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

Last Modified: Sep 13, 2023

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

Known Affected Versions:
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

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

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips