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Aziz-90s's avatar
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Dec 05, 2022

irule block uri for external users when url has special characters such as $

Hi all I've tried an irule on VIP for the website example to block the uri for external users only example /_api/$metadata I need to block this path /_api/$metadata  so what I tried is  When HTTP_...
  • AlexBCT's avatar
    Dec 05, 2022

    Hi Aziz, 

    Two things that I noticed in the iRule; 

    1. there is no space between equals"example"} - although I suspect this is just an edit error for the question here, I thought I'd mention it, just in case... 😉 

    2. "/_api/$metadata" - are you referring an iRule variable or is this part of the actual URI? If it is a variable, where is it exactly declared? If part of the URI, the iRule will probably think it's a variable and interpret as such. To avoid this behaviour, try putting a backslash in front of it to clearly tell the iRule to take is as its literal value. ( "/_api/\$metadata" ) 

    If the above two things didn't help, did you see any messages in the ltm log? (/var/log/ltm) and what is the behaviour when connecting from inside a private net or outside? Lastly, any chance of any proxies in between that are always hiding behind an outside address? 

    Regarding Local Traffic Policies; yes, they are brilliant and often a great replacement for basic iRules (...but iRules are still awesome!). I think your example might indeed be a good one for an LTP. Have a look here: but also just give it a go in the F5 GUI and you'll be able to figure it out quickly. (go to Local Traffic - Policies - Create new policy)

    Hope one of these tips helps. 


  • Aziz-90s's avatar
    Dec 05, 2022

    Hi Alex

    Thanks for replying 

     The /_api/$metadata is part of uri,

    also I forgot to mention that I did a little research about special characters in uri

    and it turns out that we could somehow avoid or resolve this issue by using a syntax Set_encode something like that 

    have u hear any thing like this.

    I'll try ur suggestions & reply back

    much appreciated