Duo Two-Factor Authentication for NetMotion Mobility

Overview

Duo two-factor authentication for NetMotion supports using the EAP (PEAP-GTC) mechanism against a RADIUS server using Duo's Authentication Proxy radius_client primary authentication or against an Active Directory domain controller using ad_client primary authentication. If you are not using Active Directory and do not have a RADIUS server that supports EAP you must deploy one (for example, Microsoft Network Policy Server or FreeRADIUS) before using Duo authentication. If using RADIUS as the primary authenticator with NetMotion EAP, the RADIUS server must permit use of PAP encryption.

You will need a certificate and corresponding key file when configuring the Duo Authentication Proxy. The key file must not be encrypted nor can it require a password for use. The certificate can be issued by a trusted certificate authority (CA) or self-signed. If you'd like to use a self-signed certificate, you can create one using OpenSSL following the example instructions here. If you have enabled the "Validate server certificate" option on your NetMotion Mobility clients, then you must use a certificate issued by a CA that your Mobility client systems trust.

This configuration doesn't support inline self-service enrollment. You'll need to create your users in Duo ahead of time using one of our other enrollment methods, like directory sync or CSV import. Read the enrollment documentation to learn more.

First Steps

Before moving on to the deployment steps, it's a good idea to familiarize yourself with Duo administration concepts and features like options for applications, and Duo policy settings and how to apply them. You'll need to pre-enroll your users in Duo using one of our available methods before they can log in using this configuration. See all Duo Administrator documentation.

You should already have a working primary authentication configuration for your NetMotion VPN users before you begin to deploy Duo.

To integrate Duo with your NetMotion VPN, you will need to install a local Duo proxy service on a machine within your network. This Duo proxy server will receive incoming RADIUS requests from your NetMotion VPN, contact your existing local LDAP/AD or RADIUS server to perform primary authentication if necessary, and then contact Duo's cloud service for secondary authentication.

If you are already running a Duo Authentication Proxy server in your environment, you can use that existing host for additional applications, appending the new configuration sections to the current config. You don't have to set up a new Authentication Proxy server for each application you create. However, there are some cases where it might make sense for you to deploy a new proxy server for a new application, like if you want to co-locate the Duo proxy with the application it will protect in the same data center.

We recommend the following 64-bit operating systems for the system hosting the Duo Authentication Proxy:

• Windows Server 2016 or later
• CentOS Stream 9 or later
• Fedora 39 or later
• Red Hat Enterprise Linux 7 or later
• Rocky Linux 9 or later
• Ubuntu 20.04 LTS or later
• Debian 11 or later

The Duo End of Sale, Last Date of Support, and End of Life Policy states that Duo does not offer support for integrations running on operating system versions beyond the vendor’s stated Last Date of Support date.

See detailed Authentication Proxy operating system performance recommendations in the Duo Authentication Proxy Reference.

We do not recommend installing the Duo Authentication Proxy on the same Windows server that acts as your Active Directory domain controller or one with the Network Policy Server (NPS) role. If you must co-locate the Duo Authentication Proxy with these services, be prepared to resolve potential LDAP or RADIUS port conflicts between the Duo service and your pre-existing services.

Then you'll need to:

1. Sign up for a Duo account.
2. Log in to the Duo Admin Panel and navigate to Applications → Protect an Application.
3. Locate the entry for NetMotion Mobility with a protection type of "2FA" in the applications list. Click Protect to get your integration key, secret key, and API hostname. You'll need this information to complete your setup. See Protecting Applications for more information about protecting applications in Duo and additional application options.

Install the Duo Authentication Proxy

If you will reuse an existing Duo Authentication Proxy server for this new application, you can skip the install steps and go to Configure the Proxy.

The Duo Authentication Proxy can be installed on a physical or virtual host. We recommend a system with at least 1 CPU, 200 MB disk space, and 4 GB RAM (although 1 GB RAM is usually sufficient). See additional Authentication Proxy performance recommendations in the Duo Authentication Proxy Reference.

We do not recommend installing the Duo Authentication Proxy on the same Windows server that acts as your Active Directory domain controller or one with the Network Policy Server (NPS) role. If you must co-locate the Duo Authentication Proxy with these services, be prepared to resolve potential LDAP or RADIUS port conflicts between the Duo service and your pre-existing services.

duoauthproxy-version.exe /S

duoauthproxy-version.exe /S /exclude-auth-proxy-manager

sudo ./duoauthproxy-build/install --install-dir /opt/duoauthproxy --service-user duo_authproxy_svc --log-group duo_authproxy_grp --create-init-script yes

Configure the Proxy

After the installation completes, you will need to configure the proxy.

The Duo Authentication Proxy configuration file is named authproxy.cfg, and is located in the conf subdirectory of the proxy installation. With default installation paths, the proxy configuration file will be located at:

Note that as of v4.0.0, the default file access on Windows for the conf directory is restricted to the built-in Administrators group during installation.

The configuration file is formatted as a simple INI file. Section headings appear as:

[section]

Individual properties beneath a section appear as:

name=value

The Authentication Proxy may include an existing authproxy.cfg with some example content. For the purposes of these instructions, however, you should delete the existing content and start with a blank text file.

Duo Authentication Proxy Manager

The Duo Authentication Proxy Manager is a Windows utility for managing the Authentication Proxy installation on the Windows server where you install the Authentication Proxy. The Proxy Manager comes with Duo Authentication Proxy for Windows version 5.6.0 and later.

The Proxy Manager cannot manage remote Duo Authentication Proxy servers, nor can you install the Proxy Manager as a stand-alone application. There is no Proxy Manager available for Linux. The Proxy Manager only functions as part of a local Duo Authentication Proxy installation on Windows servers.

Learn more about using the Proxy Manager in the Duo Authentication Proxy Reference before you continue.

To launch the Proxy Manager utility:

• Open the Start Menu and go to Duo Security.
• Click the Duo Authentication Proxy Manager icon to launch the application. You must have administrative privileges on the Windows server and accept the prompt for elevation.
• The Proxy Manager launches and automatically opens the %ProgramFiles%\Duo Security Authentication Proxy\conf\authproxy.cfg file for editing.

Use the Proxy Manager editor on the left to make the authproxy.cfg changes in these instructions. As you type into the editor, the Proxy Manager will automatically suggest configuration options. Accepting these suggestions helps make sure you use the correct option syntax.

As you follow the instructions on this page to edit the Authentication Proxy configuration, you can click Validate to verify your changes (output shown on the right).

When you complete the Authentication Proxy configuration steps in this document, you can use the Save button to write your updates to authproxy.cfg, and then use the authproxy.cfg button to start the Authentication Proxy service before continuing on to the next configuration steps.

If you do not use the Proxy Manager to edit your configuration then we recommend using WordPad or another text editor instead of Notepad when editing the config file on Windows.

Configure the Proxy for Your Primary Authenticator

In this step, you'll set up the Proxy's primary authenticator — the system which will validate users' existing passwords. Determine which type of primary authentication you'll be using, and create either an Active Directory/LDAP [ad_client] client section, or a RADIUS [radius_client] section as follows.

Active Directory

Add an [ad_client] section if you'd like to use an Active Directory domain controller (DC) or LDAP-based directory server to perform primary authentication. This section accepts the following options:

Required

search_dn=DC=example,DC=com

Optional

security_group_dn=CN=DuoVPNUsers,OU=Groups,DC=example,DC=com

For example:

[ad_client]
host=1.2.3.4
host_2=1.2.3.5
service_account_username=duoservice
service_account_password=password1
search_dn=DC=example,DC=com
security_group_dn=CN=DuoVPNUsers,OU=Groups,DC=example,DC=com

For advanced Active Directory configuration, see the full Authentication Proxy documentation.

RADIUS

To use RADIUS as your primary authenticator, add a [radius_client] section to the top of your config file. Then add the following properties to the section:

Required

Optional

For example:

[radius_client]
host=1.2.3.4
host_2=1.2.3.5
secret=radiusclientsecret

In addition, make sure that the RADIUS server is configured to accept authentication requests from the Authentication Proxy.

For advanced RADIUS configuration, see the full Authentication Proxy documentation.

Configure the Proxy for Your NetMotion Mobility

Next, you need to set up the Authentication Proxy to work with your NetMotion Mobility. Create a [radius_server_eap] section and add the properties listed below. If you've already set up the Duo Authentication Proxy for a different RADIUS EAP application, append a number to the section header to make it unique, like [radius_server_eap2].

Required

Optional

A completed config file, using Active Directory as the primary authenticator, should look something like:

[ad_client]
host=1.2.3.4
service_account_username=duoservice
service_account_password=password1
search_dn=DC=example,DC=com
 
[radius_server_eap]
ikey=DIXXXXXXXXXXXXXXXXXX
skey=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
api_host=api-XXXXXXXX.duosecurity.com
failmode=safe
client=ad_client
radius_ip_1=5.6.7.8
radius_secret_1=radiussecret1
port=1812
certs=server_cert.pem
pkey=server.key

Make sure to save your configuration file in your text editor — or validate and save in the Proxy Manager for Windows — when you're finished making changes.

Start the Proxy

net start DuoAuthProxy

authproxyctl start

net stop DuoAuthProxy & net start DuoAuthProxy

authproxyctl restart

# /opt/duoauthproxy/bin/authproxyctl start

# /opt/duoauthproxy/bin/authproxyctl status

# /opt/duoauthproxy/bin/authproxyctl restart

If you modify your authproxy.cfg configuration after initial setup, you'll need to stop and restart the Duo Authentication Proxy service or process for your change to take effect.

You can view information about your Authentication Proxy in the Authentication Proxy Dashboard.

Configure NetMotion Mobility Server

Set User Authentication Protocol to RADIUS EAP

1. Log in to the Mobility administrative interface.

2. Under the Configure tab, navigate to Authentication Settings.

3. Choose the Authentication → Protocol setting.

4. Select RADIUS - EAP (PEAP and EAP-TLS).

   

5. Click Apply.

Set RADIUS Retransmit Interval

1. Click the RADIUS: Device Authentication → Retransmit Interval setting.

2. Enter an interval long enough for a user's mobile device to receive and respond to Duo authentication requests. Recommended: at least 40000 milliseconds. If Mobility retransmits an authentication request while the Duo Authentication Proxy is waiting for the second factor it will be detected as an attempt to replay a login already in progress and rejected.

   

3. Click Apply.

4. Click the RADIUS: User Authentication → Retransmit Interval setting.

5. Change this to the same value you used for the RADIUS: Device Authentication → Retransmit Interval setting Recommended: at least 40000 milliseconds.

   

6. Click Apply.

Add RADIUS server

1. Open the RADIUS: User Authentication → Servers setting.

2. Click Add... Enter your Duo Authentication Proxy server's IP address or host name, along with the port and shared secret from the radius_server_eap section of your authproxy.cfg. Click OK.

   

3. Select and Remove any other RADIUS servers from the list to ensure that Duo authentication is always used.

   

Test Your Setup

1. Launch the Mobility client and log in with your username and password as you normally would.

   

2. Next, enter your Duo passcode or an out-of-band factor into the following prompt and click OK. You may choose from the following factor names:

   Factor	Description
   push	Perform Duo Push authentication You can use Duo Push if you've installed Duo Mobile and activated your account.
   phone	Perform phone callback authentication
   sms	Send a new batch of SMS passcodes You will need to disconnect the Mobility client after receiving the passcodes, and then and connect again, When prompted to enter your Duo factor, use one of the newly-delivered passcodes. Depending on your Mobility client configuration, you may or may not need to reenter your primary login information on the second connection.

   If you have more than one device of any type registered it's identified by the appended number. For example, push2 will send a login request to your second phone, phone3 will call your third phone, etc.

   

3. Duo will send you a push request, phone call, or SMS message and log you in after you've approved the login request or entered a valid passcode.

Troubleshooting

Need some help? Review troubleshooting tips for the Authentication Proxy and try the connectivity tool included with Duo Authentication Proxy 2.9.0 and later to discover and troubleshoot general connectivity issues.

Also take a look at our NetMotion Knowledge Base articles or Community discussions. For further assistance, contact Support.

Network Diagram

1. Primary authentication initiated to NetMotion Mobility
2. NetMotion Mobility sends authentication request to Duo Authentication Proxy
3. Primary authentication using Active Directory or RADIUS
4. Duo Authentication Proxy connection established to Duo Security over TCP port 443
5. Duo's service returns available authentication options to the proxy.
6. Duo proxy sends authentication options to NetMotion Mobility server as a RADIUS challenge.
7. User enters chosen factor when prompted by Mobility client.
8. Factor selection sent from Mobility Server to Duo's service via the Authentication Proxy.
9. Secondary authentication via Duo Security’s service
10. Duo Authentication Proxy receives authentication response
11. NetMotion Mobility access granted