Just to share my case: we already have a very strong VPN solution (2FA authentication and also AD integrated) to serve for limited number of users ( management team & IT team). In fact, setup for a new VPN user is quite complicated: we have to 1. Install VPN client software on user laptop, 2. install Google Authenticator on user phone, 3. Generate TOTP token, 4. Register the token into Google Authenticator respectively, 5. Train user how to use the VPN, 6. Some other supports.
Then we faced with the Covid-19 pandemic. In this situation, IT have to support for 170 users to work from home with time constrainst in this project is just 3 days ( including the installation/configuration at end user devices). The existing solution is not appropriate in the new situation. What is the new approach I used recently:
Vyos PPTP with Radius authentication
Windows 2K12 NPS as Radius server
Windows GPO + Powershell to auto-create VPN PPTP profile on all company laptops.
Just in 1day I did deliver the work from home solution to 170+ user. Connection is controlled by user account in AD. Management team are very happy with the prompt action from IT.
So men, please share with me your diagram then I may have comments to you. At my very early comment is probaly you haven’t yet routing between VPN subnet and your local subnets.
Good luck.