MAC table does not contain any entries

I have setup some virtual servers and they are load balancing traffic as expected. I see the ARP table on the F5 being updated with the expected entries. But, the MAC (L2) table remains empty. I'm not sure why this is.

 

In the ARP table, an IP address is associated with a next hop VLAN interface. However, if that VLAN interface is backed by multiple physical interfaces, does the F5 broadcast traffic to the physical interfaces? I don't see any MAC learning occurring.