Bug ID 760695: FastL4 might drop invalid PMTU (ICMP) message

Last Modified: Oct 06, 2020

Bug Tracker

Affected Product:  See more info
BIG-IP LTM(all modules)

Known Affected Versions:
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, 13.1.1.4, 13.1.1.5, 13.1.3, 13.1.3.1, 13.1.3.2, 13.1.3.3, 13.1.3.4, 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

Fixed In:
16.0.0

Opened: Mar 07, 2019
Severity: 4-Minor

Symptoms

In an n-path deployment, FastL4 might drop invalid PMTU (ICMP) messages.

Impact

FastL4 might drop invalid PMTU (ICMP) message. As BIG-IP does not see the full handshake, this is expected.

Conditions

N-path (Direct Server Return) is configured.

Workaround

None

Fix Information

The db key TM.FastL4_invalid_pmtu_passthrough was added to allow for this situation.

Behavior Change