Bug ID 610710: Pass IP TOS bits from incoming connection to outgoing connection

Last Modified: Mar 17, 2021

Bug Tracker

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

Known Affected Versions:
11.6.0, 11.6.0 HF1, 11.6.0 HF2, 11.6.0 HF3, 11.6.0 HF4, 11.6.0 HF5, 11.6.0 HF6, 11.6.0 HF7, 11.6.0 HF8, 11.6.1, 11.6.1 HF1, 11.6.1 HF2, 11.6.2, 11.6.2 HF1, 11.6.3,,,,, 11.6.4, 11.6.5,,,, 12.0.0, 12.0.0 HF1, 12.0.0 HF2, 12.0.0 HF3, 12.0.0 HF4, 12.1.0, 12.1.0 HF1, 12.1.0 HF2, 12.1.1, 12.1.1 HF1, 12.1.1 HF2, 12.1.2, 12.1.2 HF1, 12.1.2 HF2, 13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1

Fixed In:
13.1.0, 12.1.3

Opened: Aug 12, 2016
Severity: 3-Major


ToS is set to 0 when going through a SIP profile.


Currently outgoing packets TOS bits are configured via profile and are not affected by TOS bits of incoming packet.


This occurs when a SIP profile is in use and ToS is set.



Fix Information

Outgoing packets TOS bits can be configured via profile to preserve the TOS bits of incoming packet.

Behavior Change

This change will only change existing behavior if the transport protocol (TCP, UDP or SCTP) has the ip-tos-to-client attribute set to pass-through. If configured as pass-through, the TOS bits of the incoming packet containing a message will be used on the outgoing packets containing the message. Without this change, the TOS bits of the outgoing packet would be undefined if configured this way.