Brocade Fabric OS Administrator's Guide Supporting Fabric OS v6.3.0 (53-1001336-02, November 2009)

Fabric OS Administrator’s Guide 63
53-1001336-02
Routing policies
4
AP route policy
On the Brocade 7500 switch and FR4-18i blade, there are eight internal physical links used by EX_
and VEX_Port functionality. The links are shared by both ingress and egress traffic on EX_ and
VEX_Ports. The AP (appliance) route policy dedicates some links for ingress traffic and some links
for egress traffic.
The AP Dedicated Link Policy relieves internal congestion in an environment where:
• There is a large amount of traffic going through both directions at the same time.
• There is a reduction of the effect of slow devices on the overall switch performance.
It is recommended that the default AP Shared Link Policy be used for most environments. Also, it is
recommended that you design a SAN that will localize Host to Target traffic by reducing the amount
of traffic through the router. The two additional AP policies supported under exchange-based
routing are:
• AP Shared Link policy (default)
• AP Dedicated Link policy
The AP policies are independent of the routing policies. Every routing policy supports both AP
policies.
ATTENTION
Setting this policy is a disruptive process.
Routing in Virtual Fabrics
Virtual Fabrics support DPS on all partitions. DPS is limited where multiple paths are available for a
logical fabric frame entering a Virtual Fabric chassis from a base fabric that is sent out using one of
the dedicated ISLs in a logical switch.
The AP policy affecting the DPS behavior, whether it is exchange-based, device-based, or
port-based, is configured on a per logical switch basis. IOD and DLS settings are set per logical
switch as well. IOD and DLS settings for the base switch affect all traffic going over the base fabric
including any logical fabric traffic that uses the base fabric.
CAUTION
Setting the routing policy is disruptive to the fabric because it requires that you disable the switch
where the routing policy is being changed.
Setting the routing policy
1. Connect to the switch and log in as admin.
2. Enter the switchDisable command to disable the switch.
3. Take the appropriate following action based on the route policy you choose to implement:
• If Exchange-based policy is required, enter the aptPolicy 3 command.
• If Port-based policy is required, enter the aptPolicy 1 command.