TOTPRadius Network configuration

TOTPRadius – standard implementation diagram

The network diagram below is a recommended setup for a single TOTPRadius network (without VPN Web portal interface activated):

TOTPRadius Network configuration

As shown on the diagram, access to TOTPRadius appliance is limited to 3 other hosts only:

- RADIUS port from your VPN server to TOTPRadius appliance (UDP 1812)

- LDAP or LDAPs ports ( TCP 389/636 )from TOTPRadius to your Active Directory Domain controller

- Access to the TOTPRadius management interface ports (SSH, HTTP and HTTPS – tcp 22, 80 and 443) is recommended to be restricted to admin workstations only

TOTPRadius – VPN Web Portal implementation diagram

If you wish to implement FIDO2/Passwordless or Azure AD (Microsoft Entra ID) Oauth2/SSO VPN access for your users (available starting from v0.2.5), there is an additional configuration required in your network layout. The web portal is running as a separate web server on the same virtual appliance, instead of standard https port (443) used for admin interface, the VPN web portal responds on port 9443. This port cannot be used directly for technical reasons, so has to be NATted to port 443.

The network diagram in this case will look like shown below:

 TOTPRadius Network configuration

Below is the description of how such NATting can be configured using Meraki MX64 as an example.

Login to Meraki Cloud Dashboard, and navigate to your Network. Then, navigate to “Security & SD-WAN” and select Firewall

TOTPRadius Network configuration

Then, scroll down to 1:Many NAT section and add a NAT rule as shown on the example below

TOTPRadius Network configuration

Once this is configured, the VPN Web interface should be accessible from public Internet via https://public_IP/ URL (where public_IP is the one you specified in the 1:Many NAT rule). Leave "Allowed remote IPs" empty or "Any" if you plan to expose the appliance without using any CDN.   Please note that both FIDO2 and Oauth2 interfaces require an FQDN with a valid Web Certificate in order to function properly.

It is recommended to use the same FQDN for both the VPN portal and the Client VPN Host to eliminate the risk of DNS spoofing attacks
More information about VPN Portal security is available here.