My current setup is firewall nat same... but I am looking for solution to do some kind of dynamic nat.
Problem is that users have static ip on the network (no pppoe or hotspot).
No more then 1k users at the same time on the network.

I was thinking about mangling users first connection to access list, then to make nat from addres list to IP from pool.

Did someone try to do this ?

http://forum.mikrotik.com/viewtopic.php?f=2&t=55823

Posting the same question multiple times is kind of frowned upon.