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Microsoft Forefront Unified Access Gateway (UAG)

Duo integrates with your Microsoft UAG Gateway to add two-factor authentication to portal logins.

First Steps

To integrate Duo with your Microsoft UAG server, you will need to install a local proxy service on a machine within your network. Before proceeding, you should locate (or set up) a system on which you will install the Duo Authentication Proxy. The proxy supports Windows and Linux systems (in particular, we recommend Windows Server 2012 R2 or later, Red Hat Enterprise Linux 6 or later, CentOS 6 or later, or Debian 6 or later).

This Duo proxy server also acts as a RADIUS server — there's no need to deploy a separate RADIUS server to use Duo.

Then you'll need to:

  1. Sign up for a Duo account.
  2. Log in to the Duo Admin Panel and navigate to Applications.
  3. Click Protect an Application and locate Microsoft UAG in the applications list. Click Protect this Application to get your integration key, secret key, and API hostname. See Getting Started for help.
Connectivity Requirements

This integration communicates with Duo's service on TCP port 443. Also, we do not recommend locking down your firewall to individual IP addresses, since these may change over time to maintain our service's high availability.

Install the Duo Authentication 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).

  1. Download the most recent Authentication Proxy for Windows from Note that the actual filename will reflect the version e.g. duoauthproxy-2.4.19.exe.
  2. Launch the Authentication Proxy installer on the target Windows server as a user with administrator rights and follow the on-screen prompts.
  1. Ensure that OpenSSL, Python 2.6 or 2.7 (including development headers and libraries), and a compiler toolchain are installed. On most recent RPM-based distributions — like Fedora, RedHat Enterprise, and CentOS — you can install these by running (as root):

    $ yum install gcc make openssl-devel python-devel libffi-devel

    On Debian-derived systems, install these dependencies by running (as root):

    $ apt-get install build-essential libssl-dev python-dev libffi-dev

    To ensure that your Python version will work with the Authentication Proxy, run:

    $ python --version

    If the output does not say "Python 2.6.x" or "Python 2.7.x", first take note that many distributions can support multiple versions of python simultaneously. If your python installation does not appear to be a supported version, try replacing "python" in the above command with "python2.6" or "python2.7". If neither of these work, then you will need to install a different version of Python. You may need to search additional repositories for your distribution (e.g. for Centos or Red Hat Enterprise Linux, Extra Packages for Enterprise Linux), or build Python from source.

  2. Download the most recent Authentication Proxy for Unix from Depending on your download method, the actual filename may reflect the version e.g. duoauthproxy-2.4.19-src.tgz.

  3. Extract the Authentication Proxy files and build it as follows:

    $ tar xzf duoauthproxy-latest-src.tgz
    $ cd duoauthproxy-version-src
    $ export PYTHON=python_command
    $ make
    Where python_command is the command to run a Python 2.6 or Python 2.7 interpreter (e.g. "python", "python2.6", "python2.7").
  4. Install the authentication proxy (as root):

    $ cd duoauthproxy-build
    $ ./install

    Follow the prompts to complete the installation.

If you ever need to uninstall the proxy, run /opt/duoauthproxy/uninstall.

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:

Platform Default Configuration Path
Windows (64-bit) C:\Program Files (x86)\Duo Security Authentication Proxy\conf\authproxy.cfg
Windows (32-bit) C:\Program Files\Duo Security Authentication Proxy\conf\authproxy.cfg
Linux /opt/duoauthproxy/conf/authproxy.cfg

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


Individual properties beneath a section appear as:


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. 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. In most cases, this means configuring the Proxy to communicate with Active Directory or RADIUS.

Active Directory

To use Active Directory as your primary authenticator, add an [ad_client] section to the top of your config file. Add the following properties to the section:


host The hostname or IP address of your domain controller.
service_account_username The username of a domain member account that has permission to bind to your Active Directory and perform searches. We recommend creating a service account that has read-only access.
service_account_password The password corresponding to service_account_username. If you're on Windows and would like to encrypt this password, see Encrypting Passwords in the full Authentication Proxy documentation.

The LDAP distinguished name (DN) of an Active Directory container or organizational unit (OU) containing all of the users you wish to permit to log in. For example:



host_2 The hostname or IP address of a secondary/fallback domain controller. You can add additional domain controllers as host_3, host_4, etc.

To further restrict access, specify the LDAP distinguished name (DN) of a security group that contains the users who should be able to log in. Other users will not pass primary authentication. For example:


For example:


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


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:


host The IP address of your RADIUS server. You can add backup servers with host_2, host_3, etc.
secret A secret to be shared between the Authentication Proxy and your existing RADIUS server. If you're on Windows and would like to encrypt this secret, see Encrypting Passwords in the full Authentication Proxy documentation.


port The authentication port on your RADIUS server. By default, the proxy will attempt to contact your RADIUS server on port 1812. Use port_2, port_3, etc. to specify ports for the backup servers.
pass_through_all If this option is set to "true", all RADIUS attributes set by the primary authentication server will be copied into RADIUS responses sent by the proxy. Default: "false"

For example:


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 Microsoft UAG

Next, we'll set up the Authentication Proxy to work with your Microsoft UAG. Create a [radius_server_auto] section with the following properties:


ikey Your integration key.
skey Your secret key.
api_host Your API hostname (e.g. "").
radius_ip_1 The IP address of your Microsoft UAG.
radius_secret_1 A secret to be shared between the proxy and your Microsoft UAG. If you're on Windows and would like to encrypt this secret, see Encrypting Passwords in the full Authentication Proxy documentation.

The mechanism that the Authentication Proxy should use to perform primary authentication. This should correspond with a "client" section elsewhere in the config file.

"ad_client" Use Active Directory for primary authentication. Make sure you have an [ad_client] section configured.
"radius_client" Use RADIUS for primary authentication. Make sure you have a [radius_client] section configured.
"duo_only_client" Do not perform primary authentication. Make sure you have a [duo_only_client] section configured.

This parameter is optional if you only have one "client" section. If you have multiple, each "server" section should specify which "client" to use.


port The port on which to listen for incoming RADIUS Access Requests. Default: 1812.

Either "safe" or "secure":

"safe" In the event that Duo's service cannot be contacted, users' authentication attempts will be permitted if primary authentication succeeds. This is the default.
"secure" In the event that Duo's service cannot be contacted, all users' authentication attempts will be rejected.
radius_ip_2 The IP address of your second Microsoft UAG, if you have one. You can specify additional devices as as radius_ip_3, radius_ip_4, etc.
radius_secret_2 The secrets shared with your second Microsoft UAG, if using one. You can specify secrets for additional devices as radius_secret_3, radius_secret_4, etc. If you're on Windows and would like to encrypt this secret, see Encrypting Passwords in the full Authentication Proxy documentation.

A completed config file that uses Active Directory should look something like:


Make sure to save your configuration file when done.


View video guides for proxy deployment at the Authentication Proxy Overview or see the Authentication Proxy Reference Guide for additional configuration options.

Start the Proxy

Open an Administrator command prompt and run:

net start DuoAuthProxy

Alternatvely, open the Windows Services console (services.msc), locate "Duo Security Authentication Proxy Service" in the list of services, and click the Start Service button.

If the service starts successfully, Authentication Proxy service output is written to the authproxy.log file, which can be found in the log subdirectory.

If you see an error saying that the "service could not be started", open the Application Event Viewer and look for an Error from the source "DuoAuthProxy". The traceback may include a "ConfigError" that can help you find the source of the issue.

Stop and restart the Authentication Proxy service by either clicking the Restart Service button in the Windows Services console or issuing these commands from an Administrator command prompt:

net stop DuoAuthProxy & net start DuoAuthProxy

Open a root shell and run:

# /opt/duoauthproxy/bin/authproxyctl start

To ensure the proxy started successfully, run:

# /opt/duoauthproxy/bin/authproxyctl status

Authentication Proxy service output is written to the authproxy.log file, which can be found in the log subdirectory.

To stop and restart the Authentication Proxy, open a root shell and run:

# /opt/duoauthproxy/bin/authproxyctl restart

Configure Your Microsoft UAG Gateway

This configuration has been tested with UAG 2010 SP 3 on Windows 2008 R2.

Add the Duo RADIUS server

  1. Open the Forefront UAG Management console from your Start menu.

  2. Navigate to Authentication and Authorization Servers from the Admin menu drop-down in the UAG Management Console.

  3. In the Authentication and Authorization Servers window click the Add... button.

  4. In the Add Authentication Server dialog, set the Server type to RADIUS by selecting from the drop-down, and enter a name for the RADIUS server. Enter the IP address or host name of the server where you configured the Duo Authentication Proxy, set the port to 1812 or whichever port you used in the authproxy config file, and enter the secret from the authproxy.cfg file. Ensure that the Support challenge-response mode option is checked and click OK.

    Add new RADIUS Authentication Server

  5. Click the Close button in the Authentication and Authorization Servers window.

Modify the HTTPS Connection

  1. Navigate to your HTTPS Connection under Forefront UAG > HTTPS Connections. On the settings page for your trunk, click the Configure... button in the Trunk Configuration section.

    Configure trunk

  2. In the Advanced Trunk Configuration window, go to the Authentication tab. Check the box next to Require users to authenticate at session logon and click the Add... button. Select the RADIUS server you added in step 4 and click the Select button.

    Select the Duo server

    For the most secure configuration and optimal end-user experience, the Duo RADIUS server should be the only authentication server available. If other authentication servers are configured users may be able to bypass two-factor authentication or could be prompted twice to log in to the UAG portal.

    Configure trunk

  3. The default login timeout for UAG is 16 seconds. Increase the timeout to 60 seconds to give users more time to complete Duo authentication. Open the Registry Editor (regedit.exe) and navigate to the key HKEY_LOCAL_MACHINE\SOFTWARE\WhaleCom\e-Gap\von\UrlFilter\Auth\Radius. Edit the UDPReqTimeout value and set to to 3c (hexadecimal) or 60 (decimal). Close the Registry Editor after making the change.

    Increase timeout

  4. In the main UAG Management console window go to File > Save or click the purple disk "Save Configuration" icon to save the configuration changes, then go to File > Activate or click the silver gear "Activate configuration" icon to apply the updated configuration. You can choose to backup the existing configuration before applying changes.

Test Your Setup

Go to the URL or IP address where your UAG Gateway is listening.

To test your setup, attempt to log in to your newly-configured system. When you enter your username and password, you will receive an automatic push or phone callback. Alternatively you can add a comma (",") to the end of your password, followed by a Duo passcode.

For example, given a username 'bob', with password 'password123' and a Duo passcode '123456', you would enter:

username: bob
password: password123,123456

In addition, you may also enter the name of an out-of-band factor in lieu of a passcode. You may choose from the following factor names:

push Perform Duo Push authentication
You can use Duo Push if you've installed Duo Mobile and added your account to it
phone Perform phone callback authentication
sms Send a new batch of SMS passcodes
Your authentication attempt will be denied. You can then authenticate with one of the newly-delivered passcodes.

Returning to the previous example, if you wanted to use Duo Push (rather than a passcode) to authenticate, you would enter:

username: bob
password: password123,push

You can also specify a number after the factor name if you have more than one device enrolled. So you can enter phone2 or push2 if you have two phones enrolled.


Need some help? Take a look at our UAG Knowledge Base articles or Community discussions. For further assistance, contact Support.

Network Diagram

  1. Primary authentication initiated to UAG Server
  2. UAG Server sends authentication request to Duo Security’s authentication proxy
  3. Primary authentication using Active Directory or RADIUS
  4. Duo authentication proxy connection established to Duo Security over TCP port 443
  5. Secondary authentication via Duo Security’s service
  6. Duo authentication proxy receives authentication response
  7. UAG access granted

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