Skip to main content

Network Layer

Network Layer(Layer 3): It is responsible for the source-to-destination delivery of packets across multiple links(networks).It is also responsible for structuring and managing a multi-node network, including addressing, routing, and traffic control.

Functions include:


  • Logical Addressing: IP addressing is defined at the Network Layer of the OSI model. This layer adds a header to the packet coming from the upper layer that, among other things, indicates the logical addresses of the sender and receiver. IP addressing is also known as logical addressing.
  • Routing: When independent networks are connected together to create a large network, the connecting devices(routers/gateways) route the packets to their final destination. The decision which route/path should be followed to reach from source to destination is handled by the network layer. 

Comments

Popular posts from this blog

Configuring 2 backend servers and a load balancer with HAProxy

A load balancer is a device that distributes the traffic across a cluster of servers. In computing, load balancing improves the distribution of workloads across multiple computing resources, such as computers, a computer cluster, network links, central processing units, or disk drives.As a result, it improves responsiveness and increases the availability of applications.  For load balancing, we need to install LAMP server on backend servers and HAProxy on the load balancer. HAProxy is a free, open source software that provides a high availability load balancer and proxy server for TCP and HTTP based applications that spread requests across multiple servers. Here we will make two backend servers and one load balancer. At two backend servers enter the following commands— $sudo apt-get install apache2 $sudo apt-get install mysql-server $sudo apt-get install php libapache2-mod-php php-mysql $sudo gedit /var/www/html/index.html (Make some changes in t

Devices used in each layer of OSI Model

Pic: Wikipedia 1.Physical Layer- Bits: Hubs, Repeaters, Fibers, Cables, Microwave, Radio, etc. 2.Data Link Layer- Frames: Bridges, 2-Layer Switches, Ethernet, WiFi AP's 3.Network Layer- Packets: Routers, 3-Layer Switches. 4.Transport Layer- Segments: Load Balancers/Firewalls. 5.Session Layer- Data:  Load Balancers/Firewalls/Computers. 6.Presentation Layer- Data: Load Balancers/Firewalls/Computers. 7.Application Layer- Data:  Load Balancers/Firewalls/Computers.

Network Connection verification and Troubleshooting commands in Windows

To ensure the proper network connection in the system, we do the following three types of checking: ---   Check the NIC card --- Check whether we have an IP or not or our gateway is active or not by a ping test -----  Check if the port no or the service is active or not To check the connection go to command prompt and enter the commands >ping localhost  then NIC  working. >ping 172.29.0.1 then gateway working >ipconfig In computing, ipconfig (internet protocol configuration) is a console application (command line tool) in Microsoft Windows used to control the network connections on windows.It displays all current TCP/IP network configuration values and can modify DHCP and DNS settings. Usually, ipconfig command is used with the command-line switch  /all. > ipconfig /all This command shows the various network configurations, MAC address, default gateway and IP addresses of different servers on the network like dns, DHCP etc