Bug ID 1756525: ixlv driver could have failed hardware offload with TSO off

Last Modified: Jul 08, 2025

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

Known Affected Versions:
17.1.1.3, 17.1.1.4, 17.1.2, 17.1.2.1, 17.1.2.2, 17.5.0

Fixed In:
17.5.1

Opened: Nov 28, 2024

Severity: 2-Critical

Symptoms

IPv4 packets for TLS alerts contain empty IP checksums.

Impact

Empty checksums will cause TLS clients to reject TLS alert messages.

Conditions

-- The ixlv driver is used by tmm -- TSO is disabled

Workaround

Change driver type to use xnet in tmm_init.tcl by inputting `device driver pci vendor_dev 8086:1889 xnet` or for a specific PCI device with `device driver pci XX:XX.X xnet`

Fix Information

Removed offloading IPv4 header checksum to the hardware unless TSO is on and so use what BIG-IP calculates instead.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips