Described are computerized methods and apparatuses, including computer program products, for network virtualization. An intercept device receives a DNS response message from a DNS server. The DNS response includes a domain name, a network address associated with the domain name, and a destination address of a first network device. The intercept device determines whether the domain name satisfies a DNS intercept criterion. If the domain name satisfies the DNS intercept criterion, then a request intercept criterion is updated to include the network address associated with the domain name. The DNS response message is transmitted on to the first network device by the intercept server.