Bug ID 1758193: Trunk with LACP and virtual-wire flaps after an upgrade.

Last Modified: Jun 28, 2025

Affected Product(s):
BIG-IP Install/Upgrade, LTM(all modules)

Known Affected Versions:
16.1.0, 16.1.1, 16.1.2, 16.1.2.1, 16.1.2.2, 16.1.3, 16.1.3.1, 16.1.3.2, 16.1.3.3, 16.1.3.4, 16.1.3.5, 16.1.4, 16.1.4.1, 16.1.4.2, 16.1.4.3, 16.1.5, 16.1.5.1, 16.1.5.2, 16.1.6, 17.1.0, 17.1.0.1, 17.1.0.2, 17.1.0.3, 17.1.1, 17.1.1.1, 17.1.1.2, 17.1.1.3, 17.1.1.4, 17.1.2, 17.1.2.1, 17.1.2.2, 17.5.0, 17.5.1

Opened: Dec 05, 2024

Severity: 3-Major

Symptoms

After performing an upgrade from a version lower than 16.0 to a version higher or equal to 16.0, BIG-IP will fail to establish LACP trunk when interfaces are configured in virtual-wire mode. Version 16.0 introduced transparent LACP bridging of LACP allowing LAG to be established across BIG-IP. This feature is enabled by default in versions > 16.0.

Impact

Fail to establish LACP trunk.

Conditions

- Trunk configured with LACP. - Virtual-wire configured across the trunk. - Upgrading from version lower than 16.0 to a version higher or equal to 16.0.

Workaround

Setting l2.virtualwire.multicast.bridging to disabled allows BIG-IP to establish LACP directly with other devices without bridging maintaining the behavior from versions < 16.

Fix Information

None

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips