Fault Tolerance - Broadcom NetXtreme BCM57 Series User Manual

NetXtreme User Guide Broadcom Gigabit Ethernet Teaming Services
The same algorithm applies if a third and fourth backup operation is initiated from the backup server. The
teamed interface on the backup server transmits a unicast G-ARP to backup clients to inform them to update
their ARP cache. Each client then transmits backup data along a route to the target MAC address on the backup
server.

Fault Tolerance

If a network link fails during tape backup operations, all traffic between the backup server and client stops and
backup jobs fail. If, however, the network topology was configured for both Broadcom SLB and switch fault
tolerance, then this would allow tape backup operations to continue without interruption during the link failure.
All failover processes within the network are transparent to tape backup software applications. To understand
how backup data streams are directed during network failover process, consider the topology in Figure 8. Client-
Server Red is transmitting data to the backup server through Path 1, but a link failure occurs between the backup
server and the switch. Because the data can no longer be sent from Switch #1 to the Adapter A interface on the
backup server, the data is redirected from Switch #1 through Switch #2, to the Adapter B interface on the backup
server. This occurs without the knowledge of the backup application because all fault tolerant operations are
handled by the adapter team interface and trunk settings on the switches. From the client server perspective, it
still operates as if it is transmitting data through the original path.
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April 2017 • 2CS57XX-CDUM514-R Page 128