--- name: Network 101 description: This skill should be used when the user asks to "set up a web server", "configure HTTP or HTTPS", "perform SNMP enumeration", "configure SMB shares", "test network services", or needs guidance on configuring and testing network services for penetration testing labs. --- # Network 101 ## Purpose Configure and test common network services (HTTP, HTTPS, SNMP, SMB) for penetration testing lab environments. Enable hands-on practice with service enumeration, log analysis, and security testing against properly configured target systems. ## Inputs/Prerequisites - Windows Server or Linux system for hosting services - Kali Linux or similar for testing - Administrative access to target system - Basic networking knowledge (IP addressing, ports) - Firewall access for port configuration ## Outputs/Deliverables - Configured HTTP/HTTPS web server - SNMP service with accessible communities - SMB file shares with various permission levels - Captured logs for analysis - Documented enumeration results ## Core Workflow ### 1. Configure HTTP Server (Port 80) Set up a basic HTTP web server for testing: **Windows IIS Setup:** 1. Open IIS Manager (Internet Information Services) 2. Right-click Sites → Add Website 3. Configure site name and physical path 4. Bind to IP address and port 80 **Linux Apache Setup:** ```bash # Install Apache sudo apt update && sudo apt install apache2 # Start service sudo systemctl start apache2 sudo systemctl enable apache2 # Create test page echo "

Test Page

" | sudo tee /var/www/html/index.html # Verify service curl http://localhost ``` **Configure Firewall for HTTP:** ```bash # Linux (UFW) sudo ufw allow 80/tcp # Windows PowerShell New-NetFirewallRule -DisplayName "HTTP" -Direction Inbound -Protocol TCP -LocalPort 80 -Action Allow ``` ### 2. Configure HTTPS Server (Port 443) Set up secure HTTPS with SSL/TLS: **Generate Self-Signed Certificate:** ```bash # Linux - Generate certificate sudo openssl req -x509 -nodes -days 365 -newkey rsa:2048 \ -keyout /etc/ssl/private/apache-selfsigned.key \ -out /etc/ssl/certs/apache-selfsigned.crt # Enable SSL module sudo a2enmod ssl sudo systemctl restart apache2 ``` **Configure Apache for HTTPS:** ```bash # Edit SSL virtual host sudo nano /etc/apache2/sites-available/default-ssl.conf # Enable site sudo a2ensite default-ssl sudo systemctl reload apache2 ``` **Verify HTTPS Setup:** ```bash # Check port 443 is open nmap -p 443 192.168.1.1 # Test SSL connection openssl s_client -connect 192.168.1.1:443 # Check certificate curl -kv https://192.168.1.1 ``` ### 3. Configure SNMP Service (Port 161) Set up SNMP for enumeration practice: **Linux SNMP Setup:** ```bash # Install SNMP daemon sudo apt install snmpd snmp # Configure community strings sudo nano /etc/snmp/snmpd.conf # Add these lines: # rocommunity public # rwcommunity private # Restart service sudo systemctl restart snmpd ``` **Windows SNMP Setup:** 1. Open Server Manager → Add Features 2. Select SNMP Service 3. Configure community strings in Services → SNMP Service → Properties **SNMP Enumeration Commands:** ```bash # Basic SNMP walk snmpwalk -c public -v1 192.168.1.1 # Enumerate system info snmpwalk -c public -v1 192.168.1.1 1.3.6.1.2.1.1 # Get running processes snmpwalk -c public -v1 192.168.1.1 1.3.6.1.2.1.25.4.2.1.2 # SNMP check tool snmp-check 192.168.1.1 -c public # Brute force community strings onesixtyone -c /usr/share/seclists/Discovery/SNMP/common-snmp-community-strings.txt 192.168.1.1 ``` ### 4. Configure SMB Service (Port 445) Set up SMB file shares for enumeration: **Windows SMB Share:** 1. Create folder to share 2. Right-click → Properties → Sharing → Advanced Sharing 3. Enable sharing and set permissions 4. Configure NTFS permissions **Linux Samba Setup:** ```bash # Install Samba sudo apt install samba # Create share directory sudo mkdir -p /srv/samba/share sudo chmod 777 /srv/samba/share # Configure Samba sudo nano /etc/samba/smb.conf # Add share: # [public] # path = /srv/samba/share # browsable = yes # guest ok = yes # read only = no # Restart service sudo systemctl restart smbd ``` **SMB Enumeration Commands:** ```bash # List shares anonymously smbclient -L //192.168.1.1 -N # Connect to share smbclient //192.168.1.1/share -N # Enumerate with smbmap smbmap -H 192.168.1.1 # Full enumeration enum4linux -a 192.168.1.1 # Check for vulnerabilities nmap --script smb-vuln* 192.168.1.1 ``` ### 5. Analyze Service Logs Review logs for security analysis: **HTTP/HTTPS Logs:** ```bash # Apache access log sudo tail -f /var/log/apache2/access.log # Apache error log sudo tail -f /var/log/apache2/error.log # Windows IIS logs # Location: C:\inetpub\logs\LogFiles\W3SVC1\ ``` **Parse Log for Credentials:** ```bash # Search for POST requests grep "POST" /var/log/apache2/access.log # Extract user agents awk '{print $12}' /var/log/apache2/access.log | sort | uniq -c ``` ## Quick Reference ### Essential Ports | Service | Port | Protocol | |---------|------|----------| | HTTP | 80 | TCP | | HTTPS | 443 | TCP | | SNMP | 161 | UDP | | SMB | 445 | TCP | | NetBIOS | 137-139 | TCP/UDP | ### Service Verification Commands ```bash # Check HTTP curl -I http://target # Check HTTPS curl -kI https://target # Check SNMP snmpwalk -c public -v1 target # Check SMB smbclient -L //target -N ``` ### Common Enumeration Tools | Tool | Purpose | |------|---------| | nmap | Port scanning and scripts | | nikto | Web vulnerability scanning | | snmpwalk | SNMP enumeration | | enum4linux | SMB/NetBIOS enumeration | | smbclient | SMB connection | | gobuster | Directory brute forcing | ## Constraints - Self-signed certificates trigger browser warnings - SNMP v1/v2c communities transmit in cleartext - Anonymous SMB access is often disabled by default - Firewall rules must allow inbound connections - Lab environments should be isolated from production ## Examples ### Example 1: Complete HTTP Lab Setup ```bash # Install and configure sudo apt install apache2 sudo systemctl start apache2 # Create login page cat << 'EOF' | sudo tee /var/www/html/login.html EOF # Allow through firewall sudo ufw allow 80/tcp ``` ### Example 2: SNMP Testing Setup ```bash # Quick SNMP configuration sudo apt install snmpd echo "rocommunity public" | sudo tee -a /etc/snmp/snmpd.conf sudo systemctl restart snmpd # Test enumeration snmpwalk -c public -v1 localhost ``` ### Example 3: SMB Anonymous Access ```bash # Configure anonymous share sudo apt install samba sudo mkdir /srv/samba/anonymous sudo chmod 777 /srv/samba/anonymous # Test access smbclient //localhost/anonymous -N ``` ## Troubleshooting | Issue | Solution | |-------|----------| | Port not accessible | Check firewall rules (ufw, iptables, Windows Firewall) | | Service not starting | Check logs with `journalctl -u service-name` | | SNMP timeout | Verify UDP 161 is open, check community string | | SMB access denied | Verify share permissions and user credentials | | HTTPS certificate error | Accept self-signed cert or add to trusted store | | Cannot connect remotely | Bind service to 0.0.0.0 instead of localhost |