Communicating additional information in a DNS update response by requesting deletion of a specific record

In a Domain Name System (DNS) server, a method for responding to a DNS message, the method comprising:

• receiving the DNS message from a requesting device;
• generating a search result based on a search of a portion of the DNS message for a request to delete a specific record;
• and
• selectively providing and not providing current state information to the requesting device depending on whether the search result indicates that the request to delete the specific record resides within the portion of the DNS message;
• wherein generating the search result includes inspecting an update section of the DNS message for a request to delete a specific record, the update section being different than (i) a header section configured to identify the DNS message as an update message, a zone section configured to denote a zone of records being undated;
• and (iii) a prerequisite section configured to contain a set of prerequisites which must be satisfied upon receipt of the DNS message;
• and
• wherein:
• inspecting the update section of the DNS message includes outputting a result signal having a first value when the update section includes a command to delete a predefined resource record from a predefined resource record set and a second value when the update section does not include a command to delete a predefined resource record from a predefined resource record set, the second value being different than the first value;
• selectively providing and not providing current state information to the requesting device depending on whether the search result indicates that the request to delete the specific record resides within the portion of the DNS message includes:
• if the result signal has the first value, then sending a reply message to the requesting device in response to the DNS message, the reply message including current state information;
• and
• if the result signal has the second value, then sending a reply message to the requesting device in response to the DNS message, the reply message being without the current state information;
• and
• wherein the command to delete a predefined resource record is a command to delete a specific resource record which is not expected to exist in the DNS.

A Domain Name System (DNS) server, comprising:

• an input;
• an output;
• and
• a controller coupled to the input and the output, the controller including:
• means for receiving, through the input, a DNS message from a requesting device,
• means for generating a search result based on a search of a portion of the DNS message for a request to delete a specific record, and
• means for selectively providing and not providing, through the output, current state information to the requesting device depending on whether the search result indicates that the request to delete the specific record resides within the portion of the DNS message;
• wherein the command to delete a predefined resource record is a command to delete a specific resource record which is not expected to exist in the DNS