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Forum Discussion

emile's avatar
emile
Icon for Nimbostratus rankNimbostratus
Oct 25, 2023

POST requests lost between two vs intermittently

Hi, Since we upgraded our BIG-IP F5 from 14.1.4.6 to 17.1.0.2, we encountered a loss of POST requests between virtualserver and our backend. This is always the same request which is blocked. Firs...
application delivery
Enes_Afsin_Al's avatar
Enes_Afsin_Al
Icon for MVP rankMVP
Oct 25, 2023

Hi emile,

Packet capture can help you troubleshoot the issue.

Starting from v16.1.0, a new feature available in the HTTP profile. Allow space title name feature, which is disabled by default, may be triggering this issue.

Allow Space Header Name: Specifies whether to allow white space in an HTTP header between the header name and the separator colon in an HTTP request or response. When Enabled, the BIG-IP system ignores white space between the header name and the colon. This feature is disabled by default.
https://my.f5.com/manage/s/article/K40243113

 

emile's avatar
emile
Icon for Nimbostratus rankNimbostratus
Oct 26, 2023

Hi Enes,

Thanks a lot for your answer. 
I've tried to pass the value of tmm.http.rfc.allowwsheadername to disable in v14.1.4.6 and I didn't manage to reproduce the issue. 

To be sure, I'll enable the setting concerned in v17 and see if the problem disappears.

 

  • emile's avatar
    emile
    Icon for Nimbostratus rankNimbostratus
    Oct 26, 2023

    Unfortunately, the problem persists with the Allow Space Header Name enabled.

    • emile's avatar
      emile
      Icon for Nimbostratus rankNimbostratus
      Nov 16, 2023

      We can confirm that the bug was introduced in v16, we upgraded to v15 and the bug disappeared. We looked for similar issues that appeared in v16 but didn't find anything conclusive. any help would be most welcome.