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, 14.1.0.1, 14.1.0.2, 14.1.0.3, 14.1.0.5, 14.1.0.6, 14.1.2, 14.1.2.1, 14.1.2.2, 14.1.2.3, 14.1.2.4, 14.1.2.5, 14.1.2.6, 14.1.2.7, 14.1.2.8, 14.1.3, 14.1.3.1, 15.0.0, 15.0.1, 15.0.1.1, 15.0.1.2, 15.0.1.3, 15.0.1.4, 15.1.0, 15.1.0.1, 15.1.0.2, 15.1.0.3, 15.1.0.4, 15.1.0.5, 15.1.1

Fixed In:
15.1.2, 14.1.4

Opened: Aug 26, 2020

Severity: 3-Major

Symptoms

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.

Impact

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

Conditions

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

Workaround

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