SprintLink provides free Primary DNS for up to 5 second-level domains i.e. customer.com and free Secondary DNS for up to 50 zones on a per customer basis. DNS is supported for IPv4 and IPv6 protocols If a customer needs Primary DNS for more than 5 second-level domains, the customer should contact his/her sales representative for pricing and ordering. Further, if a customer needs Secondary DNS for more than 50 zones, the customer should contact his/her sales representative for pricing and ordering.