Disclosed is a self-cleansing intrusion tolerance-domain name systems system comprising at least three DNS servers, at least four storage systems accessible by the DNS servers, a communications link, a message transfer mechanism, and a self-cleansing mechanism. The storage systems include at least three online storage systems and at least one offline storage system. The communications link can connect the DNS servers with the storage systems, as well as connect the DNS servers with a local area network, which can connect the DNS servers with an external network. The message transfer mechanism can rotate the DNS servers into a plurality of roles, including a primary role, a secondary role, a designated role, and a self-cleansing role. The self-cleansing mechanism can be used to perform the self-cleansing role.