As distinct from various nameserver daemons, software, or appliances (which we'll look at later in Chapter 8, Quasi-Record Types), nameservers can be typed into two broad categories defined by what kind of function they are fulfilling.
Most of the issues we examine in this book are concerned with running DNS operations for a portfolio of domain names and making sure that anybody and anything that queries our domain names always, reliably, obtains a valid response. Doing that involves both main types of nameservers.
The two main functional variations are as follows:
- Resolvers or recursors
- Authoritative nameservers
Resolvers or recursors make DNS queries on behalf of their clients and relay the responses back to those clients.
Authoritative nameservers hold zone data for their client domains or zones and reply to queries coming in for those zones...
