Brocade Access Gateway Administrator's Guide - Supporting Fabric OS v5.2.1 (53-1000430-01)

1-6 Access Gateway Administrator’s Guide

Publication Number: 53-1000430-01

Failover policy

The Brocade Access Gateway N_Port failover policy allows hosts to automatically remap to an online

N_Port if the N_Port they are connected to goes offline. The failover policy evenly distributes the

F_Ports that are mapped to an offline N_Port among all the online N_Ports. The failover policy is a

parameter of each N_Port. By default, the failover policy is enabled for all N_Ports.

The following sequence describes how a failover event occurs:

1. An N_Port goes offline.

2. All F_Ports mapped to that N_Port are disabled.

3. If the N_Port failover policy is enabled, the disabled F_Ports are remapped to an online N_Port.

The F_Ports are evenly distributed among the remaining online N_Ports.

4. The F_Port is re-enabled on the new N_Port.

5. The host establishes a new connection with the fabric.

Example: Failover Policy

This example shows the failover behavior in a scenario where two fabric ports go offline, one after the

other.

• First the edge switch F_A1 port goes offline, as shown in Figure 1-5 example 1 (left), causing the

corresponding Access Gateway N_1 port to be disabled.

The ports mapped to N_1 fail over; F_1 fails over to N_2 and F_2 fails over to N_3.

• Next the F_A2 port goes offline, as shown in Figure 1-5 example 2 (right), causing the

corresponding Access Gateway N_2 port to be disabled.