Configuring DNS forwarding

When a DNS server gets a query for a resource record (RR) not held by the server, it can use recursion to discover a DNS server that can resolve the RR. If, for example, you use Resolve-DNSName to resolve www.packt.com, the configured DNS server may not hold a zone that would help. Your DNS service then looks to the DNS root servers to discover a DNS server that can via the recursion process. Eventually, the process finds a DNS server that can resolve the RR. Your DNS server then caches these details locally in the DNS server cache.

If you are resolving publicly available names, this process works great. But you might have internally supplied DNS names that the DNS can't resolve via the mechanism. An example might be when two companies merge. There may be internal hostnames (for example, intranet.kapoho.com and intranet.reskit.org) that your organization's internal DNS servers can resolve but are not available from publicly facing DNS servers...