication is configured, you will need to use the override option to select the FSN as the interface for the destination NAS server.