In-Order Delivery; About Reordering Network Frames - Cisco AP775A - Nexus Converged Network Switch 5010 Configuration Manual

In-Order Delivery

Step 5
Step 6
In-Order Delivery
In-order delivery (IOD) of data frames guarantees frame delivery to a destination in the same order that they
were sent by the originator.
Some Fibre Channel protocols or applications cannot handle out-of-order frame delivery. In these cases,
switches in the Cisco Nexus 5000 Series preserve frame ordering in the frame flow. The source ID (SID),
destination ID (DID), and optionally the originator exchange ID (OX ID) identify the flow of the frame.
On a switch with IOD enabled, all frames received by a specific ingress port and destined to a certain egress
port are always delivered in the same order in which they were received.
Use IOD only if your environment cannot support out-of-order frame delivery.
If you enable the in-order delivery feature, the graceful shutdown feature is not implemented.

About Reordering Network Frames

When you experience a route change in the network, the new selected path may be faster or less congested
than the old route.
Figure 72: Route Change Delivery
In the figure above, the new path from Switch 1 to Switch 4 is faster. In this scenario, Frame 3 and Frame 4
may be delivered before Frame 1 and Frame 2.
If the in-order guarantee feature is enabled, the frames within the network are delivered as follows:
Cisco Nexus 5000 Series Switch CLI Software Configuration Guide
586
Command or Action
switch(config)#fcroute fcid interface
fc slot/port domain domain-id metric
value remote vsan vsan-id
switch(config)#fcroute fcid netmask
interface fc slot/port domain domain-id
vsan vsan-id
Configuring Fibre Channel Routing Services and Protocols
Purpose
Adds a static route to the RIB. If this is an active route
and the FIBFIB = Forwarding Information Base records
are free, it is also added to the FIB.
If the cost (metric) of the route is not specified, the default
is 10.
Configures the netmask for the specified route the in
interface (or SAN port channel). You can specify one of
three routes: 0xff0000 matches only the domain, 0xffff00
matches the domain and the area, 0xffffff matches the
domain, area, and port.
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