📖 Linux Networking Basics

Networking is a core part of managing any Linux system. Whether you're debugging a server, configuring firewalls, or verifying communication between machines, Linux provides powerful built-in tools that give you deep visibility into your network state.

🌐 Why Networking Tools Matter

Linux networking utilities help you:

• Inspect network interfaces

• Verify connectivity

• Check routing

• Identify open ports and socket usage

• Troubleshoot application/service communication

These tools are essential for admins, DevOps engineers, and security professionals.

🔍 1. Inspecting Network Interfaces with ip

The ip command replaces legacy tools like ifconfig.

What it shows:

• All network interfaces

• Assigned IP addresses

• Interface status (UP/DOWN)

Use this command whenever you need to quickly check which IP your server or VM is using.

📡 2. Testing Connectivity with ping

Purpose:

• Sends ICMP echo packets

• Confirms if a host is reachable

• Helps measure latency

💡 Press Ctrl + C to stop continuous ping.

🔗 3. Viewing Connections with netstat

Although older, netstat is still widely used.

Options:

• -t → TCP

• -u → UDP

• -l → Listening ports

• -n → Numeric output (IP and port numbers)

Use this to quickly check which services are listening on which ports.

⚡ 4. Modern Alternative: ss

ss is a faster and more feature-rich replacement for netstat.

What it provides:

• Socket statistics

• Faster output

• More detailed connection information

For open ports:

🧠 Pro Tips for Networking in Linux

• Use ip r to view the routing table

• Prefer ss over netstat for performance

• Use ping -c 4 <host> to send a fixed number of packets

• Use ip link to view interface status

🚀 What’s Next?

Tomorrow’s post will cover:

Linux User Management

Creating users, managing groups, and understanding permissions with:
useradd, usermod, passwd, groupadd.

Stay tuned!