I had all sorts of problems with the inbuilt DNS and DHCP functions only being able to use the limited settings and odd things happening.
I ended up allowing the router to use the ISP provided DNS for its own use. Switching off the inbuilt DHCP and using my own DHCP server which allows me to specify whatever I want where I want.
I also use my own DNS servers running locally which I then use forwarders to get to the internet. This setup also means if I lose or have to reset my router, I dont lose all my DHCP/DNS config.
Its the best solution I have found so far, may not be for everyone, but it works.
I ended up allowing the router to use the ISP provided DNS for its own use. Switching off the inbuilt DHCP and using my own DHCP server which allows me to specify whatever I want where I want.
I also use my own DNS servers running locally which I then use forwarders to get to the internet. This setup also means if I lose or have to reset my router, I dont lose all my DHCP/DNS config.
Its the best solution I have found so far, may not be for everyone, but it works.