Fortigate VPN Authnetication fails intermittently.
Do a sniffer to the NPS/Radius server from the FortiGate Firewall to find the error. If you find the below error. Then apply the solution below on the NPS Radius server. Windows server might refuse NTLM connections because NTLMv1 is disabled by default. Enable NTLMv1 in the server as follows: Start > Administrative Tools > … Read more