you're the second (if I'm counting correctly) person able to reproduce this. So far we do not know what is causing this, and all tests we made so far cannot reproduce this. Previous unlucky user had problem, that he had less available macs in MAC pool, than actual nics in system. This does not answer the question how he was able to reach this situation, but he was able to greatly reduce this issue via making MAC pool bigger.

You said, that you added extra pool. Which pool are you referring to? MAC pool? VM pool? Please describe your environment and ideally provide us with logs. How many VMs do you have in each VM pool? How many vm_interfaces do you have in your system in total? How many MAC pools do you have in your system and what is its configuration?

thanks,

Martin.