Describe the routing policy rules in a Linux environment and ‘a rather long and complex, with this article I just want to make an introduction to what you can do with your linux box and the commands available in the package iproute2.
For more info i suggest the site: http://www.policyrouting.org/
iproute2 is a collection of utilities for controlling TCP and UDP IP networking and traffic control in Linux, in both IPv4 and IPv6 networks. It is currently maintained by Stephen Hemminger. The original author, Alexey Kuznetsov, was responsible for the QoS implementation in the Linux kernel.