Symptoms
The rate shaper used for BIG-IP virtual Edition (VE) divides the total licensed throughput amongst the running TMMs to determine a per-TMM throughput. If the TMM count is greater than the licensed throughput, then this causes a 0-per-tmm throughput limit, which is unfortunately used as a divisor later in rate shaper operations, and which might result in an eventual divide-by-zero error and a crash. This might repeat indefinitely.
Impact
Traffic is disrupted while TMM restarts, potentially repeatedly.
Conditions
Install a license on a VE with a bandwidth limit where the number of megabits per second (Mbps) is less than the number of TMM instances (typically, the number of CPU cores), for example, Use a 2 Mbps license and configure 4 CPUs on a VE system.
Note: This has been observed on evaluation licenses, but might be possible in other circumstances.
Workaround
Change the number of vCPUs available to the BIG-IP guest to be less than the licensed throughput.
Fix Information
Rate shaper now enforces a minimum, per-TMM throughput to avoid dividing by zero and crashing when the TMM count is greater than the licensed throughput in Mbps.
