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Updated:September 30, 2025
Document ID:225097
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This document describes an example for TACACS+ over TLS with Cisco Identity Services Engine (ISE) as server and a Cisco IOS® XE device as client.
Overview
The Terminal Access Controller Access-Control System Plus (TACACS+) Protocol [RFC8907] enables centralized device administration for routers, network access servers, and other networked devices through one or more TACACS+ servers. It provides authentication, authorization, and accounting (AAA) services, specifically tailored for device administration use cases.
TACACS+ over TLS 1.3 [RFC8446] enhances the protocol by introducing a secure transport layer, safeguarding highly sensitive data. This integration ensures confidentiality, integrity, and authentication for the connection and network traffic between TACACS+ clients and servers.
Using this Guide
This guide divides the activities into two parts to enable ISE to manage administrative access for Cisco IOS XE based network devices. • Part 1 – Configure ISE for Device Admin • Part 2 – Configure Cisco IOS XE for TACACS+ over TLS
Prerequisites
Requirements
Requirements to configure TACACS+ over TLS:
A Certificate Authority (CA) to sign the certificate used by TACACS+ over TLS to sign the certificates ofISE and network devices.
The root certificate from the Certificate Authority (CA).
Network devices and ISE have DNS reachability and can resolve hostnames.
Components Used
The information in this document is based on these software and hardware versions:
ISE VMware virtual appliance, release 3.4 patch 2
Cisco IOS XE Software, version 17.15+
The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, ensure that you understand the potential impact of any command.
Licensing
A Device Administration license allows you to use TACACS+ services on a Policy Service node. In a high availability (HA) standalone deployment, a Device Administration license permits you to use TACACS+ services on a single Policy Service node in the HA pair.
Part 1 - Configure ISE for Device Administration
Generate Certificate Signing Request for TACACS+ Server Authentication
Step 1. Log in to the ISE admin web portal using one of the supported browsers.
By default, ISE uses a self-signed certificate for all services. The first step is to generate a Certificate Signing Request (CSR) to have it signed by our Certificate Authority (CA).
Step 2.Navigate to Administration > System > Certificates.
Step 5.Select the PSNsthat wil have TACACS+ enabled.
Step 6. Fill the Subject fields with the appropriate information.
Step 7.Add the DNS Name and IP Address under Subject Alternative Name (SAN).
Step 8.Click Generate and then Export.
Now, you can have the certificate (CRT) signed by yourCertificate Authority (CA).
Upload Root CA Certificate for TACACS+ Server Authentication
Step 1. Navigate to Administration > System > Certificates. Under Trusted Certificates, click Import.
Step 2. Select the certificate issued by the Certificate Authority (CA) that signed your TACACS Certificate Signing Request (CSR). Make sure that the option is enabled.
Step 3. Click Submit. The certificate must now appear under Trusted Certificates.
Bind the Signed Certificate Signing Request (CSR) to ISE
Once the Certificate Signing Request (CSR) is signed, you can install the signed certificate on ISE.
Step 1.Navigate to Administration > System > Certificates. Under Certificate Signing Requests, select the TACACS CSR generated in the previous step and click Bind Certificate.
Step 2.Select the signed certificate and ensure the TACACS checkbox under Usage remains selected.
Step 3.Click Submit. If you receive a warning about replacing the existing certificate, click Yes to proceed.
The certificate must now be correctly installed. You can verify this under System Certificates.
Enable TLS 1.3
TLS 1.3 is not enabled by default in ISE 3.4.x. It must be manually enabled.
Step 1.Navigate to Administration > System > Settings.
Step 2.Click Security Settings, select the checkbox next to TLS1.3 under TLS Version Settings, then click Save.
Warning: When you change the TLS version, the Cisco ISE application server restarts on all the Cisco ISE deployment machines.
Enable Device Administration on ISE
The Device Administration service (TACACS+) is not enabled by default on an ISE node. Enable TACACS+ on a PSN node.
Step 1.Navigate to Administration > System > Deployment. Select the check box next to the ISE node and clickEdit.
Step 2.Under GeneralSettings, scroll down and select the check box next to Enable Device Admin Service.
Step 3. Save the configuration. Device Admin Service is now enabled on ISE.
Enable TACACS Over TLS
Step 1.Navigate to Work Centers > Device Administration > Overview.
Step 2.Click Deployment. Select the PSNnodes where you want to enable TACACS over TLS.
Step 3.Keep the default port 6049 or specify a different TCP port for TACACS over TLS, then click Save.
Create Network Device and Network Device Groups
ISE provides powerful device grouping with multiple device group hierarchies. Each hierarchy represents a distinct and independent classification of network devices.
Step 1. Navigate to Work Centers > Device Administration > Network Resources.Click Network Device Groups and create a group with the name IOS XE.
Tip: All Device Types and All Locations are default hierarchies provided by ISE. You can add your own hierarchies and define the various components in identifying a Network Device which can be used later in the Policy Condition
Step 2.Now, add a Cisco IOS XE device as a Network Device. Navigate to Work Centers > Device Administration > Network Resources > Network Devices. Click Add to add a new Network Device. For this test, it would be SVS_BRPASR1K.
Step 3.Enter the IP address of the Device and make sure to map the Location and Device Type(IOS XE) for the Device. Finally, enable theTACACS+ over TLS Authentication Settings.
Tip: It is recommended to Enable Single Connect Mode to avoid restarting the TCP session each time a command is sent to the device.
ConfigureIdentity Stores
This section defines an Identity Store for the Device Administrators, which can be the ISE Internal Users and any supported External Identity Sources. Here uses Active Directory (AD), an External Identity Source.
Step1. Navigate to Administration > Identity Management > External Identity Stores > Active Directory. Click Add to define a new AD Joint Point.
Step 2. Specify the Join Point name and the AD domain name and click Submit.
Step 3. Click Yes when prompted Would you like to Join all ISE Nodes to this Active Directory Domain?
Step 4. Input the credentials with AD join privileges, and Join ISE to AD. Check the Status to verify it operational.
Step 5. Navigate to the Groups tab, and click Add to get all the groups needed based on which the users are authorized for the device access. This example shows the groups used in the Authorization Policy in this guide
ConfigureTACACS+ Profiles
You are going to map the TACACS+ Profiles to the two main user roles on the Cisco IOS XE devices:
Root System Administrator – This is the highest-privileged role in the device. The user with the root system administrator role has full administrative access to all system commands and configuration capabilities.
Operator –This role is intended for users who need read-only access to the system for monitoring and troubleshooting purposes.
These are defined as two TACACS+ Profiles: IOS XE_RW and IOSXR_RO.
IOS XE_RW - Administrator Profile
Step 1 Navigate to Work Centers > Device Administration > Policy Elements > Results > TACACS Profiles. Add a new TACACS Profile and name it IOS XE_RW.
Step 2. Check and set the Default Privilege and Maximum Privilege as 15.
Step 3.Confirm the config and Save.
IOS XE_RO - Operator Profile
Step 1 Navigate to Work Centers > Device Administration > Policy Elements > Results > TACACS Profiles. Add a new TACACS Profile and name it IOS XE_RO.
Step 2. Check and set the Default Privilege and Maximum Privilege as 1.
Step 3.Confirm the config and Save.
ConfigureTACACS+ Command Sets
these are defined as two TACACS+ Commands Sets: CISCO_IOS XE_RW and CISCO_IOS XE_RO.
CISCO_IOS XE_RW - Administrator Command Set
Step 1. Navigate to Work Centers > Device Administration > Policy Elements > Results > TACACS Command Sets. Add a new TACACS Command Set and name it CISCO_IOS XE_RW.
Step 2. Check the Permit any command that is not listed below checkbox (this allows any command for the administrator role) and click Save.
CISCO_IOS XE_RO - Operator Command Set
Step 1 From ISE UI, navigate to Work Centers > Device Administration > Policy Elements > Results > TACACS Command Sets. Add a new TACACS Command Set and name it CISCO_IOS XE_RO.
Step 2. In Commands section, add a new command.
Step 3. Select Permit from the dropdown list for Grant column and enter show on the Command column; and click the checkarrow.
Step 4. Confirm the data and click Save.
ConfigureDevice Admin Policy Sets
Policy Sets are enabled by default for Device Administration. Policy Sets can divide polices based on the Device Types so to ease application of TACACS profiles.
Step 1.Navigate to Work Centers > Device Administration > Device Admin Policy Sets. Add a new Policy Set IOS XE Devices. Under condition specify DEVICE:Device Type EQUALS All Device Types#IOS XE. Under Allowed Protocols, select Default Device Admin.
Step 2.Click Save and click the right arrow to configure this Policy Set.
Step 3.Create the Authentication Policy. For Authentication, you use the AD as the ID Store. Leave the default options under If Auth fail, If User not found and If Process fail.
Step 4. Define the Authorization Policy.
Create the authorization policy based on user groups in Active Directory (AD).
For Example:
• Users in the AD group Device RO are assigned the CISCO_IOSXR_RO Command Set and the IOSXR_RO Shell Profile.
• Users in the AD group Device Admin are assigned the CISCO_IOSXR_RW Command Set and the IOSXR_RW Shell Profile.
Part 2 - Configure Cisco IOS XE for TACACS+ over TLS 1.3
Caution: Ensure that the console connection is reachable and functioning properly.
Tip: It is recommended to configure a temporary user and change the AAA authentication and authorization methods to use local credentials instead of TACACS while making configuration changes, to avoid being locked out of the device.
% The subject name in the certificate will include: C=US,ST=NC,L=RTP,O=Cisco,OU=SVS,CN=cat9k.svs.lab % The subject name in the certificate will include: cat9k.svs.lab Display Certificate Request to terminal? [yes/no]: yes Certificate Request follows:
! Below debugs will be needed only if there is any issue with SSL Handshake debug ip tcp transactions debug ip tcp packet debug crypto pki transactions debug crypto pki API debug crypto pki messages debug crypto pki server debug ssl openssl errors debug ssl openssl msg debug ssl openssl states clear logging