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teemo_13's avatar
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Dec 22, 2022

Which takes precedence? iRule or Cookie-based Persistence?

Hi DevCentral, I am wondering what would take precedence in this type of scenario.

A VS with a cookie persistence applied with an iRule to redirect traffic based on the URL on the request.

If a fresh connection is established, will it use the cookie first before applying the iRule?

If an already established connection has a cookie already, will it redirect the traffic based on the cookie or will it look at the URL of the request before processing?

5 Replies

  • We never though on this. I beleive redirection will be first then cookie

  • Hi teemo_13 

    I think in this case that f5 IRule will take precedence first as the incoming traffic hits first in the IRules configured on the box.

    • teemo_13's avatar
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      Is this true for both fresh connection and a persistent connection?

      For example a client is connected with a persistent connection and the same client had a  request with the URL identifier set on the iRule. Will the iRule still take precedence?

  • Hi teemo_13 , 
    Let we explain , we have an iRule used to block specific resource on website , let we say "" , we will configure an iRule to block any one write "" url in his browser and permit anything else to this website. 
    Thats good till now , I will assume that I have configured a Cookie Persistence profile so each user will be served by the first server " Pool_mem " replied first time. 

    so that , If someone wants to access any resource on "" website other than "" should work without issues , but if someone tries to access this resource "" , it should be blocked by irule Even if this a valid user and is already served by specific Pool_member due to Cookie persistence. 

    > in my Example , I want to describe that this user should be blocked by iRule whatever its a new connection or an existing persistence connection. 

    > hence , we can deduce that iRule should look at the request first of all and take the precedence. 
    I want to say also that iRule is the first Component the Virtual server use againt requests in case there is an iRule attached already through this Virtual server.