Displaying Routing And Adjacency Information - Cisco Nexus 3000 Series Configuration Manual

Managing the Unicast RIB and FIB
S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m
Using per-packet load sharing can result in out-of-order packets. Packets for a given pair of
Note
source-destination hosts might take different paths and arrive at the destination out of order. Make sure
you understand the implications of out-of-order packets to your network and applications. Per-packet
load sharing is not appropriate for all networks. Per-flow load sharing ensures packets always arrive in
the order that they were sent.
Per-packet load sharing uses the round-robin method to determine which path each packet takes to the
destination. With per-packet load sharing enabled on interfaces, the router sends one packet for
destination1 over the first path, the second packet for (the same) destination1 over the second path, and
so on. Per-packet load sharing ensures balancing over multiple links.
Use per-packet load sharing to ensure that a path for a single source-destination pair does not get
overloaded. If most of the traffic passing through parallel links is for a single pair, per-destination load
sharing will overload a single link while other links will have very little traffic. Enabling per-packet load
sharing allows you to use alternate paths to the same busy destination.
Per-packet load sharing on an interface overrides the global load-sharing configuration.
Note
You configure per-packet load sharing on the input interface. This configuration determines the output
interface that Cisco NX-OS chooses for the packet.
For example, if you have ECMP paths on two output interfaces, Cisco NX-OS uses the following
load-sharing methods for input packets on Ethernet 1/1:
•
•
The configuration for the other interfaces have no effect on the load-sharing method used for Ethernet
1/1 in this example.
To configure per-packet load sharing, use the following command in interface configuration mode:
Command
ip load-sharing per-packet
Example:
switch(config-if)# ip load-sharing
per-packet

Displaying Routing and Adjacency Information

You can display the routing and adjacency information.
To display the routing and adjacency information, use the following commands in any mode:
Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
10-6
Per-packet load sharing if you configure per-packet load sharing on Ethernet 1/1.
Per-flow load sharing.
Chapter 10
Purpose
Configures per-packet load sharing on an interface.
Managing the Unicast RIB and FIB