Bug ID 420485: TMM silently drop non-SYN packet without TCP RST

Last Modified: Nov 22, 2021

Bug Tracker

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

Known Affected Versions:
10.2.4, 11.3.0, 11.4.0, 11.4.1

Fixed In:
11.5.0, 11.4.1 HF9

Opened: May 03, 2013
Severity: 4-Minor
Related Article:
K15048

Symptoms

In 11.0.0 and 11.3.0, TMM silently drops the non-SYN packet without TCP RST if TCP 3WHS has not yet established. In 11.2.1, TMM sends the reset. In 10.2.3, TMM rejects non-SYN packet.

Impact

When this occurs, there is no RST for non-SYN packets.

Conditions

TMM rejects non-SYN packet if TCP 3WHS has not yet established.

Workaround

None.

Fix Information

TMM now correctly sends a RST packet when it receives a non-SYN TCP packet for which no connection has been established. In some versions, TMM would silently drop the packet.

Behavior Change