In some embodiments, a method stores domain name system (DNS) resolution mappings from a domain name to an address in a first table. The DNS resolution mappings are intercepted from DNS responses being sent by a DNS server. The first table is sent to a manager for validation of the DNS resolution mappings. Then, a second table is received from the manager that contains validated DNS resolution mappings. The method intercepts a DNS response that includes a domain name to address resolution mapping from the DNS server and validates the domain name to address resolution mapping using a validated DNS resolution mapping in the second table.