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Duo Two-Factor Authentication for Palo Alto GlobalProtect RADIUS

Last Updated: March 10th, 2023

Duo integrates with your Palo Alto GlobalProtect Gateway via RADIUS to add two-factor authentication to VPN logins.

Overview

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.

Learn more about the differences between these two Palo Alto GlobalProtect deployment configurations.

Connectivity Requirements

This application communicates with Duo's service on SSL 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 Duo Knowledge Base article 1337.

Effective June 30, 2023, Duo no longer supports TLS 1.0 or 1.1 connections or insecure TLS/SSL cipher suites. See Duo Knowledge Base article 7546 for additional guidance.

Walkthrough Video

 

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 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.

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.
  3. Click Protect an Application and locate the entry for Palo Alto SSL VPN 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.
Treat your secret key like a password

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!

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.

  1. Download the most recent Authentication Proxy for Windows from https://dl.duosecurity.com/duoauthproxy-latest.exe. Note that the actual filename will reflect the version e.g. duoauthproxy-6.4.1.exe. View checksums for Duo downloads here.
  2. Launch the Authentication Proxy installer on the target Windows server as a user with administrator rights and follow the on-screen prompts.

    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.

Silent 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):

duoauthproxy-version.exe /S

Append /exclude-auth-proxy-manager to install silently without the Proxy Manager:

duoauthproxy-version.exe /S /exclude-auth-proxy-manager
  1. Ensure that Perl and a compiler toolchain are installed. On most recent RPM-based distributions — like Fedora, Red Hat 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 and chkconfig in the dependencies:

    $ yum install gcc make libffi-devel perl zlib-devel diffutils selinux-policy-devel chkconfig
    $ apt-get install build-essential libffi-dev perl zlib1g-dev selinux-policy-devel chkconfig
  2. Download the most recent Authentication Proxy for Unix from https://dl.duosecurity.com/duoauthproxy-latest-src.tgz. From the command line you can use curl or 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-6.4.1-src.tgz. View checksums for Duo downloads here.

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

    $ tar xzf duoauthproxy-6.4.1-src.tgz
    $ cd duoauthproxy-version-src
    $ make
  4. 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.

    If you choose to install the Authentication Proxy SELinux module and the dependencies selinux-policy-devel and chkconfig are not present, then the installer fails to build the module.

    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.
Silent Install

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

Append --enable-selinux=yes|no to the install command to choose whether to install the Authentication Proxy SELinux module.

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:

Operating System Authentication
Proxy Version
Path
Windows v5.0.0 and later C:\Program Files\Duo Security Authentication Proxy\conf\authproxy.cfg
Windows v4.0.2 and earlier C:\Program Files (x86)\Duo Security Authentication Proxy\conf\authproxy.cfg
Linux All /opt/duoauthproxy/conf/authproxy.cfg

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

host

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 host_2, host_3, etc.) then the user's login attempt fails.

service_account_username

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.

This parameter not required when using SSPI authentication; see the auth_type optional parameter description in the Authentication Proxy Reference for more information.

service_account_password

The password corresponding to service_account_username. If you installed the Duo proxy on Windows and would like to encrypt this password, see Encrypting Passwords in the full Authentication Proxy documentation.

This parameter not required when using SSPI authentication; see the auth_type optional parameter description in the Authentication Proxy Reference for more information.

search_dn

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:

search_dn=DC=example,DC=com

Optional

host_2

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 host times out. You can add additional servers as fallback hosts by specifying them as as host_3, host_4, etc.

security_group_dn

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:

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

Starting with Authentication Proxy v3.2.0, the security_group_dn may be the DN of an AD user's primarygroup. Prior versions do not support primary groups.

username_attribute

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.

Default: "sAMAccountName"

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

host

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 host_2, host_3, etc.) then the user's login attempt fails.

secret

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.

Optional

host_2

The 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 host times out. You can add additional servers as fallback hosts by specifying them as as host_3, host_4, etc.

port

The authentication port on your RADIUS server. Use port_2, port_3, etc. to specify ports for the backup servers.

Default:1812

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:

[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 Palo Alto GlobalProtect

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 [radius_server_auto2].

Required

ikey

Your Duo integration key, obtained from the details page for the application in the Duo Admin Panel.

skey

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.

api_host

Your Duo API hostname (e.g. api-XXXXXXXX.duosecurity.com), obtained from the details page for the application in the Duo Admin Panel.

radius_ip_1

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.

radius_secret_1

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.

client

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/LDAP 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.

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

Optional

port

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. If you have another service running on the server where you installed Duo that is using the default RADIUS port 1812, you will need to set this to a different port number to avoid a conflict.

Default: 1812

failmode

Either safe or secure:

Failmode

Description

safe

In the event that Duo's service cannot be contacted, users' authentication attempts will be permitted if primary authentication succeeds.

secure

In the event that Duo's service cannot be contacted, all users' authentication attempts will be rejected.

Default: safe

radius_ip_2

The IP address of your second Palo Alto GlobalProtect, 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 Palo Alto GlobalProtect, 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.

pass_through_attr_names

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 pass_through_all instead.

Only valid when used with radius_client. By default, the proxy will create a new Accept message without passing through any attributes.

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. Only valid when used with radius_client.

Default: "false"

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

[ad_client]
host=1.2.3.4
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=5.6.7.8
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.

Note

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

Start the Proxy

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:

authproxyctl start

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 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:

authproxyctl restart

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

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 Your Palo Alto GlobalProtect Gateway

Add the Duo RADIUS server

  1. Log in to the Palo Alto administrative interface.

  2. On the Device tab, navigate to Server Profiles, then RADIUS.

  3. Click the Add button to add a new RADIUS server profile.

  4. In the "Name" field, enter Duo RADIUS (or another descriptive name).

  5. Increase the "Timeout" to at least 30 (60 recommended if using push or phone authentication).

  6. 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 documentation for more information.

  7. Under the "Servers" section, click the Add button to add a RADIUS server, and enter the following information:

    Setting Value
    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).
  8. Click OK to save the new RADIUS server profile.

    RADIUS Server Profile

Add an Authentication Profile

  1. On the Device tab, navigate to Authentication Profile.

  2. Click the New... button to add a new authentication profile, and enter the following information:

    Setting Value
    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.
  3. 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).

  4. Click OK to save the authentication profile.

    Authentication Profile

Configure GlobalProtect Gateway

  1. On the Network tab, navigate to GlobalProtect then Gateways.

  2. Click on your configured GlobalProtect Gateway to bring up the properties window.

  3. 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.

    GlobalProtect Gateway Properties
  4. (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.

  5. (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.

    GlobalProtect Gateway Properties
  6. 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.

Configure GlobalProtect Portal

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.

  1. On the Network tab, navigate to GlobalProtect then Portal.

  2. Click on your configured GlobalProtect Portal to bring up the properties window.

  3. 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.

    GlobalProtect Portal Properties
  4. (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.

  5. (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.

    GlobalProtect Portal Properties
  6. 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.

Commit and Save Your Settings

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.

Client IP Reporting

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:

  1. 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
  2. When configuring the Authentication Proxy's [radius_server_auto] authproxy.cfg settings for your Palo Alto device include the following setting:

    client_ip_attr=paloalto

The client IP address is sent to the Authentication Proxy as AVP 19 and is captured in Duo's authentication log.

Test Your Setup

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.

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 Palo Alto Knowledge Base articles or Community discussions. For further assistance, contact Support.

Network Diagram

Palo Alto Network Diagram
  1. Primary authentication initiated to Palo Alto Global Protect
  2. Palo Alto Global Protect 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. Palo Alto Global Protect access granted