Bug ID 421611: SIP messages through the SIP-ALG may be hairpinned when the destination address is not inside the NAT

Last Modified: Sep 13, 2023

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

Known Affected Versions:
11.3.0, 11.4.0, 11.4.1, 11.5.0, 11.5.1, 11.5.2, 11.5.3, 11.5.4, 11.5.5, 11.5.6, 11.5.7, 11.5.8, 11.5.9, 11.5.10

Fixed In:
11.6.0

Opened: May 21, 2013

Severity: 2-Critical

Related Article: K15993

Symptoms

SIP messages are sent directly to the peer and not to the SIP-Proxy when both peers are inside the NAT.

Impact

Some SIP messages may not be seen by the SIP-Proxy and cause missed messages and accounting gaps.

Conditions

-- CGNAT and SIP-ALG are configured. -- Peer1 and Peer2 are in the NAT'd network (subscribers). -- SIP-Proxy is located outside the NAT network (internet).

Workaround

None

Fix Information

SIP messages through the SIP-ALG are no longer hairpinned when the destination address is not inside the NAT.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips