Bug ID 707691: BIG-IP handles some pathmtu messages incorrectly

Last Modified: Oct 16, 2023

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

Known Affected Versions:
11.5.5, 11.5.6, 11.5.7, 11.5.8, 11.5.9, 11.5.10, 11.6.0, 11.6.1, 11.6.2, 11.6.3, 11.6.3.1, 11.6.3.2, 11.6.3.3, 11.6.3.4, 11.6.4, 11.6.5, 11.6.5.1, 11.6.5.2, 11.6.5.3, 12.0.0, 12.0.0 HF1, 12.1.0 HF1, 12.0.0 HF2, 12.1.0 HF2, 12.0.0 HF3, 12.0.0 HF4, 12.1.1 HF1, 12.1.1 HF2, 12.1.2 HF1, 12.1.2 HF2, 12.1.0, 12.1.1, 12.1.2, 12.1.3, 12.1.3.1, 12.1.3.2, 12.1.3.3, 12.1.3.4, 12.1.3.5, 12.1.3.6, 12.1.3.7, 12.1.4, 12.1.4.1, 12.1.5, 12.1.5.1, 12.1.5.2, 12.1.5.3, 12.1.6, 13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1, 13.1.0, 13.1.0.1, 13.1.0.2, 13.1.0.3, 13.1.0.4, 13.1.0.5, 13.1.0.6, 13.1.0.7, 13.1.0.8, 13.1.1, 13.1.1.2, 13.1.1.3, 14.0.0, 14.0.0.1, 14.0.0.2, 14.0.0.3, 14.0.0.4

Fixed In:
14.1.0, 14.0.0.5, 13.1.1.4

Opened: Feb 23, 2018

Severity: 3-Major

Symptoms

FastL4 virtual servers incorrectly handle some pathmtu messages, such as ICMPv4 unreachable/fragmentation needed and ICMPv6 packet too big.

Impact

pmtu message is erroneously ignored.

Conditions

This occurs when the following conditions are true: -- The client sends a window scaling factor greater than 0 (zero). -- The server sends a window scaling factor equal to 0 (zero). -- The pmtu message is within the window, but does not reflect the exact expected sequence number. The delta is bigger than the advertised window scaled at a factor of 0 (zero).

Workaround

There is no workaround at this time.

Fix Information

This issue no longer occurs.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips