Technical Information
Prev
Next

Chapter 5. Technical Information

In the first section of this chapter, you'll find some valuable information about networking basics. In the second, all configuration files on your disk which can be changed by KNetworkConf will be discussed.

IPv4 Networking

This section cannot be a replacement for further lecture of IP-Networking. In this appendix, you'll only find the basic informations to get you started integrating your machine into a small (home) network.

Currently, IP-networking is done using TCP/IP version 4 (IPv4). IPv5 has never been used much. IPv6 is expected to get spread in the near future. So, this manual is based on the currently most spread IPv4.

One of the most important informations for setting up an interface is the IP-address which you have to assign to the interface. In foreign networks, for example, your office, you have to ask the network administrator to tell you a valid IP-address, or you can use DHCP if this is available. In any case, you are not allowed to simply choose any IP-address!

If you want to set up a small (home) network of your own, you should use IP-addresses from a range which has especially reserved for this purpose to prevent IP-address-conflicts with the global (Internet) network. The addresses from the table shown below are not routed in the Internet, so it is save to use them as you like.

Of course these machines can later be configured for Internet access by using a gateway machine.

You can freely use the following addresses:

Table 5.1. IP-Addresses for private networks

ClassRange
A10.0.0.0 to 10.255.255.255
B172.16.0.0 to 172.31.0.0
C192.168.0.0 to 192.168.255.0

For smaller networks, the most often used addresses are these in the range of 192.168.1.1 to 192.168.1.254. This is enough for networks up to over 250 computers.

Furthermore, the netmask is most often set to 255.255.255.0, so that all of these machines are members of the same subnet.

Some addresses are reserved for special things, for example, 0.0.0.0 and 127.0.0.1. The first one is the so called default route, the second the loopback address. The default route is needed by IP routing.

The network 127.0.0.1 is reserved for the IP-traffic which works on the local machine only. Usually, the address 127.0.0.1 is assigned to a special device, the so called loopback interface, which works like a closed circle.

A default gateway is a computer which connects two different networks. If you have configured a small network of your own, it is most likely that you want all (or some) of your machines to grant Internet access. But this is not possible directly, because these machines use local private IP-addresses, which are not routed in the Internet. The solution is a computer which translates between the two different networks. This computer uses at least two interfaces. One of them, maybe an Ethernet card, points to the local network, the other one, maybe an ISDN card, points to the Internet. In this case, both interfaces use different IP-addresses. This computer performs a so called network address translation (NAT, aka IP-forwarding). To enable a local machine the Internet access, you have only to tell them the default gateway, the local IP-address of the gateway-computer.

Prev
Next
Home


Would you like to comment or contribute an update to this page?
Send feedback to the TDE Development Team