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 Palo Alto Networks SSO instructions. GlobalProtect SSO requires that you deploy a SAML 2.0 identity provider on your network.
Learn more about the differences between these two Palo Alto GlobalProtect deployment configurations.
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, available methods for enrolling Duo users, and Duo policy settings and how to apply them. 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.
Next, locate (or set up) a system on which you will install the Duo Authentication Proxy. The proxy supports these operating systems:
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!
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).
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-develOn Debian-derived systems, install these dependencies by running (as root):
$ apt-get install build-essential libffi-dev perl zlib1g-devDownload the most recent Authentication Proxy for Unix from https://dl.duosecurity.com/duoauthproxy-latest-src.tgz. Depending on your download method, the actual filename may reflect the version e.g. duoauthproxy-5.1.0-src.tgz. View checksums for Duo downloads here.
Extract the Authentication Proxy files and build it as follows:
$ tar xzf duoauthproxy-latest-src.tgz
$ cd duoauthproxy-version-src
$ makeInstall the authentication proxy (as root):
$ cd duoauthproxy-build
$ ./installFollow 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 you ever need to uninstall the proxy, run /opt/duoauthproxy/uninstall.
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=valueThe 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.
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.
To use Active Directory/LDAP as your primary authenticator, add an [ad_client] section to the top of your config file. Add the following properties to the section:
Required
host
|
The hostname or IP address of your domain controller. |
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. |
service_account_password
|
The password corresponding to |
search_dn
|
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: |
Optional
host_2
|
The hostname or IP address of a secondary/fallback domain controller. You can add additional domain controllers as |
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: Starting with Authentication Proxy v3.2.0, the |
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=comFor 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:
Required
host
|
The IP address of your RADIUS server. You can add backup servers with |
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. |
Optional
port
|
The authentication port on your RADIUS server. Use Default: |
pass_through_all
|
If this option is set to Default: |
For example:
[radius_client]
host=1.2.3.4
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 [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. |
||||
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.
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. Default: |
||||||
failmode
|
Either
Default: |
||||||
radius_ip_2
|
The IP address of your second Palo Alto GlobalProtect, if you have one. You can specify additional devices as as |
||||||
radius_secret_2
|
The secrets shared with your second Palo Alto GlobalProtect, if using one. You can specify secrets for additional devices as |
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=safeMake 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.
Open an Administrator command prompt and run:
net start DuoAuthProxyAlternatively, 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 startIf 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 DuoAuthProxyTo stop and restart the Authentication Proxy using authproxyctl, from an administrator command prompt run:
authproxyctl restartOpen a root shell and run:
# /opt/duoauthproxy/bin/authproxyctl startTo ensure the proxy started successfully, run:
# /opt/duoauthproxy/bin/authproxyctl statusAuthentication 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 restartIf 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.
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:
| 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). |
Click OK to save the new RADIUS server profile.
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. |
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 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 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-ipWhen configuring the Authentication Proxy's [radius_server_auto] authproxy.cfg settings for your Palo Alto device include the following setting:
client_ip_attr=paloaltoThe 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 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: password123,123456In 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 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. |
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 (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.
Also take a look at our Palo Alto Knowledge Base articles or Community discussions. For further assistance, contact Support.
