Managing domain name system (DNS) record cache across multiple DNS servers using multicast communication

A non-transitory machine-readable storage medium that stores instructions, that when executed by a processor of a Domain Name System (DNS) resolver node causes said processor to perform the operations comprising:

• receiving a first DNS query from a first client device;
• determining that an answer to the first DNS query cannot be currently generated using a cache local to the resolver node, wherein the resolver node is one of a plurality of resolver nodes that each are part of a same multicast group;
• performing a recursive query with a set of one or more other authoritative nameservers to obtain a first answer to the first DNS query, wherein the first answer includes a first set of one or more DNS resource records;
• storing the first set of DNS resource records in the cache local to the resolver node;
• transmitting the first answer to the first client device;
• transmitting a first message to a multicast interface in which each of the plurality of resolver nodes are listening, the first message including the first set of DNS resource records;
• receiving a second message on the multicast interface from one of the other of plurality of resolver nodes, the second message including a second set of DNS resource records;
• determining that the second set of DNS resource records included in the second message is not included in the cache local to the resolver node;
• storing the second set of DNS resource records in the cache local to the resolver node;
• receiving a second DNS query from a second client device;
• determining that the stored second set of DNS resource records in the cache local to the resolver node answers the second DNS query;
• generating a second answer to the second DNS query using the stored second set of DNS resource records in the cache local to the resolver node;
• and
• transmitting the generated second answer to the second DNS query to the second client device.

A Domain Name System (DNS) resolver node, comprising:

• a processor;
• and
• a non-transitory machine-readable storage medium that provides instructions that, when executed by the processor, causes the resolver node to perform operations comprising:
• receive a first DNS query from a first client device;
• determine that an answer to the first DNS query cannot be currently generated using a cache local to the resolver node, wherein the resolver node is one of a plurality of resolver nodes that each are part of a same multicast group;
• perform a recursive query with a set of one or more other authoritative nameservers to obtain a first answer to the first DNS query, wherein the first answer is to include a first set of one or more DNS resource records;
• store the first set of DNS resource records in the cache local to the resolver node;
• transmit the first answer to the first client device;
• transmit a first message to a multicast interface in which each of the plurality of resolver nodes are listening, the first message to include the first set of DNS resource records;
• receive a second message on the multicast interface from one of the other of plurality of resolver nodes, the second message to include a second set of DNS resource records;
• determine that the second set of DNS resource records included in the second message is not included in the cache local to the resolver node;
• store the second set of DNS resource records in the cache local to the resolver node;
• receive a second DNS query from a second client device;
• determine that the stored second set of DNS resource records in the cache local to the resolver node answers the second DNS query;
• generate a second answer to the second DNS query using the stored second set of DNS resource records in the cache local to the resolver node;
• and
• transmit the generated second answer to the second DNS query to the second client device.