In this scenario, BIND does not store zone information of any kind, instead, it simply forwards all name resolution requests to a designated nameserver located elsewhere. This way, BIND configuration and maintenance is minimal while name resolution traffic is optimized: BIND caches resolved name-to-IP address mappings, thereby saving some bandwidth and improving name resolution speed.

This setup is especially recommended for small to medium-sized networks where DNS zone information of the company is maintained off-site, typically at an ISP, and thus maintaining a dedicated nameserver only for Internet name resolution is not economical.

In this setup BIND operates essentially as a DNS proxy.

In this setup two sets of records on the DNS server are maintained:

With this setup it is possible for a company to both maintain its own public DNS zone records (SOA, NS, MX and A records for hosts running popular services like WWW or FTP) and some internal DNS records for servers that are (and must be) available for internal users only.

This setup is recommended for companies wishing to host their own DNS zone database but the number of external name resolution requests does not facilitate the use of a dedicated DNS server.