Patent ID: 7930428

Claim:
A computer executed method for adapting a processor from computer readable media to operate a domain name system (DNS) server apparatus resistant to cache poisoning comprising the following steps: receiving, at a DNS server, a domain name system (dns) request from a resolver; replicating the dns request; generating a transaction id and source port for a first dns request using a first pseudo-random algorithm and generating a transaction id and source port for a second dns request using a second pseudo-random algorithm; transmitting one of the replicated dns requests to a primary server and an other replicated dns request to at least one secondary server; blocking a first DNS reply to the resolver until a plurality of DNS replies are received; receiving a reply from each of at least two dns servers; comparing the reply Internet Protocol (IP) address from a first dns request with the reply from a second dns request; and responding to the resolver on the condition that two dns IP address replies match.