specific dns for specific ip

RouterOS Beginner Basics
1

Hello friends.
I have configured in my home network, that all users in network use OPEN DNS 8.8.8.8
which i did through DHCP Server.
To Block bad sites for specific user i want to use filtered dns 208.67.222.222 and 208.67.220.220.

So, Is there a way to restrict specific users to use the DNS i specified in DHCP Server.
I mean Even if they assign DNS manually my preferred DNS in Mikrotik should override.
Many Thanks

2

you can use NAT for this, but first you need add client ip in address list if you want add too filtered dns, next you can use this rule

/ip firewall nat
add action=dst-nat chain=dstnat comment=OpenDNS dst-port=53,5353 protocol=udp \
    src-address-list=opendns to-addresses=208.67.222.222 to-ports=5353
add action=dst-nat chain=dstnat comment=OpenDNS dst-port=53,5353 protocol=udp \
    src-address-list=opendns to-addresses=208.67.220.220 to-ports=5353

make sure that rule in the top after masquerade rule, and dont forget add client ip on opendns address list