VMware, Inc.
DNS cache protection

Abstract:

Some embodiments provide a method for detecting that a domain name service (DNS) cache on a data compute node (DCN) has been attacked. The method, during a first operational phase of an agent executing on the DCN, builds a DNS cache that stores entries that include (i) network address to domain name mappings and (ii) policies for the entries received from a centralized service. During a second operational phase of the agent, the method detects that an entry of the DNS cache has been modified by a DNS response such that the modified entry violates the policy for the entry. Based on the detection, the method sends an alert to the centralized service. The centralized service performs additional analysis on the modification to determine whether to allow the DCN to use the modified DNS cache entry.