iRule

What is irule?

An iRule  is feature on the big ip platform for the ability of big ip to manipulate server side and client side traffic all the way through application layer. iRule is script that can be made for the big ip platform to give ability to manage anytime ip traffic. iRule has potential to directly control the traffic as it passes through the platform by parsing the client or server headers or the payload of that data in making decision based on the content inside of it.

iRule example could be pool/node selection, or URL/port redirects.

For example :

User wants to go to www.F5network.com/F5 it can go to www. F5 network.com/F51234. Another common usable of irule is redirecting http to https. IRULE composed of two main items:

• Event declaration
• TCL codes

Event is to define the state the connection currently in. When the connection event matches, the irule will be triggered.

Once the irule is triggered,  the TCL code inside  the irule will be executed on that request.
For example in this irule:

I am going to explain part per part of this irule is supposed to mean:

“when HTTP_REQUEST” is the event declaration. It shows the condition of the connection that must be met. When it is met it will trigger this irule.

Above picture shows that once the iRULE is triggered it will run the tcl code.

So how to read this iRULE:

It is triggered the irule which will run tcl code with the condition of:

Then do this following:

We will redirect traffic into https.

Maybe you will have many questions about irule including what the uri is.

I am going to explain to you in the next blog