list of free DNS that you can use,
Google Public DNS
Primary server: 126.96.36.199
Secondary server: 188.8.131.52
Google operates the world’s largest public DNS service. Launched in December 2009, it supports many billions of DNS queries per day, much of the volume generated from clients outside the U.S. The company developed this service as one of its corporate initiatives to make the Internet more accessible and easier for everyone to use, making it a logical choice for users worldwide.
Primary server: 184.108.40.206
Secondary server: 220.127.116.11
The oldest of all services on this list, OpenDNS also supports billions of DNS queries per day. In addition to its basic name resolution service, OpenDNS Home Solutions provides free Web site filtering of adult content (called FamilyShield) and URL spell correction with accompanying installed software. The company also sells various security products to businesses. Those looking for an alternative to Google products and a service that works well outside the U.S. also tend to like OpenDNS.
Secondary server: 18.104.22.168
Comodo Secure DNS
Secondary server: 22.214.171.124
Secondary server: 126.96.36.199
Secondary server: 188.8.131.52
Verizon / Level 3 CommunicationsU.S Internet provider
Secondary server: 184.108.40.206