Bug ID 646495: BIG-IP may send oversized TCP segments on traffic it originates

Last Modified: Jun 20, 2019

Bug Tracker

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

Known Affected Versions:
12.1.0, 12.1.0 HF1, 12.1.0 HF2, 12.1.1, 12.1.1 HF1, 12.1.1 HF2, 12.1.2, 12.1.2 HF1, 12.1.2 HF2, 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, 13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1

Fixed In:
13.1.0

Opened: Feb 18, 2017
Severity: 4-Minor

Symptoms

Traffic from the Linux host on BIG-IP may send TCP segments larger than the advertised TCP MSS of a remote host.

Impact

TMM may send traffic to a TCP host that exceeds the host's advertised MTU.

Conditions

Received TCP MSS (plus protocol overhead) smaller than configured MTU of interface. Linux host sending large TCP segments, such as SNMP getbulk replies.

Workaround

disable segmentation offload for the vnic

Fix Information

BIG-IP no longer originates traffic to TCP hosts that exceed that host's advertised MTU.

Behavior Change