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

Forum Discussion

Tyson_James's avatar
Tyson_James
Icon for Cirrus rankCirrus
Apr 25, 2016

Host Rewrite or iRule?

Hello All, I am a total noob when it comes to out F5 BIG-IP LTM. I know enough to do some pretty basis stuff. I have been asked to do something that I have never had to do before. My company ha...
application delivery
big-ip
irules
LTM
rewrite profile
Hannes_Rapp's avatar
Hannes_Rapp
Icon for Nimbostratus rankNimbostratus
Apr 25, 2016
when HTTP_REQUEST {

  if { ([string tolower [HTTP::host]] eq "externalsitea.company.com") && ([HTTP::path] eq "/" ) }{
    HTTP::header replace Host "internalsitexyz"
    HTTP::path "/aba/blabla/12345"
  } else {
    return
  }

}

Client talks to 'externalsitea.company.com' and meanwhile, behind the scenes, F5 forwards such requests to your Pool Member as 'GET internalsitexyz/aba/blabla/12345'.

That solution only masquerades headers. If you need to modify response payload (i.e. some HTML links), you will need to use a stream profile https://devcentral.f5.com/questions/rewrite-body-of-web-site

Hannes_Rapp's avatar
Hannes_Rapp
Icon for Nimbostratus rankNimbostratus
Apr 25, 2016
What do you mean by external site? I'm trying to understand if the external site is a different application that talks to the Oracle service which is hosted via F5?