Networking for DevOps

What is Networking?

• Networking is the connection of computers or groups of devices connected to each other for sharing data and resources.
• Networking means Interconnection

Types of Networks

OSI Model

• International Standard Organization (ISO) established a committee in 1977 to develop an architecture for computer communication.
• Open system Interconnection (OSI) reference model is the result of the effort.
• In 1984 the open-system Interconnection (OSI) reference model was approved as an international standard for communication architecture.
• The term “open” denotes the ability to connect any two systems that confirm the reference model and associated standards.

There are 7 layers in OSI Model

1. Physical Layer

• The physical layer is the first layer of the OSI model
• In the physical layer all the physical connectivity of a network, such as the connectivity of devices using wire.
• Devices working under this layer are hubs, repeaters, cables, etc.
• The datagram at the Physical layer is called bits.

2. Datalink Layer

• Datalink is called the second layer of the OSI model.
• It provides the connection between hosts on the same network
• It converts bits into frames and forwards into the network layer.
• This layer is responsible for framing, physical addressing, flow control, error control, or access control.
• Devices that work in this layer are switch, bridge and NIC
• protocols under this layer are PPP, and PPTP.

3. Network Layar

• The network Layer is the third layer of the OSI model, It provides the connection between hosts on different networks.
• It Converts frames into packets and forwards them to the Transport layer.
• This layer is responsible for logical addressing, routing, etc.
• Devices under this layer are Routers and Brouters.
• Protocols used under this loyer are IPV4, IPV6, and ICMP.
• The datagram at the Network layer is called packet.

4. Transport layer:-

• The transport layer is the fourth layer of the OSI Model.
• It Converts packets into segments and forwards them to the Session layer.
• This layer is responsible for segmentation, connection Control, flow control, and error control.
• Protocols that work under this layer are: TCP and UDP
• Datagram at transport layer called segments.

5. Session Loyer:-

• The session layer is the fifth layer of Osi Moder
• It is responsible for dialog Control and synchronization
• This layer also controls duplexing, termination, and restart.
• Protocol works under this layer are TCP and RTP.

6. Presentation Layer

• The presentation layer is the sixth layer of Osi Madel.
• This layer is responsible for translation, encryption, and Compression.
• Protocols work under this layer is SSL.

7. Application Layer

• The application layer is the Loyer layer of the OSI Model.
• This is the only layer where the user can directly interact with the data.
• This layer Presides a user interface and supports Services such as mail access, File transfer, browning internet, and remote desktop.
• protocols work under this Loyer are FTP, TELNET, DHCP, DNS, POPS, SMTP

TCP/IP Model

• Transmission control/ Internet protocol suite
• Most popular in the history of network
• Support by every computer operating system
• TCP/IP is mentioned in an open forum.

There are four layers in TCP/IP

Application Layer:- Defines protocols for node-to-node application communication and also controls user-interface specifications.

Get Pradyumna Kumar Das’s stories in your inbox

Join Medium for free to get updates from this writer.

Remember me for faster sign in

Transport Layer:- Creates reliable and end-to-end communication and ensures the error-free delivery of data.

Internet Layer:- Takes care of the addressing of hosts by giving them an IP address and handles the routing of packets among multiple networks.

Network Access Layer:- Oversees hardware addressing and defines protocols for the physical transmission of data and monitors the data exchange between the hosts and the network.

IP Address

An IP (Internet Protocol)address is a unique address that identifies a device on the Internet or a local network.

• A unique identifier
• Way to identify machines on a network
• Used to connect to another computer
• Allow transfers of files and e-mail

IP Structure

• Consists of 32 bits, ex-11001000.00011010.00010101.11101001
• An IP address consists of four sections
• Each section has 8 bits.
• Each section ranges from 0 to 255.
• Four sections are known as octets.

Static IP Address: A static IP address is manually assigned to a computer/server by an administrator.

Dynamic IP Address:- Assigned by the computer interface or DHCP.

IP Addresses are of two types IPV4 and IPV6

1. IPv4 (Internet Protocol version 4): This is the most common type of IP address and is made up of four sets of numbers separated by periods (e.g., 192.168.1.1). Each set can have a value between 0 and 255. However, due to the limited number of possible combinations, IPv4 addresses have become increasingly scarce as more devices connect to the internet.
2. IPv6 (Internet Protocol version 6): As a response to the depletion of IPv4 addresses, IPv6 was developed. IPv6 addresses are much longer, consisting of eight groups of hexadecimal digits separated by colons (e.g., 2001:0db8:85a3:0000:0000:8a2e:0370:7334). IPv6 provides a vastly larger pool of addresses to accommodate the growing number of connected devices.

IPV4

• An IP address is written in decimal numbers.
• ex. 10.2.1.0, if I am converting it into binary it will be 00001010.000000010.00000001. 00000000
• IP address is divided into 4 octets, each octet has 8 bits.
• we are calculating 8bit as like below image

I am attaching 2 more handwritten notes for calculating of IP Address