My devices get their dns servers via DHCP. So I enter it only once on the DHCP server. If you’re running so many devices, you probably want to use your own DNS

My devices get their dns servers via DHCP. So I enter it only once on the DHCP server. If you’re running so many devices, you probably want to use your own DNS server too (for internal name resolution), so you can also set the upstream just there.