Bug ID 940209: Chunked responses with congested client connection may result in server-side TCP connections hanging until timeout.

Last Modified: Sep 13, 2023

Affected Product(s):
BIG-IP LTM(all modules)

Known Affected Versions:
14.1.0,,,,,, 14.1.2,,,,,,,,, 14.1.3,, 15.0.0, 15.0.1,,,,, 15.1.0,,,,,, 15.1.1

Fixed In:
15.1.2, 14.1.4

Opened: Aug 26, 2020

Severity: 3-Major


When an HTTP/2 profile is configured on the client side, chunked responses are always sent unchunked. When a connection to a client is congested, the BIG-IP system may not properly close established server-side connections causing subsequent HTTP/2 requests to stall.


HTTP/2 requests intermittently stall due to the existing server-side TCP connection remaining open.


-- A virtual server with an HTTP/2 profile configured on the client side. -- A server responds with a chunked response.


Configure an HTTP profile on the client side with a value of 'unchunk' on the response-chunking option.

Fix Information

HTTP/2 requests no longer stall, as the server side TCP connection is properly closed.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips