Bug ID 826349: VXLAN tunnel might fail due to misbehaving NIC checksum offload

Last Modified: Nov 07, 2022

Bug Tracker

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

Known Affected Versions:
13.1.0, 13.1.0.1, 13.1.0.2, 13.1.0.3, 13.1.0.4, 13.1.0.5, 13.1.0.6, 13.1.0.7, 13.1.0.8, 13.1.1, 13.1.1.2, 13.1.1.3, 13.1.1.4, 13.1.1.5, 13.1.3, 13.1.3.1, 13.1.3.2, 13.1.3.3, 13.1.3.4, 13.1.3.5, 13.1.3.6, 13.1.4, 13.1.4.1, 13.1.5, 13.1.5.1, 14.1.0, 14.1.0.1, 14.1.0.2, 14.1.0.3, 14.1.0.5, 14.1.0.6, 14.1.2, 14.1.2.1, 14.1.2.2, 14.1.2.3, 14.1.2.4, 14.1.2.5, 14.1.2.6, 14.1.2.7, 14.1.2.8, 14.1.3, 14.1.3.1, 14.1.4, 14.1.4.1, 14.1.4.2, 14.1.4.3, 14.1.4.4, 14.1.4.5

Fixed In:
15.1.0, 14.1.4.6

Opened: Sep 13, 2019
Severity: 3-Major

Symptoms

Some NICs, e.g., on BIG-IP 2000/4000 platforms, perform checksum offloading for UDP, and erroneously mark a 0 (zero) checksum as a checksum failure, even though the UDP header includes an optional, 16-bit one's complement checksum that provides an integrity check. If the computed checksum is 0, it is transmitted as all ones. In this case the NIC should accept the checksum, but it does not.

Impact

VXLAN tunnel fails.

Conditions

NIC offload checksum of 0.

Workaround

None.

Fix Information

The VXLAN tunnel now ignores invalid checksums if the checksum is 0.

Behavior Change