Fabric OS Administrator's Guide v7.0.0 (53-1002148-02, June 2011)
76 Fabric OS Administrator’s Guide
53-1002148-02
Frame order delivery
4
Assigning a static route
1. Connect to the switch and log in as admin.
2. Enter the uRouteConfig command.
Example of configuring a route
The following example shows how to configure a static route for all traffic coming in from port 1 and
addressed to domain 2 to go through port 5:
switch:admin> urouteconfig 1 2 5
done.
Removing a static route
1. Connect to the switch and log in as admin.
2. Enter the uRouteRemove command.
Frame order delivery
The order of delivery of frames is maintained within a switch and determined by the routing policy
in effect. The frame delivery behaviors for each routing policy are:
• Port-based routing
All frames received on an incoming port destined for a destination domain are guaranteed to
exit the switch in the same order in which they were received.
• Exchange-based routing
All frames received on an incoming port for a given exchange are guaranteed to exit the switch
in the same order in which they were received. Because different paths are chosen for
different exchanges, this policy does not maintain the order of frames across exchanges.
If even one switch in the fabric delivers out-of-order exchanges, then exchanges are delivered to the
target out of order, regardless of the policy configured on other switches in the fabric.
NOTE
Some devices do not tolerate out-of-order exchanges; in such cases, use the port-based routing
policy.
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 minimize the number of frames dropped.
Enabling in-order delivery (IOD) guarantees that frames are either delivered in order or dropped.
You should only force in-order frame delivery across topology changes if the fabric contains
destination devices that cannot tolerate occasional out-of-order frame delivery.