Bug ID 466761: Heartbeat, UDP packet with only double CRLF, on existing SIP flow results in connection loss.

Last Modified: Jul 18, 2026

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

Known Affected Versions:
11.5.1, 11.5.1 hf1, 11.5.1 hf2, 11.5.1 hf3, 11.5.1 hf4, 11.5.1 hf5, 11.5.1 hf6, 11.5.1 hf7, 11.5.1 hf8, 11.5.1 hf9, 11.5.1 hf10, 11.5.1 hf11, 11.5.2, 11.5.2 hf1, 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

Fixed In:
12.0.0, 11.5.3

Opened: Jun 11, 2014

Severity: 3-Major

Symptoms

Heartbeat, UDP packet with only double CRLF, on existing SIP flow might result in connection loss.

Impact

Connection might be terminated.

Conditions

SIP heartbeat message, a UDP packet with double CRLF, sent by the client to the server.

Workaround

None.

Fix Information

The heartbeat SIP message, which is a UDP packet with CRLF, is ignored and connection is maintained.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips