I have users login into FortiGate VPN with Azure MFA authentication, the configuration is done using NPS component and it was working fine for couple of weeks today suddenly the users were facing latency of 1 - 2 mins in receiving MFA push and call notification on MS authenticator app, also they receive multiple notification challenges in MS authenticator app by accepting the challenge user is able to login inside.
Ping response between fortigate VPN and Azure NPS server is efficient.
When checked in Event viewer got below message:
User:
Security ID: NULL SID
Account Name: -
Account Domain: -
Fully Qualified Account Name: -
Client Machine:
Security ID: NULL SID
Account Name: -
Fully Qualified Account Name: -
OS-Version: -
Called Station Identifier: -
Calling Station Identifier: -
NAS:
NAS IPv4 Address: -
NAS IPv6 Address: -
NAS Identifier: -
NAS Port-Type: Virtual
NAS Port: -
RADIUS Client:
Client Friendly Name: RD Gateway
Client IP Address: xxx.xxx.xxx.xxx
Authentication Details:
Connection Request Policy Name: Use Windows authentication for all users
Network Policy Name: -
Authentication Provider: -
Authentication Server: xxxx.xx.xxxxx.com
Authentication Type: -
EAP Type: -
Account Session Identifier: 00000001
Reason Code: 10
Reason: The request was discarded because an extension dll crashed or malfunctioned.
Request to resolve this issue or provide steps to troubleshoot for the same.