How to use the ping command to check your network connection
  • XP- Click on Start, All Programs, Accessories, Command Prompt
    Vista & WIndows 7- Click on Start, All Programs, Accessories. Right click on Command Prompt and select Run as Administrator
  • Type ping www.mozilla.org and press Enter
  • Right click on the command prompt window title bar, select Edit then Mark
  • Use the mouse to select all the output from the ping command, them click the right mouse button. This will copy the data to the clipboard.
  • Start a new post here and paste the data you copied into it.
The output of the ping command should look something like this:

Pinging www-mozilla-org.glb.mozilla.com [63.245.209.11] with 32 bytes of data:

Reply from 63.245.209.11: bytes=32 time=97ms TTL=236
Reply from 63.245.209.11: bytes=32 time=88ms TTL=236
Reply from 63.245.209.11: bytes=32 time=87ms TTL=236
Reply from 63.245.209.11: bytes=32 time=89ms TTL=236

Ping statistics for 63.245.209.11:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 87ms, Maximum = 97ms, Average = 90ms

If ping works (you get responses from mozilla.org) then you have a working internet connection and name resolutions (DNS or Domain Name Server) is also working correctly.

If the ping doesn't work, try pinging the IP address I show in my sample response, since Mozilla.org's IP address should be very stable.

ping [removed]

If this works then you have a working internet connection but you have a DNS (Domain Name Server) problem. Contact your ISP for assistance. A workaround would be to give OpenDNS a try. Directions are here: https://www.opendns.com/homenetwork/start,

If it doesn't work then your internet connection is defective.

Edited 04/30/2011 to add Vista and Windows 7 information.