When setting up a network, just getting a good ISP is never enough, since, when in a network, there are several ways you can speed up the performance. One of these ways, which is now almost a general practice, is to use a DNS forwarding server.
DNS Forwarding
DNS forwarding is the service that you should resort to if you need to speed up the DNS name resolution process. It is very useful in cases when a request for a domain name is sent by the user but the DNS server, responsible for converting the name into its corresponding IP address, can't locate the matching IP address in its cache and its zones of authority. Via the forward-DNS-resolution-request functionality the queries for a specific non-resolvable address can be directed to alternative name servers.
Using DNS forwarding can be of help to individuals and companies with large namespaces. It could also help collaborating companies resolve each other's namespace to ensure and even accelerate the DNS resolution process in case one of the companies has any resolving problems.
How does DNS forwarding work
When you set up your internal network and make a DNS query, if there is no DNS forwarder, the root hints of the DNS query server will be publicly transmitted online, which can cause a big security problem if the internal DNS information is private. Also, this can lead to a large external traffic, which can be costly if the prices of the current ISP provider are high or if the connection is slow.
When you have a DNS forwarder set up, it will be responsible for the external traffic. The forwarder will quickly build a large internal cache of external DNS data, and using the cached data, it will reduce the DNS traffic to a minimum.