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

Forum Discussion

sstorholm's avatar
sstorholm
Icon for Nimbostratus rankNimbostratus
Mar 11, 2022

URL Rewrite in LTM Policy

I have an issue that after an update to a web application the IIS rewrite rules no longer work, so I thought I'd migrate the whole thing over the our F5s that are already doing TLS for the site.  Wh...
application delivery
CA_Valli's avatar
CA_Valli
Icon for MVP rankMVP
Mar 13, 2022

Hello, this is the most basic I can come up with assuming that finnish language append is optional.

  • I've wrote this on mobile, there might be typos, lmk

 

when HTTP_REQUEST {

set lan ""

if {[HTTP::uri] ends_with "?language=en"}{

set lan "?language=en"

} elseif {[HTTP::host] eq "swedishapp.domain.com" }{set lan "?language=sve"}

 HTTP::header replace "Host" "192.0.2.10"

HTTP::uri "/appname/$lan" 

}

CA_Valli's avatar
CA_Valli
Icon for MVP rankMVP
Mar 13, 2022

Reading request again I noticed you mentioned you have an ltm policy for host rewrite, eventually remove the http header instruction as it might clash with ltm policy statements

(try not to have conflicts on instructions as is might result in unexpected behavior)

 

also if finnish language is required you can change the default $lan value from "" to "?language=fin" at variable set instruction time,