Am I configuring DNS correctly?

[hwy17]

I think I have two questions:

1. Is configuring dns servers in 'DHCP and DNS' instead of on the WAN interface acceptable/correct?
2. Is adding two ipv6 entries in line after 2 ipv4 entries the correct way to configure "dual stack" dns?

Thanks

[hwy17]

Or is this better?

[openwrtforever]

Second one is the exact one I use on my WRT3200ACM. One for IPv4, and one for IPv6.

[jc1685]

I always use the custom dns servers section in the WAN/WAN6 Advanced settings like you have in your second screenshot.