Bug ID 478257: Unnecessary re-transmission of packets on ICMP notifications even when MTU is not changed

Last Modified: Apr 10, 2019

Bug Tracker

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

Known Affected Versions:
10.2.0, 10.2.4, 11.2.1, 11.3.0, 11.4.0, 11.4.1, 11.5.0, 11.5.1, 11.5.1 HF1, 11.5.1 HF10, 11.5.1 HF11, 11.5.1 HF2, 11.5.1 HF3, 11.5.1 HF4, 11.5.1 HF5, 11.5.1 HF6, 11.5.1 HF7, 11.5.1 HF8, 11.5.1 HF9, 11.5.2, 11.5.2 HF1, 11.5.3, 11.5.3 HF1, 11.6.0, 11.6.0 HF1, 11.6.0 HF2, 11.6.0 HF3, 11.6.0 HF4, 11.6.0 HF5

Fixed In:
12.0.0, 11.6.0 HF6, 11.5.4 HF3, 11.5.3 HF2, 11.4.1 HF9, 11.2.1 HF15, 10.2.4 HF12

Opened: Sep 06, 2014
Severity: 3-Major
Related AskF5 Article:
K16449

Symptoms

Re-transmission of fragment needed packets.

Impact

Burst traffic generated.

Conditions

Multiple ICMP Destination Unreachable with Fragmentation needed code messages.

Workaround

Disable Path MTU Discovery by doing the following, "tmsh modify sys db tm.enforcepathmtu value disable"

Fix Information

BIG-IP no longer re-transmits packets if the MTU is not changed.

Behavior Change