To make all internal computers use OpenDNS you would have to:
- Go to IP > DHCP Client, uncheck the checkbox to use peer dns so that Mikrotik doesn’t use the DNS servers provided by your ISP
- Go to IP > DNS, allow remote requests. By default the firewall should block input requests from the WAN, which means only internal clients can query the Mikrotik for DNS.
- In that window, set your OpenDNS server IPs in the ‘servers’ field.
- Go to IP > DHCP Server > Networks, edit the only entry and set the DNS Server to hand out to be that of your Mikrotik LAN IP. 192.168.88.1 unless you changed it.
- Optionally create an IP > FIrewall rule, block FORWARDed packets from going out the WAN on udp port 53. This prevents internal computers to query anything but your router.
Know how to accomplish these steps?
Alternative option, if Windows, set the OpenDNS servers on your network interface directly. Then create a non-admin user for the kids. Non-admins can’t change DNS server settings.