HP Brocade 4Gb SAN Switch for HP BladeSystem p-Class - Manual (Page 100)

100 Routing traffic
• 2: Device-based path selection on the on the SAN Switch 4/32 only
• 3: Exchange-based path selection, which is the default on the SAN Switch 4/32 only
The default policy usually provides the best performance. You should change the policy only if there is a
performance problem that you cannot resolve in other ways.
You must disable the switch before changing the routing policy, and reenable it afterward.
In this example, the routing policy is changed from exchange-based to device-based:
Assigning a static route
Assign a static route only when the active routing policy is port-based. When device-based or
exchange-based routing is active you cannot assign static routes.
To assign a static route, use the
urouteconfig
command. To remove a static route, use the
urouteremove
command.
NOTE: For the SAN Switch 2/32, Core Switch 2/64, and SAN Director 2/128, when you issue the
urouteconfig
command, two similar warning messages may be displayed if a platform conflict
condition occurs. The first message appears when the static routing feature detects the condition. The
second message appears when the dynamic load sharing feature detects the condition as it tries to
rebalance the route.
A platform conflict occurs if a static route was configured with a destination port that is currently down.
The static route is ignored in this case, in favor of a normal dynamic route. When the configured
destination port comes back up, the system attempts to reestablish the static route, and the conflict can
occur then.
Specifying frame order delivery
In a stable fabric, frames are always delivered in order, even when the traffic between switches is shared
among multiple paths. However, when topology changes occur in the fabric (for example, if a link goes
down), traffic is rerouted around the failure, and some frames could be delivered out of order. Most
destination devices tolerate out-of-order delivery, but some do not.
By default, out of order frame-based delivery is allowed to improve speed. You should force in-order
frame delivery across topology changes only if the fabric contains destination devices that cannot tolerate
occasional out-of-order frame delivery.
switch:admin> aptpolicy
Current Policy: 3
3: Default Policy
1: Port Based Routing Policy
2: Device Based Routing Policy
3: Exchange Based Routing Policy
switch:admin> switchdisable
switch:admin> aptpolicy 2
Policy updated successfully.
switch:admin> switchenable
switch:admin> aptpolicy
Current Policy: 2