Brocade Access Gateway Administrator's Guide v6.2.0 (53-1001189-01, April 2009)

Access Gateway Administrator’s Guide 19
53-1001189-01
Port Grouping policy
2
Figure 7 shows that if you create port groups and when an N_Port goes offline, the F_Ports being
routed through that port will fail over to any of the N_Ports that are part of that port group and are
currently active. For example, if N_Port4 goes offline then F_Ports7 and 8 are routed through to
N_Port 3 as long as N_Port 3 is online because both N_Ports3 and 4 belong to the same port
group, PG2. If no active N_Ports are available, the F_Ports are disabled. The F_Ports belonging to a
port group do not failover to N_Ports belonging to another port group.
FIGURE 7 Port grouping behavior
When a dual redundant fabric configuration is used, F_Ports connected to a switch in AG mode can
access the same target devices from both of the fabrics. In this case, you must group the N_Ports
connected to the redundant fabric into a single port group. It is recommended to have paths fail
over to the redundant fabric when the primary fabric goes down.
FIGURE 8 Port Group 1 (pg1) setup
ATTENTION
If N_Ports are connected to unrelated fabrics are grouped together, N_Port failover within a port
group can cause the F_Ports to connect to a different fabric and the F_Ports may lose connectivity
to the targets they were connected to before the failover, thus causing I/O disruption as shown in
Figure 8.
F_Port1
F_Port2
F_Port3
N_Port2
N_Port1
N_Port4
N_Port3
F_Port4
PG1
PG2
F_Port5
AG
Fabric-1
Fabric-2
Storage
Array-1
Storage
Array-2
F_Port6
F_Port7
F_Port8
Storage
Array-1
Storage
Array-2
F_Port1
N_Port1
F_Port2
F_Port3
N_Port2
F_Port4
PG1
AG
Fabric-1
Fabric-2