The algorithm of ECMP

What is the algorithm of ECMP on XOS. Is it platform independent?

1 reply

Userlevel 6
Hello Elmer

There is a detail description of this in the EXOS Command Reference guide 15_4 page 2336.

Here's a brief summary

The ECMP hash uses CRC based on SIP, DIP and (by default), the L4 port numbers. If you
want, you can choose to exclude L4 port numbers by configuring "L3" using this XOS CLI
configure forwarding sharing [L3 | L3_L4]

ECMP support L3
Uses only Layer 3 IP addresses to select ECMP routes and load-sharing ports.
L3_L4 (Default)
Uses Layer 3 IP addresses and Layer 4 TCP/UDP port numbers, if present, to select
ECMP routes and load-sharing ports

You can download the command reference guide at

Hope that helps