Duo integrates with your Cisco ISE to add two-factor authentication.
The Cisco ISE instructions support push, phone call, or passcode authentication. This configuration does not feature the interactive Duo Prompt for web-based logins, but does capture client IP information for use with Duo policies, such as geolocation and authorized networks.
Before starting, make sure that Duo is compatible with your Cisco ISE device. Log on to your Cisco ISE via the web interface and verify that your Cisco ISE firmware is version 2.4 or later.
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 Cisco ISE users before you begin to deploy Duo.
To integrate Duo with your Cisco ISE, you will need to install a local proxy service on a machine within your network. This Duo proxy server also acts as a RADIUS server — there's usually no need to deploy a separate RADIUS server to use 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, 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 python-devel libffi-devel perl zlib-devel
On Debian-derived systems, install these dependencies by running (as root):
$ apt-get install build-essential python-dev libffi-dev perl zlib1g-dev
Download 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-3.1.1-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 $ 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 you ever need to uninstall the proxy, run
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|
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.
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 as your primary authenticator, add an
[ad_client] section to the top of your config file. Add the following properties to the section:
||The hostname or IP address of your domain controller.|
||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.|
The password corresponding to
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:
The hostname or IP address of a secondary/fallback domain controller. You can add additional domain controllers 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. Other users will not pass primary authentication. For example:
[ad_client] host=22.214.171.124 host_2=126.96.36.199 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 RADIUS server. You can add backup servers with
||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.|
The authentication port on your RADIUS server. By default, the proxy will attempt to contact your RADIUS server on port 1812. Use
||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"|
[radius_client] host=188.8.131.52 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 Cisco ISE. Create a
[radius_server_auto] section with the following properties:
||Your integration key.|
||Your secret key.|
||Your API hostname (e.g. "api-XXXXXXXX.duosecurity.com").|
||The IP address of your Cisco ISE.|
||A secret to be shared between the proxy and your Cisco ISE. 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.
||The port on which to listen for incoming RADIUS Access Requests. Default: 1812.|
Either "safe" or "secure":
The IP address of your second Cisco ISE, if you have one. You can specify additional devices as as
The secrets shared with your second Cisco ISE, 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=184.108.40.206 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=220.127.116.11 radius_secret_1=radiussecret1 client=ad_client port=1812 failmode=safe
Make sure to save your configuration file when done.
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.
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
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.
Navigate to Administration → Network Resources → External RADIUS Servers and click Add.
Fill in the Name with DuoRADIUS and enter the following information:
|Host IP||The hostname or IP address of your Duo Authentication Proxy|
|Shared Secret||Shared Secret used in Authentication Proxy configuration|
|Authentication Port||1812 (or whichever port specified in your authproxy.cfg file)|
|Server Timeout||60 seconds should be sufficient to complete authentication.|
Click Save to add the new server.
Navigate to Administration → Network Resources → RADIUS Server Sequence and click Add.
Fill in the Name with DuoRADIUSSequence, select the newly added DuoRADIUS server within the Available selection, and click the arrow to add your DuoRADIUS server to the Selected section.
Click Save to apply the change.
Navigate to Policy → Policy Sets.
Click the drop down of the policy set you wish to change and select DuoRADIUSSequence.
Click Save to apply the change.
Launch the AnyConnect client (or any network device that utilizes Cisco ISE for a AAA server) and select the profile that now uses Duo RADIUS authentication.
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: password123,123456
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:
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.|
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.