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Cover image for Linux Learning Journey – Day 16: Essential Networking Commands for Troubleshooting & Connectivity πŸŒπŸ› οΈ
Avinash wagh
Avinash wagh

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Linux Learning Journey – Day 16: Essential Networking Commands for Troubleshooting & Connectivity πŸŒπŸ› οΈ

After covering secure file transfers with SCP and rsync, Day 16 of my Linux learning journey focused on a core skill every Linux, Cloud, and DevOps engineer must master:

πŸ‘‰ Linux networking fundamentals and troubleshooting tools

In real-world environmentsβ€”whether on on-prem servers, cloud VMs, or Kubernetes nodesβ€”network issues are inevitable. Applications may fail to connect, services may time out, or servers may become unreachable. Knowing how to quickly diagnose these problems from the command line is critical.

πŸ”Ή What I Learned & Practiced

Today, I explored essential Linux networking commands that help verify connectivity, analyze routes, inspect interfaces, and debug network-level issues.

πŸ”Ή ping – Check Network Reachability

The first step in any network troubleshooting process is checking connectivity.

Example:

- ping google.com

βœ”οΈ What it does:

  • Sends ICMP echo requests
  • Confirms whether a host is reachable
  • Measures latency and packet loss

Use case:
Quickly verify internet access or server availability.

πŸ”Ή traceroute / tracepath – Track the Network Path

These tools show the path packets take to reach a destination.

Examples:

- traceroute google.com
- tracepath google.com

βœ”οΈ Key learnings:

  • Helps identify where network delays or failures occur
  • tracepath works without root privileges
  • Useful for diagnosing routing issues in cloud networks

πŸ”Ή mtr – Real-Time Network Diagnostics

mtr combines the functionality of ping + traceroute.

Example:

- mtr google.com

βœ”οΈ Why it’s powerful:

  • Shows real-time packet loss and latency
  • Helps detect unstable hops
  • Widely used in production troubleshooting

πŸ”Ή netstat – View Network Connections (Legacy but Useful)

Although being replaced by ss, netstat is still commonly encountered.

Example:

- netstat -tulnp

βœ”οΈ What it shows:

  • Listening ports
  • Active connections
  • Services using specific ports

Use case:
Check which service is using a port (e.g., 80, 443, 3306).

πŸ”Ή ip & ifconfig – Network Interface Details

Modern Linux uses the ip command, while ifconfig is older but still seen.

Examples:

- ip addr
- ip route
- ifconfig

βœ”οΈ Key learnings:

  • View IP addresses and network interfaces
  • Check routing tables
  • Diagnose misconfigured interfaces

πŸ”Ή hostname – System Identity

Example:

- hostname
- hostname -I

βœ”οΈ Use case:

  • Identify the system’s hostname
  • Verify IP addresses assigned to the machine

πŸ”Ή nslookup – DNS Resolution Testing

DNS issues can break applications even when servers are reachable.

Example:

- nslookup google.com

βœ”οΈ What it helps with:

  • Verify domain-to-IP resolution
  • Debug DNS-related issues
  • Essential for cloud and microservices setups

πŸ”Ή nslookup – DNS Resolution Testing

DNS issues can break applications even when servers are reachable.

Example:

- nslookup google.com

βœ”οΈ What it helps with:

  • Verify domain-to-IP resolution
  • Debug DNS-related issues
  • Essential for cloud and microservices setups

πŸ”Ή telnet – Test Port Connectivity

Although not secure for production use, telnet is excellent for testing.

Example:

- telnet google.com 80

βœ”οΈ Use case:

  • Check if a port is open and reachable
  • Quickly verify service availability

πŸ”Ή iwconfig – Wireless Network Information

Example:

- iwconfig

βœ”οΈ What it shows:

  • Wireless interface details
  • Signal strength and mode
  • Useful on laptops and wireless servers

πŸ”Ή Why Networking Skills Matter in Real Environments

These tools are essential because:

  • Cloud infrastructure relies heavily on networking
  • Microservices communicate over the network
  • Load balancers, firewalls, and security groups affect connectivity
  • Most production outages are network-related
  • Faster diagnosis = less downtime

πŸš€ Day 16 Takeaway

Day 16 helped me build confidence in network troubleshooting using Linux CLI tools.

I now have hands-on clarity on:

  • Verifying connectivity and latency
  • Tracing network paths and failures
  • Inspecting interfaces and routes
  • Diagnosing DNS and port-level issues
  • Understanding how Linux systems communicate in real-world setups

Networking may seem invisibleβ€”but when it breaks, everything stops.

Linux is becoming more practical, operational, and production-ready with every day of learning.

Consistency is still the real superpower πŸ”‘πŸ’ͺ

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