InetDaemon.Com

Check the physical and data link layers first.

1. Is the network cable plugged in?
2. Is it the right kind of Network cable?
   1. Host to Switch/Hub - Straight through cable
   2. Switch/Hub to Switch/Hub - Crossover cable
   3. Router to Switch/Hub - Straight through (routers actually are treated as hosts)
3. Check the link light
   1. Is it on and solid green? With Ethernet, a solid green light usually means there is connectivity.
   2. Is the light blinking in a regular pattern of on-off-on-off? This means the network card is not able to communicate and there is a physical problem.
   3. Is the light on, but amber? On 10/100 Tx Ethernet cards an amber link light means the card is operating ant 10mbps. If the network is 100mbps, you won't be able to communicate.
4. Check your Speed setting
   1. Ethernet networks of different speeds are not compatible.
   2. Find the lowest-speed device, reconfigure all devices to run at that speed.
   3. Verify all hubs and switches are the same speed as the network cards
   4. You may have to set the speed manually on the switch and the computer
5. Check your duplex setting
   1. Devices with incorrect duplex settings will generate CRC and framing errors.
   2. You may have to set the duplex on the switch and the computer manually.
6. Make sure you have the correct driver loaded and that the latest driver version is installed.
   1. The driver may have crashed, try rebooting the computer to correct the issue.
   2. If the wrong driver is loaded, you won't be able to connect to the network.
   3. Wrong version of the driver will cause auto-detection problems or other errors.