2025-02-06
Networking is the foundation of modern communication, essential for anyone in tech. Here’s a quick rundown:
1️⃣ IP Addresses & Subnetting: Your device’s “home address” on the internet.
– Use `ifconfig` or `ip addr` to view your IP address on Linux.
– For subnetting, calculate using tools like `ipcalc` or manually with binary conversion.
2️⃣ Protocols: Rules like HTTP, FTP, and TCP/IP enable communication.
– Test HTTP connectivity with `curl http://example.com`.
– Use `ftp` command for file transfers or `nc` (netcat) for TCP/UDP connections.
3️⃣ DNS: Translates domain names (e.g., google.com) into IP addresses.
– Use `dig google.com` or `nslookup google.com` to query DNS records.
– Edit `/etc/resolv.conf` to configure DNS servers.
4️⃣ Firewalls: Protect networks from unauthorized access.
- Use `ufw` (Uncomplicated Firewall) on Linux:
- Enable: `sudo ufw enable`
- Allow SSH: `sudo ufw allow ssh`
- Check status:
sudo ufw status verbose.
5️⃣ OSI Model: Explains how data travels across 7 layers.
– Use `tcpdump` to capture and analyze network traffic:
– Example: `sudo tcpdump -i eth0 -n` to monitor traffic on interface eth0.
What Undercode Say
Networking is the backbone of cybersecurity and IT infrastructure. Understanding its basics is crucial for securing systems and troubleshooting issues. Here are some advanced Linux commands and tools to deepen your knowledge:
- Network Scanning: Use `nmap` to scan for open ports and services:
- Example: `nmap -sS 192.168.1.1` for a SYN scan.
- Packet Analysis: Analyze packets with `Wireshark` or `tshark` in the terminal:
- Example: `tshark -i eth0 -f “tcp port 80″` to capture HTTP traffic.
Routing: View routing tables with `route -n` or
ip route show.Bandwidth Monitoring: Use `iftop` or `nload` to monitor real-time bandwidth usage.
VPN Setup: Configure OpenVPN for secure connections:
- Install: `sudo apt install openvpn`
Connect:
sudo openvpn --config client.ovpn.DNS Security: Use `dnscrypt-proxy` to encrypt DNS queries:
- Install: `sudo apt install dnscrypt-proxy`
Configure: Edit
/etc/dnscrypt-proxy/dnscrypt-proxy.toml.Firewall Logs: Monitor logs with `journalctl -u ufw` or
grep UFW /var/log/syslog.Network Troubleshooting: Use
ping,traceroute, and `mtr` to diagnose connectivity issues.SSH Hardening: Secure SSH by editing
/etc/ssh/sshd_config:- Disable root login: `PermitRootLogin no`
Use key-based authentication:
PasswordAuthentication no.Automation: Write scripts with `bash` to automate network tasks.
For further reading, explore:
Mastering these tools and commands will empower you to secure and optimize networks effectively. Networking is not just about connectivity; it’s about building a resilient and secure digital ecosystem.
References:
Hackers Feeds, Undercode AI
