IP addresses: A brief introduction (IPV4 only)An IP address is like a postal address: It allows you to receive messages from the world, and when you want to send somebody a letter, you write on the envelope the destination address.
Computers use the same paradigm, and a computer address is called an IP (Internet Protocol) address. In real it's a bit more complicated but for basic explanation, we stay with this initial metaphor.
Today, there are two versions of IP addressing:
-The oldest one called IPV4, coded with 32 bits, allowing around 4.3 billion addresses. This protocol is the widest in use, even if it is completely saturated today (no more free IPV4 addresses available)
-The new one called IPV6, coded with 128 bits, allowing a much much larger number of addresses (2 to the power of 128)
Most modern computers allow to manage at least IPV4, and for not too old versions of computer Operating Systems, also IPV6; Both can be active at the same time.
The CS2 uses an IPV4 address scheme, and for a computer to be able to communicate with the CS2, they both need to have the same kind of addresses i.e. IPV4
An IPV4 address is composed of 4 bytes : The common notation is A.B.C.D.
Each letter represents a number. The range of the numbers is the same for each letter, i.e. between 0 and 255 inclusive.
Example : The "google-public-dns-a.google.com" DNS server has IPV4 address 8.8.8.8
Among the 4.3 billion addresses, some are reserved for special use.
If you have many computers in your company for various purposes, most of them are not directly reachable from the Internet, even if they can browse the Web.
All these hidden computers from the Internet are connected together thru a Hi-speed LAN (Local Area Network) - a LAN may be very large, allowing thousands of computers -, and some special computers inside the LAN plays the role of gateways, allowing access to (and sometimes from) the Internet.
IPV4 protocol has some reserved addresses, usable only for LAN addressing. These addresses range are :
10.*.*.*
172.16.*.* to 172.31.*.*
192.168.*.*
* means any value between 0 and 255. Note: To avoid some specials case which may generate trouble, do not use the numbers 0 and 255, so stay with 1 to 254 inclusive.
The last concept to know a bit about is the concept of subnetwork: a subnetwork is a set of computers which may communicate directly to each other, without passing thru special devices called routers.
For example, 192.168.10.* is a subnetwork which may be composed of up to 254 computers able to communicate directly; 192.168.33.* is another one, etc... (again * means a value between 1 and 254)
At your home, if you have more than one computer and you want them to be able to communicate with each other or share some common resources (some files for instances), then to ease the things, it is preferable they share the same subnetwork address. This is where the "network mask" comes (see
http://en.wikipedia.org/wiki/Subnetwork).Let's have a middle sized example, with 3 computers, and ADSL modem, an IP printer and the CS2:
1) I choose the subnetwork of my home LAN, for instance 192.168.23.*. Once I have chosen it, all LAN addresses must start with this value, and you may choose from 1 to 254 as the last number (number D) for the various computers connected to the LAN.
2) My own computer has address 192.168.23.5; the netmask is 255.255.255.0;
3) My son's computer has address 192.168.23.12; the netmask is 255.255.255.0;
4) My wife's computer has address 192.168.23.18; the netmask is 255.255.255.0;
5) the IP printer has address 192.168.23.100; the netmask is 255.255.255.0;
6) the ADSL modem has two addresses, one WAN (Wide Area Network = Internet) address given by my ADSL provider, for instance 200.200.100.12 and generally a special value for the mask (255.255.255.255), and a LAN address with the same subnetwork as 1), for instance 192.168.23.2 and the netmask 255.255.255.0
7) for the CS2 to be able to communicate with 2), the CS2 must have an unused address in the 192.168.23 subnetwork, let's say 192.168.23.40, and its network mask equals to 255.255.255.0 (the English translation in the CS2 for the network mask is called "IP Network template"). For the IP gateway of the CS2, either enter the modem LAN address or the address of the calling computer 2), and for the DNS address, enter the DNS address given by your Internet provider.
In summary:
-Choose a subnetwork address 192.168.C with "C" between 1 and 254, and stay with it
-Assign the final part of the IP address (D number) between 1 and 254. Please note that all computers must have a different "D" value.
-Use a network mask equals to 255.255.255.0
-Test the communication between your computer and the CS2 by issuing the command "ping <CS2_Address>" where <CS2_Address> is the value set at step 7 above.
Feel free to amend, add, correct if mistakes, provide better examples, etc...
Cheers
Fabrice
Edited by user 08 May 2014 22:36:50(UTC)
| Reason: Not specified