Last Modified: Oct 16, 2023
Known Affected Versions:
14.1.0, 18.104.22.168, 22.214.171.124, 126.96.36.199, 188.8.131.52, 184.108.40.206, 14.1.2, 220.127.116.11, 18.104.22.168, 22.214.171.124, 126.96.36.199, 188.8.131.52, 184.108.40.206, 220.127.116.11, 18.104.22.168, 14.1.3, 22.214.171.124
Opened: Nov 29, 2018 Severity: 3-Major
There are three major routing participants on a BIG-IP system: TMM, ZebOS, and Linux routing tables. Each of them replicates routes between the other. The 'bigstart restart tmm' command restarts tmm, and a part of the restart process is to mark VLAN interfaces DOWN and later UP. Another part the same process is to restart the ZebOS daemons. There is a race condition between these two events, so the following might happen: 1) tmm marks interface named vlan1 as DOWN, and a bit later marks as UP, but not UP and RUNNING. 2) The ZebOS daemons are restarted and ready to update interface status. They request a current status and mark interface UP, not UP and RUNNING. 3) tmm is fully restarted and marks vlan1 UP and RUNNING. 4) The ZebOS daemons reject dynamic routes because interface vlan1 is UP, but not RUNNING.
Traffic which relays on dynamic routes is interrupted. Because this is a race condition, it depends on configuration and timing.
- BIG-IP Virtual Edition (VE). - Dynamic routing is configured and there is a decide with some dynamic routes. - You run the 'bigstart restart tmm' command.
Restart tmrouted daemon using the following command: bigstart restart tmrouted
Dynamic routes are not rejected and are successfully inserted into routing tables.