Bug ID 783113: BGP sessions remain down upon new primary slot election

Last Modified: Oct 16, 2023

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

Known Affected Versions:
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, 11.6.0, 11.6.1, 11.6.2, 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, 12.0.0, 12.0.0 HF1, 12.1.0 HF1, 12.0.0 HF2, 12.1.0 HF2, 12.0.0 HF3, 12.0.0 HF4, 12.1.1 HF1, 12.1.1 HF2, 12.1.2 HF1, 12.1.2 HF2, 12.1.0, 12.1.1, 12.1.2, 12.1.3, 12.1.3.1, 12.1.3.2, 12.1.3.3, 12.1.3.4, 12.1.3.5, 12.1.3.6, 12.1.3.7, 12.1.4, 12.1.4.1, 12.1.5, 12.1.5.1, 12.1.5.2, 13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1, 13.1.0, 13.1.0.1, 13.1.0.2, 13.1.0.3, 13.1.0.4, 13.1.0.5, 13.1.0.6, 13.1.0.7, 13.1.0.8, 13.1.1, 13.1.1.2, 13.1.1.3, 13.1.1.4, 13.1.1.5, 13.1.3, 13.1.3.1, 13.1.3.2, 13.1.3.3, 13.1.3.4, 14.0.0, 14.0.0.1, 14.0.0.2, 14.0.0.3, 14.0.0.4, 14.0.0.5, 14.0.1, 14.0.1.1, 14.1.0, 14.1.0.1, 14.1.0.2, 14.1.0.3, 14.1.0.5, 14.1.0.6, 14.1.2, 14.1.2.1, 14.1.2.2, 14.1.2.3, 14.1.2.4, 14.1.2.5, 14.1.2.6, 14.1.2.7, 14.1.2.8, 14.1.3, 15.0.0, 15.0.1

Fixed In:
15.1.0, 15.0.1.1, 14.1.3.1, 13.1.3.5, 12.1.5.3, 11.6.5.2

Opened: May 17, 2019

Severity: 3-Major

Symptoms

BGP flapping after new primary slot election.

Impact

BGP goes down. BGP flaps cause route-dampening to kick-in on the BGP neighbors.

Conditions

--- A BFD session is processed on a secondary blade. (It can be identified by running tcpdump.) -- After a primary blade reset/reboot, the BFD session should be processed by the same tmm on the same blade, which was secondary before the primary blade reset/reboot. -- The BFD session creation should happens approximately in 30 seconds after the reset/reboot.

Workaround

There is no workaround, but you can stabilize the BIG-IP system after the issue occurs by restarting the tmrouted daemon. To do so, issue the following command: bigstart restart tmrouted

Fix Information

BFD no longer remains DOWN after a blade reset/reboot. There is a convergence period caused by blade changes(blade reset/reboot, new blade installed, blade comes up), which may take a few moments, but after that BFD sessions show correct status.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips