Linux Network Commands Cheat Sheet with Examples Print

Introduction

This cheat sheet provides a comprehensive list of essential Linux network commands with examples. It is designed to help system administrators and network engineers efficiently manage and troubleshoot networks on various Linux distributions.

Basic Network Commands

1. Check Network Interfaces

List all network interfaces:

ip link show

2. Display Network Configuration

Show IP address and network details:

ip addr

3. Check Network Connectivity

Ping a remote server:

ping -c 4 example.com

4. Check Routing Table

View the system's routing table:

ip route

Advanced Network Commands

1. Test DNS Resolution

Use nslookup or dig for DNS resolution:

dig example.com

2. Monitor Network Traffic

Use iftop or nload to monitor traffic:

sudo iftop

3. Trace Network Route

Trace the path to a remote server:

traceroute example.com

4. Test Port Connectivity

Use telnet or nc to test port connectivity:

nc -zv example.com 80

Useful Network Tools

1. tcpdump

Capture network packets:

sudo tcpdump -i eth0

2. netstat

Display network connections:

netstat -tuln

3. ss

Show detailed socket statistics:

ss -tuln

4. curl and wget

Test HTTP/HTTPS connections:

curl -I http://example.com

Troubleshooting Tips

• Verify network interface status with ip link.
• Test DNS resolution using dig or nslookup.
• Check connectivity with ping and traceroute.
• Analyze network traffic using tcpdump.

Examples

1. Configure a Static IP

sudo ip addr add 192.168.1.100/24 dev eth0

2. Add a Default Gateway

sudo ip route add default via 192.168.1.1

3. Flush DNS Cache

Flush the DNS cache on Ubuntu:

sudo systemd-resolve --flush-caches

Conclusion

This cheat sheet provides an overview of essential Linux network commands. Regular use of these commands will help you master network management and troubleshooting on Linux systems.