[2025] Setting Up StrongSwan IPSec VPN: A Comprehensive Guide #strongswan #ipsec #SonicWall

In this video, we'll walk you through the complete process of setting up a StrongSwan VPN server on Ubuntu and configuring it to work seamlessly with SonicWall. Whether you're a network administrator or an enthusiast looking to enhance your network security, this step-by-step guide will help you get started. https://drive.google.com/file/d/1WIfrBJJIKd_uZBlSf1V7cl02HyOdTT8U/view What You'll Learn: StrongSwan Installation: How to install StrongSwan and related packages on Ubuntu. IP Forwarding: Enabling IP forwarding to allow traffic from the VPN tunnel to the internet. NAT Configuration with iptables: Setting up NAT to translate private IP addresses of VPN clients to the public IP address of the server. StrongSwan Configuration: Configuring StrongSwan to handle both fixed IP and dynamic IP connections. Aggressive Mode with PSK: Modifying StrongSwan settings to enable Aggressive Mode with PSK (not recommended for security reasons). Restarting Services: Restarting the StrongSwan service to apply new configurations. Verification: Checking the status of IP forwarding and iptables rules to ensure everything is set up correctly. Troubleshooting Commands: Useful commands to troubleshoot and verify your StrongSwan setup. Commands and Settings: 1. StrongSwan Installation: sudo apt update sudo apt install strongswan strongswan-pki libcharon-extra-plugins libcharon-extauth-plugins libstrongswan-extra-plugins 2. IP Forwarding: Temporarily: sudo sysctl -w net.ipv4.ip_forward=1 Permanently: sudo nano /etc/sysctl.conf Add the following line: net.ipv4.ip_forward=1 Apply the changes: sudo sysctl -p 3. NAT Configuration with iptables: Install iptables: sudo apt install iptables Add NAT Rules: sudo iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE sudo iptables -A FORWARD -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT sudo iptables -A FORWARD -i eth0 -o eth0 -j ACCEPT Save iptables Rules: sudo apt-get install iptables-persistent sudo netfilter-persistent save sudo netfilter-persistent reload 4. StrongSwan Configuration: Edit ipsec.conf: sudo nano /etc/ipsec.conf Add the following configuration: config setup charondebug="ike 2, knl 2, cfg 2" nat_traversal=yes conn vpn-static keyexchange=ikev2 ike=aes256-sha256-modp2048! esp=aes256gcm16! dpdaction=clear dpddelay=300s rekey=no left=10.0.0.4 leftid=10.0.0.4 leftsubnet=10.0.0.0/24 right=208.263.110.51 rightid=208.263.110.51 rightsubnet=0.0.0.0/0 authby=secret lifetime=28800s auto=start leftfirewall=yes conn vpn-dynamic keyexchange=ikev1 ike=aes256-sha256-modp2048! esp=aes256gcm16! dpdaction=restart dpddelay=30s dpdtimeout=120s rekey=no left=10.0.0.4 leftid=10.0.0.4 leftsubnet=10.0.0.0/24 right=%any rightid=%any rightsubnet=0.0.0.0/0 authby=secret lifetime=28800s auto=start leftfirewall=yes aggressive = yes Edit ipsec.secrets: sudo nano /etc/ipsec.secrets Add the following line: 10.0.0.4 any: PSK S3rv3r#2024T3st#C@seH@ck3r$123 5. StrongSwan Configuration for Aggressive Mode with PSK: Edit strongswan.conf: sudo nano /etc/strongswan.conf Add the following configuration: charon { load_modular = yes plugins { include strongswan.d/charon/*.conf } i_dont_care_about_security_and_use_aggressive_mode_psk = yes } include strongswan.d/*.conf 6. Restart StrongSwan Service: sudo systemctl restart strongswan-starter.service 7. Verify Configuration: Check IP forwarding: sudo sysctl net.ipv4.ip_forward Check iptables rules: sudo iptables -t nat -L sudo iptables -L 8. Troubleshooting Commands: sudo ip xfrm policy sudo journalctl -u strongswan-starter sudo ipsec statusall sudo nano /etc/ipsec.conf sudo systemctl restart strongswan-starter.service sudo nano /etc/ipsec.secrets sudo nano /etc/strongswan.conf sudo ipsec verify ip route show table 220 By following these steps, you will have a fully functional StrongSwan VPN server integrated with SonicWall, ready to secure your network traffic. If you have any questions or need further assistance, feel free to leave a comment below! Don't forget to like, share, and subscribe for more tutorials on network security and VPN setups! #VPNSetup #NetworkSecurity #StrongSwan