Windows XP - The optimal configuration of your router

The terms "DNS", "Gateway" and "IP" you will probably have heard - but what do they mean? And what do they have to do with a router? I will now try to explain these and other questions to you.

"DNS server" & "IP address":

All computers that are connected to a network have a number that uniquely identifies them. A distinction is made between private and public IP addresses. Every computer that dials into the Internet is given a public address such as 217.230.23.3. A private IP number is intended for networks that are not directly on the Internet, such as small home networks and similar. The following address range is suitable for a private network: 192.168.0.X - 192.168.0.X. Every computer in your home network should have an IP in this address range. In most cases, the IP 192.168.0.1 is already occupied by the router!

Now the question of the DNS server remains. We now know that every computer on the Internet is addressed via its IP address. But then why don't you have to enter http://212.227.127.81/ enter to www.windows-tweaks.info to reach ?

This is where the DNS server comes into play. The task of a DNS server is to make your life easier. It is much easier to, for example windows-tweaks.info notice when the IP address of the server on which the Windows Tweaks homepage is located. If you enter www.windows-tweaks.info in your browser, a request is sent to a DNS server which returns the IP of the server on which the homepage is located to your browser.

If you want to find out for yourself which homepage is on which server, or simply want to test whether you have a connection to a DNS server, you can check this as follows:

Click on Start/Execute and enter cmd (under Windows 98/Me: command). Now type ping www.windows-tweaks.info in!

You will see an IP address in brackets after the homepage. Here in the example is the address of windows-tweaks.info 212.227.127.81. However, if you try http://212.227.127.81 now, you will find that it does not work. This is the case with many websites: This is simply because most Internet servers do not use the standard port for web servers. And now to the subject of the gateway:

"Gateway:

Simply put, a gateway is a computer or hardware router that connects two networks. In the following case, a home network is connected to the Internet. Here is a picture to illustrate it:

In this picture, the address range for the private networks has been chosen differently than in the examples above - I hope you don't mind.

In this picture we see 3 blue marked computers. 2 computers act as gateways and connect a private network to the Internet.

Network settings under Windows 2000/WinXP/Win2003 Server:

So, now you come to the most important part of this article, the settings:

1. The properties of the Network environment call:

2. The properties of the LAN connection open:

3. The properties of the TCP/IP Select protocol:

There are now 2 options for setting the DNS server:

In the 2nd variant, you specify the router as the DNS server. Above, however, you learned that DNS servers must have huge memory to store many Internet addresses - but a router does not have this. When the router receives a DNS request, it automatically forwards it to the provider's DNS servers. Not all routers support this, so the 1st method is the safest.

1st possibility:

2nd possibility:

The DNS servers shown in the picture above are very reliable servers from T-Online that anyone can use.

Router security and common "problems":

I don't want to tell you how everything works in detail, but a few basics are necessary to understand the security behind a router and to be able to solve the associated problems. (Best example of a "problem": eMule LowID)

The best way to imagine routing is like this: Imagine your computer as a gate and your applications, such as eMule and a web server, should run behind this gate. Assume the following scenario: You have a network with a router that is set up as shown in the picture above (below). Your router has the IP 192.168.1.5. Here is the picture again:

Assume that the WebServer is running on the computer with the IP 192.168.1.4. Your friend with the IP 116.32.33.34 now tries to access the WebServer. But, it does not work! Take a look at the drawing: Your friend is accessing your public IP 188.1.2.3. The question now is: Where does he end up? The answer is simple: On the router - but as the router cannot be accessed from the outside for security reasons, your friend receives an error message and cannot connect. Most people think that eMule only needs to connect to the outside world, but this is not true. eMule waits for connections from the outside and can only get a LowID without these connections. The trick now is to tell the router that it should forward the connections to eMule to the computer with eMule. How exactly this works always depends on the application and is not covered here, as I just wanted to give a brief explanation of what is behind some of the "problems". Further information can be found here.

This guest article was created by Al Capone (from the Windows-Tweaks forum), to whom I would like to say a big thank you for his efforts!

NOTE FOR NEW PUBLICATION: This article was produced by Sandro Villinger and comes from the Windows Tweaks archive, which has been built up since the late 1990s.