DD-WRT is an alternate firmware suitable for many routers. For more information about this firmware, read the About Page on the DD-WRT website.
To use OpenDNS on a router with DD-WRT, configure OpenDNS on the router per the OpenDNS best practices. Next, log in to the router configuration page per the device instructions and go to the Services tab. Under Additional DNSMasq Options, type strict-order and Save the new settings. Finally, reboot the router and manage your account settings in the OpenDNS Dashboard.