Mar 27, 2026 - For details about updated CVE-2025-53521 (BIG-IP APM vulnerability), refer to K000156741.

Forum Discussion

grmanikantan's avatar
grmanikantan
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Aug 10, 2023

Need help on irule: External content for internal request in F5

I have a requirement and trying to achive through irule but some how not working as expected.. Requirement: Client to access Internal URL : https://www.abcd.com F5 to call the content from this e...
security
grmanikantan's avatar
grmanikantan
Icon for Altostratus rankAltostratus
Aug 10, 2023

Hi AubreyKing,

Thanks for your response.

While updating this irule, i got below messages...

01070151:3: Rule [/Common/irule-test] error: /Common/irule-test:4: error: [undefined procedure: internal_call_and_respond][internal_call_and_respond]
/Common/irule-test:7: error: [command is not valid in the current scope][proc internal_call_and_respond {} {
set backend_response [HTTP::get "https://www.myexternal.com"]
set response_status [HTTP::status]
set response_headers [HTTP::header]
}]

 

Paulius's avatar
Paulius
Icon for MVP rankMVP
Aug 10, 2023

grmanikantan Based on the log it seems like the subroutine isn't configured properly. Before we go any further with this, what's the requirement that is forcing you to have to take care of this on the F5?

  • grmanikantan's avatar
    grmanikantan
    Icon for Altostratus rankAltostratus
    Aug 11, 2023

    Hi Paul, My requirement is simple. There is one internal URL which is configured in F5 VS, if user hit that URL ( https://www.abcd.com ) F5 should be respond with external content (webpages) which is available in the outside of F5 (https://www.myexternal.com). I'm trying various methods subroutine is one of that...

    • Paulius's avatar
      Paulius
      Icon for MVP rankMVP
      Aug 11, 2023

      grmanikantan If you are just forwarding the content of that external site you might be better off configuring a pool with a pool member using the FQDN www.myexternal.com and then using a string map to replace instances of www.abcd.com with www.myexternal.com before it's set to the the destination. Keep in mind that you will have to enable SNAT for this to work most likely. The stringmap should look something like the following.

      when HTTP_REQUEST priority 500 {

    if {[HTTP::uri] starts_with "/public/"} {
        HTTP::host [string map {"www.abcd.com" "www.myexternal.com"}[HTTP::host]]
        pool POOL_ExternalWeb_443
    }

}