Bug ID 424042: Virtual Edition instances with TSO enabled may drop packets

Last Modified: Oct 06, 2020

Bug Tracker

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

Known Affected Versions:
11.3.0, 11.4.0

Fixed In:
11.5.0, 11.4.1

Opened: Jun 26, 2013
Severity: 2-Critical

Symptoms

VE instances with TCP Segmentation Offload (TSO) enabled may drop packets. These packet drops are not recorded in tmstat tables, and are instead counted by the VE dataplane driver's statistics interface (see 'tx_tso_errcnt' in /proc/unic)

Impact

Packets can be dropped by the VE dataplane driver. These drops are not recorded in tmstat tables.

Conditions

VE instance with TSO enabled on Xen, VMware, and KVM hypervisors

Workaround

Disable TSO "tmsh modify sys db tm.tcpsegmentationoffload value disable"

Fix Information

Correct TSO checksum calculation for VE guests

Behavior Change