A network is defined as a group of two or more than computer interconnected to each other and share its information as well as their resources. A telecommunications network, which allows computers to exchange data and information is a called a data network or computer network.

Troubleshooting is a systematic approach to problem-solving that is often used to find and correct issues with complex machines, electronics, computers and software systems. When something breaks on the Internet, the Internet's very decentralised structure makes it hard to figure out what went wrong and even harder to assign responsibility.

Network troubleshooting is the process to identify, diagnose, resolve or rectify the problems and issues within a computer network. These network troubleshooting problems are solved by network engineers. It is used to maintain, repair or optimize a network and also recover & establish a network or Internet connections on end devices.

Some of the processes within network troubleshooting include, but are not limited to:

• Finding and resolving problems and establishing Internet/network connection of a computer/device/node
• Configuring a router, switch or any network management device
• Installing cables or Wi-Fi devices
• Updating firmware devices on router switch
• Removing viruses
• Adding, configuring and reinstalling a network printer

Components in Network Troubleshooting

• It defines the model of extrinsic observations and intrinsic faulty problems as well as the relationship between them.
• It is monitoring and collect the observations.
• It diagnosis or to identify the faulty location and find out the root cause.

This blog contains the top basic tools that can help you troubleshoot most networking issues:-

• Route
• Pathping/meter
• Speedtest.net/pingtest.net
• Subnet and IP Calculator
• Putty/Tera Term
• Netstat
• Nslookup
• Ipconfig/ifconfig
• Tracert/traceroute
• Ping

Ping:- Ping is the most commonly used for network tools. It is a computer network administration software utility used to test the reachability of a host on an Internet Protocol. Ping is measure the time for a packet to travel to a remote host and back. The server sends back an acknowledgement when the packet arrives. Windows comes with a Ping client. It is a command line interface and It is run from a DOS command line window, not a graphical user interface. It is a query of computers on a network to determine whether there is a connection to it. In simple words, we can say that if the requesting host receives a response from the destination host, this host is reachable.
For example, if an Internet connection is down at an office, the ping utility can be used to figure out whether the problem exists within the office or within the network of the Internet provider. It shows an example of the ping utility being used to obtain the reachability status of the locally connected router.

Tracert/traceroute:- Mostly, once the ping utility has been used to determine basic connectivity. The Traceroute utility is one of the most commonly used diagnostic tools available to any network operator. It lists the router hops between the client host and a remote host. The IP address and domain name (if there is one) of each router are returned to the client. It allows you to examine the path a packet takes across the Internet, showing you each of the individual routers that handle the packet, as well as measuring the time (network latency). It takes to deliver the packet to each router. It shows an example of the tracer utility being used to find the path from a host inside an office at www.google.com. The tracer utility and traceroute utilities perform the same function, but operate on different operating systems.

• Tracert for Windows machines and
• Traceroute for Linux/*nix based machines.

Ipconfig/Ifconfig:- The Ipconfig utility command is used on Windows machines. It displays all current TCP/IP network configuration values and can modify a Dynamic Host Configuration Protocol DHCP and Domain Name System DNS settings. Whereas, The Ifconfig command is used on Linux, Mac OS X, and other Unix-like operating systems based machines. It is used to configure, control, and query TCP/IP network interface parameters from a command line interface (CLI) or in system configuration scripts.
These commands allow you to configure your network interfaces and view information about them.Once you must be checked or completed when troubleshooting a networking issue is to find out the specific IP configuration of the various affected hosts. Sometimes this information is already known when addressing is configured statically. But sometimes when a dynamic addressing method is used, the IP address of each host can potentially change often.
For Example:- It shows an example of the Ifconfig utility showing the IP configuration information of a query host.

Nslookup:- The Nslookup command is a powerful tool for diagnosing DNS problems. Moreover, most common networking issues related to the Dynamic Name System (DNS) address resolution issues. DNS is used by everyone using the Internet to resolve the problems commonly known domain names (i.e. google.com) to commonly unknown IP addresses (i.e. 74.125.115.147). Your computer is constantly querying its DNS servers to translate domain names to IP addresses. This command just allows you to do it manually.When this system does not work, most of the functionality that people are used to goes away, as there is no way to resolve this information.

Netstat:- Netstat stands for Network Statistics. This command displays incoming and outgoing network connections as well as other network information. It’s available on Windows, Mac, and Linux — each version has its own command-line options you can tweak to see different types of information. The Netstat utility can show you the open connections on your computer, which programs are making which connections, how much data is being transmitted, and other information.

Putty/Tera Term:- Putty is a free and open client server program for the SSH (Secure Shell). Putty does support encryption, so you should probably grab a copy if you intend to access a web server or protected resource with it. When connecting to a variety of different types of equipment, a telnet, SSH or serial client is required; when this is required both the puTTY and Tera Term programs are able to provide these functionalities. The selection of one over the other is strictly a personal preference. It below shows both puTTY and Tera Term being used to connect to a host via SSH.

Subnet and IP Calculator:- This is a more straightforward and faster IP subnet calculator, giving you a complete list of information concerning an IP address and Subnet Mask, including the Network and Host address size. While this type of tool is used by senior level network engineers, much of the information obtained from the tool becomes simpler to calculate the longer and more experience you have in the field. Two of the more commonly used free IP calculators include Wildpackets (Bitcricket) Network Calculator and Solarwinds Advanced Subnet Calculator which can be found at the links below.

http://www.bitcricket.com/downloads/IPCalculator.msi

http://downloads.solarwinds.com/solarwinds/Release/FreeTool/SolarWinds-Subnet-Calculator.zip

Pathping/mtr:- It is a a Windows based command-line tool and network utility supplied in Windows NT and beyond that combines the functionality of ping with that of tracert. It is used to provide information about the path data takes to its intended destination, network latency and network loss at intermediate hops between a source and destination. It provides details of the path between two hosts and Ping-like statistics for each node in the path based on samples taken over a time period, depending on how many nodes are between the start and end host.

• Finds intermediate routers
• Calculates statistics

Route:- It is a way or course taken in getting from a starting point to a destination. It is used to send or direct along a specified course.It is used to display the current status of the routing table on a host. While the use of the route utility is limited in common situations where the host only has a single IP address with a single gateway.