This is insane! I spent entire morning on a production network trying to figure out why after upgrade (to stable long term release!) my router does not respond to any DHCP DISCOVER requests. It shows them in log but not sending any offer. Later I found hundreds of “incomplete” arp entries in my core switch. Guess what? Conflict detection feature, that was enabled by default and sending ARP requests to L3 connected switch that relayed dhcp requests from remote segments. Nice Mikrotik. You introduced this “feature” in 6.44: http://forum.mikrotik.com/t/radius-server-not-working-in-2-8-11/127/1 and it still there. Really?