Bug ID 2208817: Web Acceleration RAM Cache cache expiration not refreshed on 304 responses due to ID1620785 fix side-effect in v17.1.3+

Last Modified: Feb 03, 2026

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

Known Affected Versions:
17.1.3, 17.1.3.1

Opened: Jan 21, 2026

Severity: 3-Major

Symptoms

After cache expiration, BIG-IP receives HTTP 304 (Not Modified) from backend with matching ETag but fails to refresh cache TTL, causing repeated backend revalidation requests instead of serving from cache.

Impact

This causes performance degradation - BIG-IP fails to offload backend servers as expected.

Conditions

-- HTTP Web Acceleration (RAM Cache) is enabled on the virtual server. -- The cached HTTP response includes an ETag header. -- The cached object expires based on its cache-control directives (for example, Cache-Control: max-age). -- BIG-IP is running a software version v17.1.3 or later.

Workaround

None

Fix Information

None

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips