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

The State Of HTTP/2 Full Proxy With F5 LTM

Code is community submitted, community supported, and recognized as ‘Use At Your Own Risk’. In this article, I will attempt to summarize the known challenges of an HTTP/2 full proxy setup, point ou...
Updated Mar 10, 2026
Version 9.0
application delivery
Juergen_Mang's avatar
Juergen_Mang
Icon for MVP rankMVP
Dec 09, 2025

Hi Sven,

I discovered this Bug already in the combination with the ASM::unblock in iRules.

The known issues list is terrifying long...

svs's avatar
svs
Icon for Cirrostratus rankCirrostratus
Dec 09, 2025

Ah...sorry. I've overseen this reference. But at least I found it outside of iRules. 😄

However, I hardly ever see F5 LTM setups with HTTP/2 full proxy configured.

Maybe because of the terrifying long list of known issues or bad experience 😉. I've never had good results with HTTP/2, neither measurable nor felt. Either because of buggy HTTP/2 configuration in the backend or because of the perceived lack of support on the BIG-IP or known issues...

  • Juergen_Mang's avatar
    Juergen_Mang
    Icon for MVP rankMVP
    Dec 09, 2025

    Ah...sorry. I've overseen this reference. But at least I found it outside of iRules.

    This makes it even worse.

    I hope this article will encourage F5 to prioritize addressing the issues with HTTP/2. In any case, I would prefer to see the known issues list worked through rather than new features being introduced.