Command Line Tools (Network and System Troubleshooting)

These tools are typically used through the terminal or command prompt to test and diagnose network and system issues.

a. ping

• Purpose: Tests connectivity between two devices on a network.
• Usage:
  • ping [hostname/IP]
  • Example: ping 8.8.8.8 (pings Google’s public DNS server).
• When to use: If you want to check if a device or server is reachable on the network.

b. tracert (Traceroute on Windows) / traceroute (Linux/Mac)

• Purpose: Tracks the path data takes from one computer to another, showing all the hops between the source and destination.
• Usage:
  • Windows: tracert [hostname/IP]
  • Linux/Mac: traceroute [hostname/IP]
• When to use: To diagnose where data is getting delayed or blocked on the network.

c. ipconfig (Windows) / ifconfig (Linux/Mac)

• Purpose: Displays the network configuration of your computer, such as IP address, subnet mask, and default gateway.
• Usage:
  • Windows: ipconfig
  • Linux/Mac: ifconfig
• When to use: To check the network settings of your local machine.

d. nslookup

• Purpose: Queries DNS (Domain Name System) to obtain domain name or IP address mapping information.
• Usage: nslookup [hostname]
• When to use: To troubleshoot DNS-related issues and verify if a domain name resolves correctly.

e. netstat

• Purpose: Displays active network connections, routing tables, and interface statistics.
• Usage: netstat -a
• When to use: To view active connections or diagnose if a particular port is in use.

f. iperf

• Purpose: Measures the bandwidth and performance of your network.
• Usage: Requires two systems — one as a server and the other as a client to run the test.
  • Example: iperf -c [server IP] -t 10
• When to use: To test network speed between two devices or servers.

g. route

• Purpose: Displays or modifies the network routing table on your computer.
• Usage: route print (Windows), route -n (Linux/Mac)
• When to use: To troubleshoot routing issues, particularly if certain destinations are unreachable.