A method and system for providing service over a communication network. The method includes establishing a plurality of virtual DNS servers that is supported by a DNS server. A plurality of target IP addresses is assigned for the plurality of virtual DNS servers. Each target IP address includes a first IP subaddress identifying the DNS server, and a second IP subaddress identifying a corresponding virtual DNS server. A plurality of network capable devices is uniquely assigned to the plurality of virtual DNS servers for domain name resolution. Each network capable device accesses the communication network through a corresponding network device associated with a corresponding source IP address. A service plan of a client is assigned to a first network capable device used by the client. The service plan is implemented through a DNS request under a session established between the first network capable device and its assigned first virtual DNS server. The session is uniquely identified by a combination of a first source IP address of a first network device used by the first network capable device to access the communication network, and a first target IP address of the first virtual DNS server.