2. Networking
∙ Computer networking refers to the process of
establishing connections between computers and
other devices to share information and resources. It
involves various technologies, protocols, and
methodologies that facilitate communication and
data exchange among connected devices
3. Types of Networks
∙ Local Area Network (LAN):
∙ The scope of a Local Area Network is limited to a small geographic area, such as a single
building, office, or campus. The purpose of a LAN is to facilitate communication and
resource sharing among devices within the same location. Examples of LAN include home
networks and office networks.
∙ Wide Area Network (WAN):
∙ The scope of a Wide Area Network spans a large geographic area, often connecting
LANs across cities, countries, or continents. The purpose of a WAN is to enable
communication and data exchange between distant locations. Examples of WAN include
the Internet and global corporate networks.
4. ∙ Metropolitan Area Network (MAN):
∙ Scope: This type of network covers a larger geographic area than a LAN but smaller
than a WAN, typically within a city. Purpose: The purpose of a MAN is to connect
multiple LANs within a metropolitan area. Examples: Some examples of MANs
include city-wide networks and university campuses.
∙ Personal Area Network (PAN):
∙ Scope: A PAN is a very small network, typically within the range of an individual
person. Purpose: The purpose of a PAN is to connect devices for personal use, such
as smartphones, tablets, and laptops. Examples: Bluetooth connections are a
common example of a PAN.
∙ Campus Area Network (CAN):
∙ Scope: A CAN is larger than a LAN but smaller than a MAN, typically covering a
university campus or corporate campus. Purpose: The purpose of a CAN is to
connect multiple buildings within a specific geographic area. Examples: Some
examples of CANs include university campus networks and corporate campus
networks.
5. ∙ Storage Area Network (SAN):
∙ A Storage Area Network (SAN) is a specialized network designed to provide high-
speed access to shared storage resources. Its purpose is to enable efficient and
centralized storage management for servers and data storage devices. SANs are
commonly used by enterprise storage networks.
∙ Home Area Network (HAN):
∙ A Home Area Network (HAN) is a network that connects devices within and around a
home. Its purpose is to facilitate communication and sharing of resources among
devices in a household. HANs are commonly used by smart home networks and home
automation systems.
∙ Virtual Private Network (VPN):
∙ A Virtual Private Network (VPN) utilizes public networks to create a secure, private
communication channel. Its purpose is to enable secure remote access to a private
network over the internet. VPNs are commonly used for remote work connections and
secure communication for businesses.
6. ∙ Intranet
∙ Intranet refers to a private network that operates within an organization. It is designed
to facilitate internal communication, collaboration, and sharing of resources.
Corporate intranets are some of the examples of this kind of network.
∙ Extranet
∙ Extranet, on the other hand, extends the capabilities of an intranet by enabling secure
communication and exchange of information with external partners, suppliers, or
customers. It is aimed at creating a platform for secure collaboration between an
organization and its external partners. Examples of extranet systems include supplier
portals and customer access systems.
7. Topologies
∙ Bus Topology:
∙ Description: In a bus topology, all devices share a single communication line. Data is transmitted
along the bus, and each device receives and processes the data intended for it.
∙ Advantages: Bus topology is simple and inexpensive to implement, making it suitable for small
networks.
∙ Disadvantages: Its performance can degrade as more devices are added, and a failure in the
bus can disrupt the entire network.
∙ Star Topology:
∙ Description: In a star topology, all devices are connected to a central hub or switch. Data passes
through the central point, and communication between devices occurs through the hub.
∙ Advantages: Star topology is easy to install and manage. If one connection fails, it doesn't affect
other devices.
∙ Disadvantages: If the central hub fails, the entire network is affected. Moreover, it requires more
cabling than bus topology.
8. ∙ Ring Topology:
∙ Description: In a ring topology, devices are connected in a circular fashion, forming a closed-
loop. Each device is connected to exactly two other devices, forming a ring.
∙ Advantages: It is simple and easy to install. Each device has equal access to the network.
∙ Disadvantages: Failure in one device or connection can disrupt the entire network. Adding or
removing devices can be challenging.
∙ Mesh Topology:
∙ Description: In a mesh topology, devices are interconnected, and each device may have a direct
connection to every other device in the network.
∙ Advantages: It has high redundancy and fault tolerance. There are multiple paths for data
transmission.
∙ Disadvantages: It is complex to set up and manage. It requires a significant amount of cabling.
9. ∙ Tree Topology:
∙ Description: A Tree Topology is a combination of the star and bus topologies. It is a
hierarchical arrangement of devices with multiple star-configured networks that are
connected to a central bus backbone.
∙ Advantages: The Tree Topology is scalable and allows for the expansion of the network. It
can be suitable for larger organizations.
∙ Disadvantages: The failure of the central bus can affect the entire network, and it can be
complex to manage.
∙ Hybrid Topology:
∙ Description: The Hybrid Topology is a combination of two or more different topologies. For
example, a network might combine elements of a star topology and a bus topology.
∙ Advantages: The Hybrid Topology offers the advantages of multiple topologies. It can be
customized to meet specific requirements.
∙ Disadvantages: The complexity can vary depending on the specific combination.
10. Routing And Switching
∙ Routing and switching are essential for computer networking and play critical roles in data
transmission and communication within a network.
∙ Routing:
∙ Routing refers to the process of moving data packets between different networks to ensure that they
reach their intended destination. This process is primarily handled by network devices known as
routers. Routers operate at the network layer (Layer 3 of the OSI model) and make decisions based on
logical addressing, such as IP addresses.
11. ∙ Switching:
∙ Switching is the process of transmitting data frames within a network, mainly in a
local area network (LAN). Switches, which are network devices operating at the data
link layer (Layer 2 of the OSI model), use MAC addresses to forward data frames to
the right destination within the same network.
12. IP address
∙ An IP (Internet Protocol) address is a sequence of numbers assigned to every device
connected to a computer network that uses the Internet Protocol for communication.
The primary role of an IP address is to identify the host or network interface and
provide the host's location in the network. IP addresses are vital in routing data
across the internet.
13. Types of IP
∙ IPv4: -
∙ Consists of a 32-bit address. - Written as four sets of decimal numbers separated by
periods (e.g., 192.168.1.1). - Provides approximately 4.3 billion unique addresses.
∙ IPv6: -
∙ Consists of a 128-bit address. - Written as eight groups of hexadecimal digits
separated by colons (e.g., 2001:0db8:85a3:0000:0000:8a2e:0370:7334). - Designed
to address the limitation of IPv4 and provide an immensely larger number of unique
addresses.
14. ∙ Public IP:
∙ Public IP Address is assigned by the Internet Service Provider (ISP) and used to
identify a device on the internet. It is visible to other devices on the internet.
∙ Private IP:
∙ Used within a private network, not directly accessible from the internet. Assigned by a
router or a DHCP server within the local network. Allows multiple devices to share a
single public IP address.
15. ∙ Static IP Address:
∙ Manually assigned to a device and does not change over time. Typically
used for servers, network devices, and other systems that need a consistent
address.
∙ Dynamic IP Address:
∙ Automatically assigned by a DHCP server when a device connects to the
network. Suitable for devices that don't require a fixed address.
16. Protocols
∙ In computer networking, protocols are a set of rules and conventions that determine
how data is transmitted and received over a network. These protocols establish the
format, timing, sequencing, and error-checking of data exchange between devices.
They guarantee that different devices and systems can communicate with each other
effectively
17. Common types of Protocols
∙ Transmission Control Protocol (TCP):
∙ TCP is a protocol that facilitates reliable and connection-oriented communication between
devices. It is frequently used for web browsing, email, and file transfers.
∙ Internet Protocol (IP):
∙ IP is a fundamental protocol that routes and addresses packets of data so that they can
travel across networks and reach their intended destination. There are two versions of IP:
IPv4, which uses 32-bit addresses, and IPv6, which uses 128-bit addresses.
18. ∙ Hypertext Transfer Protocol (HTTP):
∙ Description: HTTP is a protocol used for transmitting hypertext (text with hyperlinks) on the
World Wide Web.
∙ Use Cases: HTTP is primarily used for web browsing.
∙ Hypertext Transfer Protocol Secure (HTTPS):
∙ Description: HTTPS is a secure version of HTTP that encrypts data to ensure secure
communication over a computer network.
∙ Use Cases: HTTPS is used for secure web transactions such as online banking and e-
commerce
∙ File Transfer Protocol (FTP):
∙ Description: FTP is used for transferring files between a client and a server on a network.
∙ Use Cases: FTP is mainly used for uploading and downloading files.
∙ Simple Mail Transfer Protocol (SMTP):
∙ Description: SMTP is used for sending outgoing mail messages from a client to a server or
between servers.
∙ Use Cases: This protocol is used when sending emails.
19. ∙ Post Office Protocol (POP):
∙ Description: POP retrieves emails from a mail server to a client device, allowing users to receive
emails.
∙ Use Cases: POP is useful when you want to retrieve emails from a server to a single device.
∙ Internet Message Access Protocol (IMAP):
∙ Description: IMAP enables an email client to access emails stored on a mail server, making it
easier to manage emails across multiple devices.
∙ Use Cases: IMAP is helpful when you need to access emails from different devices.
∙ Domain Name System (DNS):
∙ Description: DNS resolves domain names to IP addresses. It translates human-readable
addresses into machine-readable ones, making it easier for computers to find the correct
website.
∙ Use Cases: DNS is useful when you need to translate domain names (e.g., www.example.com)
to IP addresses.
20. ∙ Dynamic Host Configuration Protocol (DHCP):
∙ Description: DHCP automatically assigns network configurations and IP addresses to devices
connected to a network.
∙ Use Cases: Simplifying IP address management within a network.
∙ Border Gateway Protocol (BGP):
∙ Description: BGP is a routing protocol that exchanges routing information between different
autonomous systems on the internet.
∙ Use Cases: BGP is used for internet routing.
∙ Secure Shell (SSH):
∙ Description: SSH is a secure protocol that provides remote access to a device over a network.
∙ Use Cases: SSH is utilized for secure command-line access and remote administration.
