Bug ID 609575: BIG-IP drops ACKs containing no max-forwards header

Last Modified: Aug 19, 2026

Affected Product(s):
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, 11.6.3.1, 11.6.3.2, 11.6.3.3, 11.6.3.4, 11.6.4, 11.6.5, 11.6.5.1, 11.6.5.2, 11.6.5.3, 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

Fixed In:
13.0.0, 12.1.2

Opened: Aug 08, 2016

Severity: 3-Major

Symptoms

When a sip profile is in use and receives an acknowledgment packet missing the Max-Forwards header, BIG-IP will treat the packet as un-forwardable and does not forward the ACK. This can be experienced as a specific cilent being unable to make a call.

Impact

BIG-IP treats packets with the missing header as having a value of 0, which means "Do not forward".

Conditions

This would only be seen when BIG-IP is connected to specific clients that fail to populate the Max-Forwards header on an ACK.

Workaround

None

Fix Information

None

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips