Getting to know IP addressing and subnetting
For a computer to communicate within a computer network, it must have an IP address. As explained earlier, the IP address identifies the computer on that network. In addition, we encounter the term “subnet” in complex networks, which helps determine the specific network within the overall network. So far, the world of networks recognizes two IP-addressing technologies: Internet Protocol version 4 (IPv4) and Internet Protocol version 6 (IPv6). Nevertheless, even though IPv6-addressing technology is becoming increasingly plausible, it still prefers the role of spectator in the great arena of the internet, in which IPv4-addressing technology continues to be the norm.
First, let’s take a look at IPv4 network addresses.
IPv4 network addresses
A computer must have an IPv4 address assigned to its network interface to communicate. Therefore, an IPv4 addressing technology is often referred to as just an IP address in its most straightforward format. The v4 label represents the fourth version of IP addressing specified in the IETF publication, RCF 791. It is a logical element in a network that consists of 32 bits organized into four octets with 8 bits each, divided by a decimal point for simplicity of interpretation (for example, 192.168.1.1). Additionally, IETF’s RFC 791 document organizes IP addresses into 8-bit, 16-bit, or 24- bit prefixes. That introduces the classful addressing that enables IP addresses to be classified as A, B, C, D, and E. The classful addressing organizes the IPv4 addresses into the bits used for the network and the host portions for a given class. From what has been said about IPv4, if you think that internet traffic is realized mainly through IPv4 addresses, I will tell you that you are not wrong:
Table 1.1 – IPv4 classes and their corresponding ranges
Now, let’s look at the IPv6 addressing technology introduced to overcome the IPv4 address exhaustion of IPv4 network addresses.
IPv6 network addresses
Today, internet traffic is supposed to be IPv6 -driven, but it is not. However, at the time of writing, according to Google IPv6 statistics, 32.57% of internet traffic is managed by IPv6 addressing technology, which is not bad! Therefore, an IPv6 addressing technology is another logical element in identifying a device on a computer network. The label, v6, represents the sixth version of IP addressing, as specified in the IETF publication, RFC 2460. Unlike IPv4, IPv6 is a 128-bit address size of 8 hextets with 16 bits each, divided by a colon for simplicity of interpretation (for example, 2001:0DB8:85A3:0000:0000:8A2E:0370:7334). The fact that IPv6 uses 128 bits makes it possible to use 2,128 IPv6 addresses, which gives an approximate number of 340 undecillion IPv6 addresses. Undoubtedly, that represents a vast number of available IPv6 addresses.
Next, we look at IPv4 subnetting, which is vital in identifying the network addresses.
IPv4 subnetting
Subnetting represents a logical division of one extensive network into multiple smaller networks. A subnet mask plays an essential role in identifying the network and determining the size of the subnet. Additionally, subnetting enables you to specify a given network’s network address, host addresses, and broadcast address. A subnet mask is a 32-bit address combined with an IPv4 address to indicate a network and its hosts.
The default subnet masks, otherwise known as classful networks, for each class of IPv4 addresses are shown in Table 1.2:
Table 1.2 – The IPv4 classful networks
Important note
You can learn more about IPv4-addressing technology, address space exhaustion, and classful networks at https://blogs.igalia.com/dpino/2017/05/25/ipv4-exhaustion/.
So far, we have understood what a computer network is and the various types, components, and architectures available. The following section will introduce Windows Server and its related concepts.
