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🛡️ Network Security
Networking fundamentals and security practices
1. Network Commands
What is it? Network commands help you check connections, find IP addresses, and troubleshoot network issues.
network_commands.sh
# ifconfig - show network interfaces
ifconfig
# ip - show IP addresses
ip addr show
# ping - test connection
ping -c 4 google.com
# nslookup - find IP of website
nslookup google.com
# netstat - show open ports
netstat -tlnp
# wget - download file
wget https://example.com/file.zip
# curl - send web request
curl https://example.com
2. Firewall - Protect Your Computer
What is it? A firewall is like a security guard for your computer. It decides which data can come in and go out.
firewall_config.sh
# UFW - simple firewall
sudo ufw enable # Turn on firewall
sudo ufw disable # Turn off firewall
sudo ufw status # Check status
# Allow and deny ports
sudo ufw allow 22 # Allow SSH
sudo ufw deny 80 # Block HTTP
sudo ufw allow 443 # Allow HTTPS
# Delete a rule
sudo ufw delete allow 80