Hi! I’m trying to setup hotstop access point in ethernet lan of my hostel’s network to provide internet. My router isn’t a default gateway of some subnet. But as you know interfaces owned by hotspot reply on all broadcast arp who-has traffic like all requested addresses are on this router. And router turns ALL subnet traffic by itself. So how can I disable this arp feature?
Don’t know for sure if this will work, but try removing all references to address pools from Hotspots and Hotspot profiles.
A quick test confirms that if you leave the address pool on the Hotspot empty (disabling Universal NAT) the Hotspot no longer ARP poisons the network.
Thank you so much! It’s really works!))
Thanks, fewi. I was looking for that earlier.
May I suggest to the MT crew to modify the wiki to include the warning about Universal NAT and arp poisoning. If a user wishes to allow connections to other localnet users behind the hotspot interface, disable the Universal NAT. Maybe something like this in the manual under hotspot:
address-pool (name / none; default: none) : address space used to change HotSpot client any IP address to a valid address. Useful for providing public network access to mobile clients that are not willing to change their networking settings. However, the Universal NAT uses arp poisoning, so in order to allow localnet computers behind the hotspot interface to communicate with each other, the address-pool should be set to none (disables Universal NAT).
Guys, please help me to solve one more stupid problem 
http://forum.mikrotik.com/t/routing-subnets-with-overlapping-address-spaces/45897/1