SSL VPN and IPsec Dial-Up VPN Not Working

Question

We are currently using a Next-Generation Firewall 201G running on FortiOS 7.4.11. The firewall is connected to the ISP LAN port, and the ISP firewall has a DMZ configured towards our firewall, with all required ports forwarded to it.

We attempted to configure both SSL VPN and IPsec Dial-up VPN; however, neither of them is working. We have thoroughly verified the configuration, and all required policies are correctly in place. I have also followed the official Fortinet documentation step by step to troubleshoot the issue, but the problem still persists.

Administrative access via HTTPS is enabled on the WAN interface, and Dynamic DNS is correctly resolving to the ISP public IP address. However, the firewall is not accessible from the public internet. Since the firewall itself is not reachable externally, SSL VPN communication is also failing.

This situation is extremely frustrating. Even Fortinet support has not been helpful so far—they are repeatedly requesting logs, but no relevant logs are being generated for this issue.

We urgently need assistance to resolve this matter.

sbaikadi · Answer

Hello @BavaBahurudeen

You may have already tried some of the steps mentioned here, just in case you didnt..

Considering the connecitivity to the firewall from external

-if you are pinging to the firewall interface from external, are you able to see the packets incoming to the interface when you run a sniffer on it?

-does your ISP firewall receive the ICMP/HTTPS packets from you when you try to reach from external address?

-is there any restriction of IPs list to the firewall WAN IP and if so, is the IP that you are coming from is whitelisted?

Sign up

Login with SSO

Login to the community

Login with SSO