Duo integrates with your Palo Alto GlobalProtect Gateway via RADIUS to add two-factor authentication to VPN logins.
Duo authentication for Palo Alto GlobalProtect supports push, phone call, or passcode authentication for GlobalProtect desktop and mobile client connections using RADIUS. This configuration does not feature the interactive Duo Prompt for web-based logins. After submitting primary username and password, users automatically receive a login request via Duo Push notification to a mobile device or as a phone call.
If you need inline self-service enrollment and the Duo Prompt for GlobalProtect SSO logins, refer to the Duo Single Sign-On for Palo Alto GlobalProtect instructions.
This application communicates with Duo's service on TCP port 443. Firewall configurations that restrict outbound access to Duo's service with rules using destination IP addresses or IP address ranges aren't recommended, since these may change over time to maintain our service's high availability. If your organization requires IP-based rules, please review this Duo KB article.
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 Palo Alto users before you begin to deploy Duo.
To integrate Duo with your Palo Alto, 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 Palo Alto, 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.
If you will set up a new Duo server, locate (or set up) a system to host the Duo Authentication Proxy installation. The proxy supports these operating systems:
See detailed Authentication Proxy operating system performance recommendations in the Duo Authentication Proxy Reference.
Then you'll need to:
The security of your Duo application is tied to the security of your secret key (skey). Secure it as you would any sensitive credential. Don't share it with unauthorized individuals or email it to anyone under any circumstances!
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.
When installing, you can choose whether or not you want to install the Proxy Manager. The Proxy Manager is a Windows utility that helps you edit the Duo Authentication Proxy configuration, determine the proxy's status, and start or stop the proxy service. Learn more about using the Proxy Manager. Installing the Proxy Manager adds about 100 MB to the installed size.
If you do not want to install the Proxy Manager, you may deselect it on the "Choose Components" installer screen before clicking Install.
To perform a silent install on Windows, issue the following from an elevated command prompt after downloading the installer (replacing version with the actual version you downloaded):
/exclude-auth-proxy-manager to install silently without the Proxy Manager:
duoauthproxy-version.exe /S /exclude-auth-proxy-manager
Ensure that Perl 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 libffi-devel perl zlib-devel diffutils
On Debian-derived systems, install these dependencies by running (as root):
$ apt-get install build-essential libffi-dev perl zlib1g-dev
If SELinux is present on your system and you want the Authentication Proxy installer to build and install its SELinux module, include
selinux-policy-devel in the dependencies:
$ yum install gcc make libffi-devel perl zlib-devel diffutils selinux-policy-devel
$ apt-get install build-essential libffi-dev perl zlib1g-dev selinux-policy-devel
Download the most recent Authentication Proxy for Unix from https://dl.duosecurity.com/duoauthproxy-latest-src.tgz. From the command line you can use
wget to download the file, like
$ wget --content-disposition https://dl.duosecurity.com/duoauthproxy-latest-src.tgz. Depending on your download method, the actual filename may reflect the version e.g. duoauthproxy-5.7.3-src.tgz. View checksums for Duo downloads here.
Extract the Authentication Proxy files and build it as follows:
$ tar xzf duoauthproxy-5.7.3-src.tgz $ cd duoauthproxy-version-src $ make
Install the authentication proxy (as root):
$ cd duoauthproxy-build $ ./install
Follow the prompts to complete the installation. The installer creates a user to run the proxy service and a group to own the log directory and files. You can accept the default user and group names or enter your own.
If SELinux is present on the target server, the Duo installer will ask you if you want to install the Authentication Proxy SELinux module. Your selection affects whether systemd can start the Authentication Proxy after installation.
|SELinux Mode||Default Response||Result|
|Enforcing||Yes||Choose 'yes' to install the Authentication Proxy's SELinux module. This permits start of the Authentication Proxy service by systemd. If you choose 'no' then the SELinux module is not installed, and systemd cannot start the Authentication Proxy service.|
|Permissive||No||Choose 'no' to decline install of the Authentication Proxy's SELinux module. The Authentication Proxy service can be started by systemd. However, if you change SELinux from permissive to enforcing mode after installing the Duo proxy, systemd can no longer start the Authentication Proxy service. If you plan to enable SELinux enforcing mode later, you should choose 'yes' to install the Authentication Proxy SELinux module now.|
To install the Duo proxy silently with the default options, use the following command:
sudo ./duoauthproxy-build/install --install-dir /opt/duoauthproxy --service-user duo_authproxy_svc --log-group duo_authproxy_grp --create-init-script yes
--enable-selinux=yes|no to the install command to choose whether to install the Authentication Proxy SELinux module.
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:
|Windows||v5.0.0 and later||
|Windows||v4.0.2 and earlier||
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:
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.
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:
%ProgramFiles%\Duo Security Authentication Proxy\conf\authproxy.cfgfile 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.
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.
[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:
The hostname or IP address of your domain controller or directory server. If this host doesn't respond to a primary authentication request and no additional hosts are specified (as
The username of a domain account that has permission to bind to your directory and perform searches. We recommend creating a service account that has read-only access.
The password corresponding to
The LDAP distinguished name (DN) of an Active Directory/LDAP container or organizational unit (OU) containing all of the users you wish to permit to log in. For example:
The hostname or IP address of a secondary/fallback domain controller or directory server, which the Authentication Proxy will use if a primary authentication request to the system defined as
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 as direct group members. Nested groups are not supported. Users who are not direct members of the specified group will not pass primary authentication. Example:
Starting with Authentication Proxy v3.2.0, the
LDAP attribute found on a user entry which will contain the submitted username. In most Active Directory configurations, it should not be necessary to change this option from the default value. OpenLDAP directories may use "uid" or another attribute for the username, which should be specified with this option.
[ad_client] host=220.127.116.11 host_2=18.104.22.168 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.
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:
The IP address of your primary RADIUS server. If this host doesn't respond to a primary authentication request and no additional hosts are specified (as
A secret to be shared between the Authentication Proxy and your existing RADIUS server. If you installed the Duo proxy on Windows and would like to encrypt this secret, see Encrypting Passwords in the full Authentication Proxy documentation.
The hostname or IP address of a secondary/fallback primary RADIUS server, which the Authentication Proxy will use if a primary authentication request to the system defined as
The authentication port on your RADIUS server. Use
If this option is set to
[radius_client] host=22.214.171.124 host_2=126.96.36.199 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.
Next, we'll set up the Authentication Proxy to work with your Palo Alto GlobalProtect. Create a
[radius_server_auto] section and add the properties listed below. If you've already set up the Duo Authentication Proxy for a different RADIUS Auto application, append a number to the section header to make it unique, like
Your Duo integration key, obtained from the details page for the application in the Duo Admin Panel.
Your Duo secret key, obtained from the details page for the application in the Duo Admin Panel. If you're on Windows and would like to encrypt the skey, see Encrypting Passwords in the full Authentication Proxy documentation.
Your Duo API hostname (e.g.
The IP address of your Palo Alto GlobalProtect. Only clients with configured addresses and shared secrets will be allowed to send requests to the Authentication Proxy.
A secret to be shared between the proxy and your Palo Alto GlobalProtect. 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.
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 on which to listen for incoming RADIUS Access Requests. If you have multiple RADIUS server sections you should use a unique port for each one.
The IP address of your second Palo Alto GlobalProtect, if you have one. You can specify additional devices as as
The secrets shared with your second Palo Alto GlobalProtect, if using one. You can specify secrets for additional devices as
Comma-separated list of additional RADIUS attributes to pass through from the primary authentication to the device integrating with the Authentication Proxy when authentication is accepted. The attribute must exist in the Authentication Proxy's RADIUS dictionary. The dictionary includes standard RADIUS attributes, as well as some vendor specific attributes from Cisco, Juniper, Microsoft, and Palo Alto. If it is not known whether the dictionary includes the specific RADIUS attribute you wish to send, use
Only valid when used with
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. Only valid when used with
A completed config file that uses Active Directory should look something like:
[ad_client] host=188.8.131.52 service_account_username=duoservice service_account_password=password1 search_dn=cn=Users,dc=example,dc=com [radius_server_auto] ikey=DIXXXXXXXXXXXXXXXXXX skey=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX api_host=api-XXXXXXXX.duosecurity.com radius_ip_1=184.108.40.206 radius_secret_1=radiussecret1 client=ad_client port=1812 failmode=safe
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.
If you installed the Duo Authentication Proxy Manager utility (available with 5.6.0 and later), click the Start Service button at the top of the Proxy Manager window to start the service.
To start the service from the command line, open an Administrator command prompt and run:
net start DuoAuthProxy
Alternatively, open the Windows Services console (
services.msc), locate "Duo Security Authentication Proxy Service" in the list of services, and click the Start Service button.
Authentication Proxy v5.1.0 and later includes the
authproxyctl executable, which shows the connectivity tool output when starting the service. The installer adds the Authentication Proxy
C:\Program Files\Duo Security Authentication Proxy\bin to your system path automatically, so you should not need to specify the full path to
authproxyctl to run it.
From an administrator command prompt run:
If the service starts successfully, Authentication Proxy service output is written to the authproxy.log file, which can be found in the
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 Duo Authentication Proxy Manager or the Windows Services console or issuing these commands from an Administrator command prompt:
net stop DuoAuthProxy & net start DuoAuthProxy
To stop and restart the Authentication Proxy using authproxyctl, from an administrator command prompt run:
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
To stop and restart the Authentication Proxy, open a root shell and run:
# /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.
Log in to the Palo Alto administrative interface.
On the Device tab, navigate to Server Profiles, then RADIUS.
Click the Add button to add a new RADIUS server profile.
In the "Name" field, enter Duo RADIUS (or another descriptive name).
Increase the "Timeout" to at least 30 (60 recommended if using push or phone authentication).
Change the "Authentication Protocol" drop-down option to PAP.
PAN-OS 7.x users must set the protocol in the CLI with this command:
set authentication radius-auth-type pap
See the PAN-OS 7.1 documentation for more information.
Under the "Servers" section, click the Add button to add a RADIUS server, and enter the following information:
|Server||Type in Duo RADIUS or any name you prefer.|
|RADIUS Server||The hostname or IP address of your Duo Authentication Proxy.|
|Secret||The RADIUS shared secret used in the Authentication Proxy configuration.|
|Port||1812 (or whichever port you configured on your Duo Authentication Proxy).|
Click OK to save the new RADIUS server profile.
On the Device tab, navigate to Authentication Profile.
Click the New... button to add a new authentication profile, and enter the following information:
|Name||Enter Duo or any name you prefer.|
|Type||Select RADIUS from the drop-down list.|
|Server Profile||Select Duo RADIUS from the drop-down list (or whatever name used to create the RADIUS Server Profile in the Add the Duo RADIUS Server section.|
|User Domain||(Optional) Depending how your users log on to GlobalProtect you may need to enter your authentication domain name here. Used in conjunction with Username Modifier. Learn more about this setting in the GlobalProtect documentation.|
|Username Modifier||(Optional) If this is blank (or set to %USERINPUT%) then the user's input is unmodified. You can prepend or append the value of User Domain (as %USERDOMAIN%) to pre-configure the username input. Learn more about this setting in the GlobalProtect documentation.|
Click the Advanced tab. In the "Allow List" section click the drop-down and select the all group (or, if you want to restrict which users may authenticate with the Duo profile, select the group of your choice).
Click OK to save the authentication profile.
On the Network tab, navigate to GlobalProtect then Gateways.
Click on your configured GlobalProtect Gateway to bring up the properties window.
On the Authentication tab of the GlobalProtect Gateway properties, select the Duo authentication profile created in Add an Authentication Profile from the available "Authentication Profile" selections for client authentication.
(Optional) If you aren't using authentication override cookies on your GlobalProtect Gateway already you may want to enable it to minimize Duo authentication requests at client reconnection during one gateway session. Refer to the GlobalProtect cookie authentication documentation to fully understand this feature before enabling it.
Click the Agent tab on the left and then click the Client Settings tab. Click on the name of your config to open it.
(Optional) On the "Authentication Override" tab check the options to both generate and accept cookies for authentication override. Set a cookie lifetime and select a certificate to use with the cookie. Note that users will not need to repeat 2FA after their initial success when reconnecting during the cookie lifetime duration.
Click OK (twice if you also enabled authentication override cookies) to save the GlobalProtect Gateway settings.
Learn more about GlobalProtect gateway configuration in the PaloAlto GlobalProtect Admin Guide.
If the GlobalProtect Portal is configured for Duo two-factor authentication, users may have to authenticate twice when connecting the GlobalProtect Gateway Agent. For the best user experience, Duo recommends leaving your GlobalProtect Portal set to use LDAP or Kerberos authentication, or if you do add Duo to your GlobalProtect Portal that you also enable cookies for authentication override on your GlobalProtect portal to avoid multiple Duo prompts for authentication when connecting.
Note that if Duo is applied only at the GlobalProtect Gateway then users may not append a factor or passcode to their password when logging in.
If your organization would like to protect the GlobalProtect Portal with Duo follow these instructions.
On the Network tab, navigate to GlobalProtect then Portal.
Click on your configured GlobalProtect Portal to bring up the properties window.
On the Authentication tab of the GlobalProtect Portal Configuration, select the Duo authentication profile created in Add an Authentication Profile from the available "Authentication Profile" selections for client authentication.
(Optional) If you aren't using authentication override cookies on your GlobalProtect Portal already you may want to enable it to minimize Duo authentication requests at client reconnection during one session.
Click the Agent tab on the left and then click on the name of your config to open it.
(Optional) On the "Authentication" tab check the options to both generate and accept cookies for authentication override. Set a cookie lifetime and select a certificate to use with the cookie.
Click OK (twice if you also enabled authentication override cookies) to save the GlobalProtect Portal settings.
Learn more about GlobalProtect gateway configuration in the PaloAlto GlobalProtect documentation.
To make your changes take effect, click the Commit button in the upper-right corner of the Palo Alto administrative interface. Once you've tested your setup, you can click Save to save the settings.
When using Duo's radius_server_auto integration with the Palo Alto GlobalProtect Gateway clients or Portal access, Duo's authentication logs may show the endpoint IP as 0.0.0.0. Palo Alto does not send the client IP address using the standard RADIUS attribute Calling-Station-Id.
A new RADIUS attribute containing the client IP address (PaloAlto-Client-Source-IP) was introduced in PAN-OS v7. Duo's Authentication Proxy supports the PaloAlto-Client-Source-IP attribute as of version 2.4.12.
To send the PaloAlto-Client-Source-IP attribute information to Duo:
Connect to the PA device administration shell and enable sending the PaloAlto-Client-Source-IP client IP attribute:
set authentication radius-vsa-on client-source-ip
When configuring the Authentication Proxy's
[radius_server_auto] authproxy.cfg settings for your Palo Alto device include the following setting:
The client IP address is sent to the Authentication Proxy as AVP 19 and is captured in Duo's authentication log.
Navigate your browser to the GlobalProtect Portal page, or attempt to connect your GlobalProtect Gateway agent.
If you applied Duo to the GlobalProtect Gateway only:
To test your setup, attempt to log in to your newly-configured system as a user enrolled in Duo with an associated Duo Push or phone authentication device.
When you enter your username and password, you will receive an automatic push or phone callback.
If you applied Duo to both the GlobalProtect Gateway and Portal:
To test your setup, attempt to log in to your newly-configured system as a user enrolled in Duo with an authentication device.
When you enter your username and password, you will receive an automatic push or phone callback.
Alternatively you may add a comma (",") to the end of your password and append a Duo factor option:
|push||Perform Duo Push authentication. You can use Duo Push if you've installed and activated Duo Mobile on your device.|
|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.|
|A numeric passcode||Log in using a passcode, either generated with Duo Mobile, sent via SMS, generated by your hardware token, or provided by an administrator. Examples: "123456" or "2345678".|
For example, if you wanted to use a passcode to authenticate instead of Duo Push or a phone call, you would enter:
username: bob password: hunter2,123456
If you wanted to use specify use of phone callback to authenticate instead of an automatic Duo Push request, you would enter:
username: bob password: hunter2,phone
You can also specify a number after the factor name if you have more than one device enrolled (as the automatic push or phone call goes to the first capable device attached to a user). So you can enter phone2 or push2 if you have two phones enrolled and you want the authentication request to go to the second phone.
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.