The DNS servers for your local Internet service provider could block access to our ad servers or they do not resolve the domain name to the correct IP addresses.
What is a nameserver?
Nameservers are used by ISPs (eg: Comcast, Time Warner, AOL, Yahoo, AT&T, etc.) to map hostnames (eg: www.adspeed.com) to IP addresses (eg: 127.0.0.1). If a nameserver server has problems, users of these servers will experience connection problems to any/many websites. In Firefox, the error message is normally "Server Not Found". When this happens, visitors using another working nameserver would be able to access the websites normally.
Problem Identification
The following 2 images are the same file but use 2 different methods for access, one uses hostname and one uses a direct IP address.
Standard (Hostname)
IP Addresses
If you can see both images, your ISP's DNS servers seem to work properly. Otherwise, you might have an isolated problem seeing ads served by AdSpeed. To verify that your ISP nameservers are causing accessibility problems, you could ping our server or perform a nameserver lookup on g.adspeed.net. To do this in Windows:
- Click on Start/Run and type "cmd"
- When the command-line window appears, type "ping g.adspeed.net"
- And perform a lookup of hostname "nslookup g.adspeed.net"
Solutions
If the ping/nslookup results contain any error message or show some packet loss, you should contact your ISP and ask if they have or know of any issue with their nameservers or network. Or you can try to use another DNS server, we hear great things about
OpenDNS
Troubleshooting 
