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

Forum Discussion

Injazat-SOC's avatar
Injazat-SOC
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Jan 23, 2020

F5 Proxy protocol irule support

One of our service is hosted in Cloudflare which is redirecting the request to our F5 LTM where the actual service is hosted. By default when the request coming from cloudflare it is not sending the...
application delivery
big-ip
irules
Injazat-SOC's avatar
Injazat-SOC
Icon for Nimbostratus rankNimbostratus
Jan 27, 2020

Unfortunately we dont have the true client IP option for our application. The option we have now is to use proxy protocol v1 or v2.

When we apply the proxy protocol receiver irule the published service is not working, however when we allow no proxy in the irule it works. It seems LTM is not receiving the proxy protocol as applied in the irule hence it is resting the connection. Even when the service works with no-proxy option we are not getting real client IP details. If we can get answers for the below it may help us to narrow down the issue.

 

  1. Why the LTM is not able to intercept proxy protocol, is there any issues with irule?
  2. How to confirm that LTM is receiving the proxy protocol header (Cloudflare confirmed that they are sending proxy protocol v1)
  3. How to get the real client IP using proxy protocol