I have a problem w. one of the computers on my LAN. With the settings unchanged, it can no longer get on the Internet, get email, or see any other 'putas on the LAN. If I disable the auto IP addy setting and assign it an IP addy like 192.168.1.104 (according to IPSCAN my main puta is x.100, computer B is 101, computer C is 102 and computer D is 103), it can see the other 'putas on the LAN, but not the Internet.
In general, only computers which are acting as servers to the outside world need a static IP address assignment. Most computers should have their IP address assigned automatically. On these computers, the network connection should be set to both of these settings:
Obtain an IP address automatically
Obtain DNS Server address automatically
This will let your router's DHCP server assign the computer an IP address and also tell it where to find a working DNS server (usually at the ISP).
The router will also tell your computer the address of the default gateway to the internet (usually the router itself) and the subnet mask (which defines the extent of your local network; it's usually 255.255.255.0).
To see if your computer is set up to obtain an IP address and DNS server addresses automatically, open the Control Panel and click on Network Connections.
Look for your Local Area Network Connection and double-click on it. You'll get a popup labeled Local Area Connection Status. On the lower left of the popup will be a button labeled Properties. Click that.
Now you'll get a popup labeled Local Area Connection Properties. In the middle of the popup is a window. Scroll down to the bottom and double-click on Internet Protocol (TCP/IP).
Now you'll have an Internet Protocol (TCP/IP) Properties popup. To have your router assign your computer its IP address and other information, make sure both these radio buttons are clicked:
(o) Obtain an IP address automatically
(o) Obtain DNS Server address automatically
Click OK to close the popups.
If you can see other computers on your LAN but not anything on the internet, this means your computer's hardware connection to your router is ok. This is good!
So what's the problem? Most likely either your computer is not getting a DNS server assigned to it or it's not assigned to the correct address for its default gateway (generally the internal IP address of your router).
To see if the gateway is working, try pinging a computer out there somewhere in the internet. Open a DOS Command prompt (Start -> All Programs -> Accessories -> Command Prompt) and type this:
ping racesimcentral.com
You should get something like this:
C:\Documents and Settings\Alison>ping racesimcentral.com
Pinging racesimcentral.com [217.75.102.168] with 32 bytes of data:
Reply from 217.75.102.168: bytes=32 time=157ms TTL=112
Reply from 217.75.102.168: bytes=32 time=159ms TTL=112
Reply from 217.75.102.168: bytes=32 time=159ms TTL=112
Reply from 217.75.102.168: bytes=32 time=159ms TTL=112Ping statistics for 217.75.102.168:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 157ms, Maximum = 159ms, Average = 158ms
If ping resolves racesimcentral.com into an IP address (217.75.102.168 in this case) then your computer is talking to a DNS server.
If it doesn't, try pinging an IP address directly:
C:\Documents and Settings\Alison>ping 217.75.102.168
Pinging 217.75.102.168 with 32 bytes of data:
Reply from 217.75.102.168: bytes=32 time=158ms TTL=112
Reply from 217.75.102.168: bytes=32 time=159ms TTL=112
Reply from 217.75.102.168: bytes=32 time=157ms TTL=112
Reply from 217.75.102.168: bytes=32 time=157ms TTL=112Ping statistics for 217.75.102.168:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 157ms, Maximum = 159ms, Average = 157ms
If that fails too, then you probably don't have a gateway being assigned properly. Check the Local Area Connection as described above and make sure both radio buttons for obtaining IP and DNS addresses are checked.
If pinging the IP address directly works but pinging the domain name didn't, then your computer isn't talking to a DNS server. Check the Local Area Connection as described above and make sure the radio button for obtaining DNS server addresses is checked.
If you want to try assigning a static IP address, you will have to assign not only a local IP address, but also the default gateway, the subnet mask, and at least one (preferably two) DNS server addresses.
First, pick an address from outside the range that is being assigned by the router's DHCP server. Make sure no other computers on your LAN are using it.
Next, go to another computer and open its Local Area Connection Properties popup. Open its TCP/IP Properties popup (see above) and write down all the other info that it is being assigned, including subnet mask, default gateway, and DNS Servers.
Now go back to the computer with a problem and open the Local Area Connection as described above. Put all this information into the Local Area Connection Properties for TCP/IP, along with the IP address that you picked for this computer.