Bug ID 503652: Some SIP UDP connections are lost immediately after enabling a blade on the Active HA unit.

Last Modified: Oct 17, 2023

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

Known Affected Versions:
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 HF1, 11.5.3 HF1, 11.6.0, 11.6.1, 11.6.2, 11.6.3,,,,, 11.6.4, 11.6.5,,,, 12.1.0 HF1, 12.1.0 HF2, 12.1.1 HF1, 12.1.1 HF2, 12.1.2 HF1, 12.1.2 HF2

Fixed In:
12.0.0, 11.6.0 HF6, 11.5.3 HF2

Opened: Jan 29, 2015

Severity: 2-Critical

Related Article: K17162


When a blade is enabled on a cluster while it is actively processing SIP UDP traffic, some packets might be lost.


Some SIP UDP traffic packets might be lost.


This occurs in an Active HA cluster containing VIPRION B2100 blades with the udp.hash value set to 'ipport' and client-side round robin TMM disaggregation enabled.


Do not enable a blade in a cluster while the blade is processing SIP UDP traffic.

Fix Information

Some SIP UDP connections are now retained after enabling a blade on the Active HA unit.

Behavior Change

As part of this fix, there are two new DB variables: -- arp.gratuitousrate -- arp.gratuitousburst The functionality of these DB variables is documented in K11985: Overview of the arp.gratuitousrate and arp.gratuitousburst database variables :: https://support.f5.com/csp/article/K11985.

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips