What Is the Network? A network is a group of two or more connected computing devices. Usually, all devices in the network are connected to a central hub — for instance, a router. A network can also include subnetworks or smaller subdivisions of the network. Subnetworking is how very large networks, such as those provided by ISPs, are able to manage thousands of IP addresses and connected devices. What Happens at the Network Layer? Anything that has to do with inter-network connections takes place at the network layer. This includes setting up the routes for data packets to take, checking to see if a server in another network is up and running, and addressing and receiving IP packets from other networks. This last process is perhaps the most important, as the vast majority of Internet traffic is sent over IP. What Is a Packet? All data sent over the Internet is broken down into smaller chunks called "packets." When Bob sends Alice a message, for instance, his message is broken down into smaller pieces and then reassembled on Alice's computer. A packet has two parts: the header, which contains information about the packet itself, and the body, which is the actual data being sent. At the network layer, networking software attaches a header to each packet when the packet is sent out over the Internet, and on the other end, networking software can use the header to understand how to handle the packet. A header contains information about the content, source, and destination of each packet (somewhat like stamping an envelope with a destination and return address). For example, an IP header contains the destination IP address of each packet, the total size of the packet, an indication of whether or not the packet has been fragmented (broken up into still smaller pieces) in transit, and a count of how many networks the packet has traveled through. What Is the (OSI) Model? (OSI) model is a conceptual framework that divides network communications functions into seven layers OSI Model Application


Data generated by and usable by software applications. The main protocol used at this layer is HTTP.



presentation


Data is translated into a form the application can accept. Some authorities consider HTTPS encryption and decryption to take place at this layer.



session


Controls connections between computers (this can also be handled at layer 4 by the TCP protocol).



Transport


Provides the means for transmitting data between the two connected parties, as well as controlling the quality of service. The main protocols used here are TCP and UDP.



Network


Handles the routing and sending of data between different networks. The most important protocols at this layer are IP and ICMP.



DataLink


Handles communications between devices on the same network. If layer 3 is like the address on a piece of mail, then layer 2 is like indicating the office number or apartment number at that address. Ethernet is the protocol most used here.



Physical

Packets are converted into electrical, radio, or optical pulses and transmitted as bits (the smallest possible units of information) over wires, radio waves, or cables. Layers Layer 1 Devices


Analog Modem


HUB



Layer 2 Devices


Switch


Wireless Access Point (Wap)



Layer 3 Devices

Multi-layer switch
Router Security Devices Firewall
intrusion detection system (IDS)
intrusion presentation system (IPS)
virtual private network (VPN) Optimization And Performance Devices In short, Network Optimization refers to the tools, techniques, and best practices used to monitor and improve network performance. It involves analyzing the network infrastructure, identifying bottlenecks and other performance issues, and implementing solutions to eliminate or mitigate them. Load balancer
Proxy server Networking Services And Application Network services are applications at the network application layer that connect users working in offices, branches, or remote locations to applications and data in a network. These services typically run on servers. VPN Types

site-to-site
host-to-site (remote access)
host-to-host (SSL) Protocol Used By Vpn Internet Protocol Security (IPsec)
Generic Routing Encapsulation (GRE)
Point-to-Point Tunneling Protocol (PPTP)
Transport Layer Security (TLS) Protocol
Secure Socket Layer (SSL) Protocol What Protocols Are Used at the Network Layer? A protocol is an agreed-upon way of formatting data so that two or more devices are able to communicate with and understand each other. A number of different protocols make connections, testing, routing, and encryption possible at the network layer, including: IP (Internet Protocol)
IPsec (Internet Protocol Security)
ICMP (Internet Control Message Protocol)
IGMP (Internet Group Management Protocol)
GRE (Generic Routing Encapsulation) Resources: https://www.cloudflare.com/learning/network-layer/what-is-the-network-layer/ Thanks for reading. Regards, Elliot :) What Is the Network? What Is the Network? A network is a group of two or more connected computing devices. Usually, all devices in the network are connected to a central hub — for instance, a router . A network can also include subnetworks or smaller subdivisions of the network. Subnetworking is how very large networks, such as those provided by ISPs, are able to manage thousands of IP addresses and connected devices. router subnetworks What Happens at the Network Layer? What Happens at the Network Layer? Anything that has to do with inter-network connections takes place at the network layer. This includes setting up the routes for data packets to take, checking to see if a server in another network is up and running, and addressing and receiving IP packets from other networks. This last process is perhaps the most important, as the vast majority of Internet traffic is sent over IP. What Is a Packet? What Is a Packet? All data sent over the Internet is broken down into smaller chunks called "packets." When Bob sends Alice a message, for instance, his message is broken down into smaller pieces and then reassembled on Alice's computer. A packet has two parts: the header, which contains information about the packet itself, and the body, which is the actual data being sent. At the network layer, networking software attaches a header to each packet when the packet is sent out over the Internet, and on the other end, networking software can use the header to understand how to handle the packet. A header contains information about the content, source, and destination of each packet (somewhat like stamping an envelope with a destination and return address). For example, an IP header contains the destination IP address of each packet, the total size of the packet, an indication of whether or not the packet has been fragmented (broken up into still smaller pieces) in transit, and a count of how many networks the packet has traveled through. IP address What Is the (OSI) Model? What Is the (OSI) Model? (OSI) model is a conceptual framework that divides network communications functions into seven layers OSI Model OSI Model Application


Data generated by and usable by software applications. The main protocol used at this layer is HTTP. presentation


Data is translated into a form the application can accept. Some authorities consider HTTPS encryption and decryption to take place at this layer. session


Controls connections between computers (this can also be handled at layer 4 by the TCP protocol). Transport


Provides the means for transmitting data between the two connected parties, as well as controlling the quality of service. The main protocols used here are TCP and UDP. Network


Handles the routing and sending of data between different networks. The most important protocols at this layer are IP and ICMP. DataLink


Handles communications between devices on the same network. If layer 3 is like the address on a piece of mail, then layer 2 is like indicating the office number or apartment number at that address. Ethernet is the protocol most used here. Physical

Packets are converted into electrical, radio, or optical pulses and transmitted as bits (the smallest possible units of information) over wires, radio waves, or cables. Application Data generated by and usable by software applications. The main protocol used at this layer is HTTP. Data generated by and usable by software applications. The main protocol used at this layer is HTTP. Data generated by and usable by software applications. The main protocol used at this layer is HTTP. Data generated by and usable by software applications. The main protocol used at this layer is HTTP . HTTP presentation Data is translated into a form the application can accept. Some authorities consider HTTPS encryption and decryption to take place at this layer. Data is translated into a form the application can accept. Some authorities consider HTTPS encryption and decryption to take place at this layer. Data is translated into a form the application can accept. Some authorities consider HTTPS encryption and decryption to take place at this layer. Data is translated into a form the application can accept. Some authorities consider HTTPS encryption and decryption to take place at this layer. HTTPS encryption session Controls connections between computers (this can also be handled at layer 4 by the TCP protocol). Controls connections between computers (this can also be handled at layer 4 by the TCP protocol). Controls connections between computers (this can also be handled at layer 4 by the TCP protocol). Controls connections between computers (this can also be handled at layer 4 by the TCP protocol ). TCP protocol Transport Provides the means for transmitting data between the two connected parties, as well as controlling the quality of service. The main protocols used here are TCP and UDP. Provides the means for transmitting data between the two connected parties, as well as controlling the quality of service. The main protocols used here are TCP and UDP. Provides the means for transmitting data between the two connected parties, as well as controlling the quality of service. The main protocols used here are TCP and UDP. Provides the means for transmitting data between the two connected parties, as well as controlling the quality of service. The main protocols used here are TCP and UDP . UDP Network Handles the routing and sending of data between different networks. The most important protocols at this layer are IP and ICMP. Handles the routing and sending of data between different networks. The most important protocols at this layer are IP and ICMP. Handles the routing and sending of data between different networks. The most important protocols at this layer are IP and ICMP. Handles the routing and sending of data between different networks. The most important protocols at this layer are IP and ICMP. DataLink Handles communications between devices on the same network. If layer 3 is like the address on a piece of mail, then layer 2 is like indicating the office number or apartment number at that address. Ethernet is the protocol most used here. Handles communications between devices on the same network. If layer 3 is like the address on a piece of mail, then layer 2 is like indicating the office number or apartment number at that address. Ethernet is the protocol most used here. Handles communications between devices on the same network. If layer 3 is like the address on a piece of mail, then layer 2 is like indicating the office number or apartment number at that address. Ethernet is the protocol most used here. Handles communications between devices on the same network. If layer 3 is like the address on a piece of mail, then layer 2 is like indicating the office number or apartment number at that address. Ethernet is the protocol most used here. Physical Packets are converted into electrical, radio, or optical pulses and transmitted as bits (the smallest possible units of information) over wires, radio waves, or cables. Packets are converted into electrical, radio, or optical pulses and transmitted as bits (the smallest possible units of information) over wires, radio waves, or cables. Packets are converted into electrical, radio, or optical pulses and transmitted as bits (the smallest possible units of information) over wires, radio waves, or cables. Layers Layers Layer 1 Devices


Analog Modem


HUB Layer 2 Devices


Switch


Wireless Access Point (Wap) Layer 3 Devices

Multi-layer switch
Router Layer 1 Devices Analog Modem


HUB Analog Modem HUB Analog Modem Analog Modem HUB HUB Layer 2 Devices Switch


Wireless Access Point (Wap) Switch Wireless Access Point (Wap) Switch Switch Wireless Access Point (Wap) Wireless Access Point (Wap) Layer 3 Devices Multi-layer switch
Router Multi-layer switch Router Multi-layer switch Router Security Devices Security Devices Firewall intrusion detection system (IDS) intrusion presentation system (IPS) virtual private network (VPN) Firewall intrusion detection system (IDS) intrusion presentation system (IPS) virtual private network (VPN) Optimization And Performance Devices Optimization And Performance Devices In short, Network Optimization refers to the tools, techniques, and best practices used to monitor and improve network performance. It involves analyzing the network infrastructure, identifying bottlenecks and other performance issues, and implementing solutions to eliminate or mitigate them. Load balancer Proxy server Load balancer Proxy server Networking Services And Application Networking Services And Application Network services are applications at the network application layer that connect users working in offices, branches, or remote locations to applications and data in a network . These services typically run on servers. applications at the network application layer that connect users working in offices, branches, or remote locations to applications and data in a network VPN Types

site-to-site
host-to-site (remote access)
host-to-host (SSL) VPN Types site-to-site
host-to-site (remote access)
host-to-host (SSL) site-to-site host-to-site (remote access) host-to-host (SSL) site-to-site host-to-site (remote access) host-to-host (SSL) Protocol Used By Vpn Protocol Used By Vpn Internet Protocol Security (IPsec) Generic Routing Encapsulation (GRE) Point-to-Point Tunneling Protocol (PPTP) Transport Layer Security (TLS) Protocol Secure Socket Layer (SSL) Protocol Internet Protocol Security (IPsec) Generic Routing Encapsulation (GRE) Point-to-Point Tunneling Protocol (PPTP) Transport Layer Security (TLS) Protocol Secure Socket Layer (SSL) Protocol What Protocols Are Used at the Network Layer? What Protocols Are Used at the Network Layer? A protocol is an agreed-upon way of formatting data so that two or more devices are able to communicate with and understand each other. A number of different protocols make connections, testing, routing, and encryption possible at the network layer, including: IP (Internet Protocol) IPsec (Internet Protocol Security) ICMP (Internet Control Message Protocol) IGMP (Internet Group Management Protocol) GRE (Generic Routing Encapsulation) IP (Internet Protocol) IPsec (Internet Protocol Security) ICMP (Internet Control Message Protocol) IGMP (Internet Group Management Protocol) GRE (Generic Routing Encapsulation) Resources: https://www.cloudflare.com/learning/network-layer/what-is-the-network-layer/ https://www.cloudflare.com/learning/network-layer/what-is-the-network-layer/ Thanks for reading. Regards, Elliot :)

Network++ Part 2

Read My Stories

Too Long; Didn't Read

Make resilience your competitive advantage

Network++ Part 1: A Beginner's Guide

About Author

Comments

TOPICS

THIS ARTICLE WAS FEATURED IN

Related Stories

Untitled Story

Network++ Part 2

Rules of Thumb for Software Engineering

The Noonification: How to Implement a Merkle Tree in Solidity (11/19/2023)

10x engineers take long naps

The Noonification: Perfect Duty Engineer (11/10/2022)

Network++ Part 2

Rules of Thumb for Software Engineering

The Noonification: How to Implement a Merkle Tree in Solidity (11/19/2023)

10x engineers take long naps

The Noonification: Perfect Duty Engineer (11/10/2022)

Light-Mode

Classic

Newspaper

Dark-Mode

Neon Noir

Minty

HN StartUps