Vyatta Network OS Documentation

Learn how to install, configure and operate the Vyatta NOS, which helps drive our virtual networking & physical platforms portfolio.

Match rules

We use match rules to separate the stream of traffic into multiple flows, in the second stage of classification.

We give each flow a class number that ranges from 1 to 255. We name each match rule, and each one can have multiple match criteria which we join together with the and operator.

Each class can have multiple named match rules. The names of the match rules determine the order in which QoS will check them. QoS checks match rules in the alpha-numerical order of their names.

Note: For the sake of efficiency, name the most popular match rules in such a way that QoS will check them first.

Each match rule can have multiple match criteria. For a packet to match a match rule, it must satisfy all of the criteria in that match rule.

If the packet matches a match rule, QoS will assign it to the match rule's class, and check no more match rules. If the packet doesn't match a match rule, then QoS checks the next match rule.

Finally, if the packet does not match any match rules then QoS will assign the packet to the default class 0 and process it with the default profile.

You can also associate actions with match rules. Then, when a packet matches the rule, the system can apply a series of actions to the packet.