Is it possible to use mixed DNS servers?

Computer's DNS server is a recursive resolver, typically provided by the local ISP. You can mix use DNS servers from different providers, but people are used to not mixing them.

The computer's DNS is usually automatically obtained by default. If you want to make configuration, it is preferred to set both the primary and secondary DNS to ISP's DNS server, because we are closest to ISP's DNS server, and using the DNS of the network service provider can ensure the smoothness of our network to the greatest extent.

If you want to mix different DNS servers, it is also possible. For example, use ISP's DNS as the primary DNS server, and use 114 DNS as the secondary DNS server, but your network speed may be a little bit slower. However, with the development of technology, at present, some large public DNS service providers can use anycast technology to make network services unaffected by distance.

The domain name DNS server mentioned here refers to the authoritative DNS server. We do not recommend mixing DNS from different providers under the same domain name.

Generally, the working of DNS servers defaults to using secondary/tertiary DNS servers n sequence only when the primary DNS server times out or points to a non-routable IP address. If you mix DNS from different providers, each server needs to perform data resolution, and most routers and systems will randomly choose which DNS server to receive packet, which will cause confusion in the caching rules of the server system and lead to problems in filtering and reporting.

If you desire to use multiple DNS servers, then you must be allowed to edit each DNS server records to keep them consistent. However, according to RFC2182, it is not recommended to use more than seven DNS servers for a domain name, because it may bring a great challenge to the management of DNS records.