About Enabling In-Order Delivery; Enabling In-Order Delivery - Cisco Nexus 5000 Series Configuration Manual

Configuring Fibre Channel Routing Services and Protocols
When the in-order delivery feature is enabled and a port channel link change occurs, the frames crossing the
SAN port channel are delivered as follows:
• Frames using the old path are delivered before new frames are accepted.
• The new frames are delivered through the new path after the network latency drop period has elapsed
Frames that cannot be delivered in order through the old path within the network latency drop period are
dropped.
Related Topics
Configuring the Drop Latency Time, on page 195

About Enabling In-Order Delivery

You can enable IOD for a specific VSAN or for the entire switch. By default, IOD is disabled on Cisco SAN
switches.
We recommend that you enable this feature only when devices that cannot handle any out-of-order frames
are present in the switch. Load-balancing algorithms within the switch ensure that frames are delivered in
order during normal fabric operation. The load-balancing algorithms based on source FC ID, destination FC
ID, and exchange ID are enforced in the hardware without any performance degradation. However, if the
fabric encounters a failure and the in-order delivery feature is enabled, the recovery will be delayed because
of an intentional pausing of fabric forwarding to purge the fabric of resident frames that could potentially be
forwarded out-of-order.

Enabling In-Order Delivery

You can enable in-order delivery for the switch.
SUMMARY STEPS
1. configuration terminal
2. in-order-guarantee
3. no in-order-guarantee
DETAILED STEPS
Command or Action
Step 1 configuration terminal
Example:
switch# configuration terminal
switch(config)#
Step 2
in-order-guarantee
Example:
switch(config)# in-order-guarantee
OL-27583-01
and all old frames are flushed.
Cisco Nexus 5000 Series NX-OS SAN Switching Configuration Guide, Release 5.2(1)N1(1)
Purpose
Enters global configuration mode.
Enables in-order delivery in the switch.
In-Order Delivery
193