How to Track Down a Problem With DNS Lookup
- 1). Confirm that the network connection and the network device are both available by launching a Web browser and surfing to a popular website. If no other site is reachable, check both the network device itself and the Internet connection.
- 2). Make sure that DNS servers are already configured for your network device by opening a command prompt and typing "ipconfig /all." If no DNS servers are listed, open the network connection properties, select "Internet Protocol Version 4 (TCP/Ipv4)" and click "Properties." In the field labeled "Use the following DNS server addresses:" add the values 208.67.222.222 and 208.67.220.220. Click "OK" and then "OK" again to close the network properties. Try connecting to the target problem server again.
- 3). Use DNS lookup to retrieve the IP address of the target problem server by typing the command "nslookup <target>," where <target> is the fully qualified name of the target server ("www.google.com" rather than "google.com.") If nslookup returns the error "Non-existent domain," then the DNS server may not be configured correctly or the target address may be incorrect (or simply typed incorrectly.)
- 4). If nslookup returned an IP address for the target server, check to see if that server is available by typing "ping <target>," where <target> is the fully qualified name of the target server. A "could not find host" error indicates that the problem is with the target server and not DNS lookup. Contact the technical support people for the problem server.
- 5). Check to see if DNS lookup works for other target addresses by typing "nslookup www.google.com." If nslookup returns IP address information for Google's servers but not the target server, then the error is likely with the way the target server's system administrators configured their DNS records. The best way to address this is to contact the technical support people for the problem server.
- 6). If the DNS lookup works for neither a popular address like www.google.com nor the target server, then the problem is likely the DNS servers the computer is configured to use. Open the network connection properties, select "Internet Protocol Version 4 (TCP/Ipv4)" and click "Properties." In the field labeled "Use the following DNS server addresses:" add the values 208.67.222.222 and 208.67.220.220. Click "OK" and then "OK" again to close the network properties before testing the target problem server again.
