Only if you know with certainty that the updates get sent only to a local DNS server should you run the Dynamic DNS Updates service.
Most home users who use DSL/Cable routers as DHCP/NAT servers to facilitate multiple host connections to the Internet should turn off dynamic DNS updates.
However, in many cases when the DHCP and DNS configurations have inconsistencies, the LDNS may direct the DHCP client to a place outside the local scope, resulting in leakage of private DNS updates to the global network.
While this service can reduce administrative overhead, it also can, and does, have deleterious effects on the larger Internet by leaking traffic regarding private IP addresses that should never leave the local area network.
The default configuration not only wastes global Internet resources but also introduces a multitude of security, privacy and intellectual property concerns.
Leakage of private DNS updates is caused by inconsistent configuration between DNS servers and DHCP client/server entities.
``So what if my host leaks a few packets to the global Internet? '' The reason is that inconsistent configuration between your home hosts and your local DNS servers can, and often does, cause leakage of DNS updates for private IP addresses to the global Internet.
This leakage causes the following problems: Unfortunately, most users have no knowledge of their own misbehaving hosts broadcasting private information to the world.
Microsoft Windows operating systems support a feature that dynamically updates the mappings of domain names to associated IP addresses assigned to hosts by DHCP servers.
This automatic updating, called Dynamic DNS Updates service, reduces the administrative overhead associated with manually administering DNS records of network hosts.