Not using the DNS from your ISP is always a good practice and here is why.
Changing the DNS on your router is more convenient, as all devices connected to it within your network will be using the 3rd party DNS.
System Trayand select
Open Network and Sharing Center>
Change adapter settings. Alternatively, you can open
Network and Internet>
Network and Sharing Center>
Change Adapter Settingsor you can open the Start menu and search for
view network connections
Internet Protocol Version 4 (TCP/IPv4)
Use the following DNS server addressesand add the public DNS server(s) you want to use.
DNStab, add the public DNS server(s) you want to use, press the Enter key to add them.
Static DNS. It is recommended to use 3.
Use DNSMasq for DNS.
Static DNS. On Tomato Advanced, change
Allow DNS server list to be overridden by DHCP/PPP on WANmust be unchecked
Do not use the DNS Forwarder as a DNS server for the firewallmust be unchecked
On any other router, regardless of brand/model, the DNS settings are usually found in Network Settings or DHCP Settings.