irules

We’ve expanded over the years to include systems, configuration, advanced modules, security, etc, but programmability has historically been the bread and butter of what we do. Given the success we had with February’s security month, this...

We’ve covered quite a bit of ground in the Getting Started with iRules and Intermediate iRules series. In this series, we’ll dive even deeper down the rabbit hole, starting with the table command. This article is a primer for the power of tables,...

Scan is used to parse out strings. It takes a string and based on your format parameters, stores the matches in one or more variables. It also returns the number of conversions performed, so it can be used in a conditional as well. For all the...

The binary scan command, like the scan command covered in this Advanced iRules series, parses strings. Only, as the adjective indicates, it parses binary strings. In this article, I’ll highlight the command syntax and a few of the format string...

A regular expression or regex for short is essentially a string that is used to describe or match a set of strings, according to certain syntax rules. Regular expressions ("REs") come in two basic flavors: extended REs ("ERE"s)...

Sometimes an iRule will load and run without producing any errors, but does not achieve the desired results. In this article, I will outline the basic process of examining your iRule logic against live traffic by walking through a simple example:...

To say we’re getting to the heart of the matter, dealing with string commands and parsing, re-arranging and modification, would almost be saying it too lightly…understating. String manipulation is a massive part of iRules, and is in fact a solid...

For this article in the Intermediate iRules series we’ll begin arming you with some knowledge on data-groups. As such, this article will endeavor to answer the following: What is a data-group? What is a class? What are the benefits of a...

In this article, we're going to cover loop control structures and how to gain efficiency therein. One of the things that makes iRules so powerful is the fact that it is effectively a full scripting language at your fingertips with which you...

We've talked about variables in the Getting Started with iRules series, but we're going to cover specifically the list object type of variable. Most of the TCL commands for use in manipulating lists are available in iRules: list - Create...