Finally, Alex had to open the "gates" of the router's firewall. Under , he added three critical entries to allow traffic through the router's Input chain: UDP Port 500 for IKE (Internet Key Exchange) UDP Port 4500 for IPsec NAT Traversal UDP Port 1701 for the L2TP traffic itself
Once configurations on both the router and client devices (such as Windows, macOS, iOS, or Android) are complete, you can monitor the status of connections. Monitoring Active Connections
In the window, fill in the following settings: mikrotik l2tp server setup full
/ip pool add name=l2tp-vpn-pool ranges=192.168.89.10-192.168.89.50 Use code with caution. 3. Step 2: Configure the PPP Profile
💡 If your clients are behind a NAT, ensure "NAT Traversal" is active in your IPsec settings to prevent connection drops. Finally, Alex had to open the "gates" of
/ip firewall filter add chain=forward src-address=192.168.100.0/24 dst-address=192.168.88.0/24 action=accept comment="VPN to LAN"
/ip firewall filter add chain=input protocol=udp dst-port=500,1701,4500 action=accept comment="L2TP/IPsec" /ip firewall filter add chain=input protocol=ipsec-esp action=accept comment="ESP" /ip firewall filter add chain=input protocol=gre action=accept comment="GRE" /ip firewall filter add chain=forward src-address=192.168.100.0/24 action=accept comment="VPN Forward" Open Command Prompt as Administrator and run: Do
Fix: You must modify the Windows Registry. Open Command Prompt as Administrator and run:
Do your VPN clients need (all internet traffic goes through VPN) or split tunnel (only local traffic goes through VPN)? Are either your router or clients behind a double NAT ? Share public link
With a final click of "Apply," the server was live. Alex tested it from his own laptop, entering the office's public IP and the pre-shared key. As the "Connected" status appeared on his screen, he knew the team could now collaborate securely from anywhere in the world.