Hi,
I´m newbie in using mikrotik RB750g. Is here someone who can me help with my settings. I need to set on this device 2 different networks. It is not problem, on port2 I have 192.168.0.x network and on port3 I have 10.0.0.x network. But devices in network 192.168.0.x can see devices in network 10.0.0.x. Can I somehow separate this networks? I think that vlan is my solution, but I don´t know how to set it. Sorry for my bad english.
To be sure you get all the traffic, you’ll be better off with firewall rules; I generally find that routerboards (being routers) merrily pass packets between connected VLANs, which most switches (being L2 devices) don’t do.
Simply specify some firewall reject/drop rules in the forward chain with the relevant IP blocks, adding allow rules for any exceptions to the drops (e.g. if the internet gateway is in the other network range).
Dear Discus, many thanks for your reply.
I thought, that vlan would be the best 
So I will try to set the rules on firewall. I hope that I find some kind of how-to. Both of the two networks have the same gateway and the same mask. Is it possible to set it?
Make a firewall rule
Forward chain.
Input ether 2 output ether 3 action = drop
Also the reverse and then the 2 subnets will be isolated
Many thanks it is working. Great.