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.
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.
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.
In the example shown above, the LDNS is not configured with a local zone for 168.192.
The following steps only illustrate how to turn off dynamic DNS updates on Microsoft Windows systems.
For Linux or Free BSD systems that use ISC's DHCP client and server software, the dynamic DNS update feature gets set to off by default and requires manual intervention to turn on the 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.The LDNS thus iteratively sends the SOA request, starting with a root DNS server, and eventually returns the server (step 8).Over 97% of DNS updates that leak onto the global Internet come from Microsoft Windows operating systems (see companion paper on The Windows of Private DNS Updates).When you make a DNS change, it takes time for the changes to take effect. It is the time it takes for the domain DNS to refresh the cache on the network.The cache is cleared over a certain amount of time.
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.