Published On: August 6ᵗʰ, 2019 02:04

TACACS+ Configuration Guide, Cisco IOS XE Release 3S

The Per VRF for TACACS+ Servers feature allows per virtual route forwarding (per VRF) to be configured for authentication, authorization, and accounting (AAA) on TACACS+ servers.

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table at the end of this module.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/​go/​cfn. An account on Cisco.com is not required.

Prerequisites for Per VRF for TACACS Servers

  • TACACS+ server access is required.
  • Experience configuring TACACS+, AAA and per VRF AAA, and group servers is necessary.

Restrictions for Per VRF for TACACS Servers

  • The VRF instance must be enabled globally on the router before per VRF for a TACACS+ server is configured.

Information About Per VRF for TACACS Servers

Per VRF for TACACS Servers Overview

The Per VRF for TACACS+ Servers feature allows per VRF AAA to be configured on TACACS+ servers. Prior to Cisco IOS XE Release 2.2, this functionality was available only on RADIUS servers.

How to Configure Per VRF for TACACS Servers

Configuring Per VRF on a TACACS Server

The initial steps in this procedure are used to configure AAA and a server group, create a VRF routing table, and configure an interface. Steps 10 through 13 are used to configure the per VRF on a TACACS+ server feature:

SUMMARY STEPS

1. enable

2. configure terminal

3. ip vrf vrf-name

4. rd route-distinguisher

5. exit

6. interface interface-name

7. ip vrf forwarding vrf-name

8. ip address ip-address mask [secondary]

9. exit

10. aaa group server tacacs+ group-name

11. server-private {ip-address | name} [nat] [single-connection] [port port-number] [timeout seconds] [key [0 | 7] string]

12. ip vrf forwarding vrf-name

13. ip tacacs source-interface subinterface-name

14. exit


DETAILED STEPS
  Command or Action Purpose
Step 1 enable


Example:
Router> enable
 

Enables privileged EXEC mode.

  • Enter your password if prompted.
 
Step 2 configure terminal


Example:
Router# configure terminal
 

Enters global configuration mode.

 
Step 3 ip vrf vrf-name


Example:
Router (config)# ip vrf cisco
 

Configures a VRF table and enters VRF configuration mode.

 
Step 4 rd route-distinguisher


Example:
Router (config-vrf)# rd 100:1
 

Creates routing and forwarding tables for a VRF instance.

 
Step 5 exit


Example:
Router (config-vrf)# exit
 

Exits VRF configuration mode.

 
Step 6 interface interface-name


Example:
Router (config)# interface Loopback0
 

Configures an interface and enters interface configuration mode.

 
Step 7 ip vrf forwarding vrf-name


Example:
Router (config-if)# ip vrf forwarding cisco
 

Configures a VRF for the interface.

 
Step 8 ip address ip-address mask [secondary]


Example:
Router (config-if)# ip address 10.0.0.2 255.0.0.0
 

Sets a primary or secondary IP address for an interface.

 
Step 9 exit


Example:
Router (config-if)# exit
 

Exits interface configuration mode.

 
Step 10 aaa group server tacacs+ group-name


Example:
Router (config)# aaa group server tacacs+ tacacs1
 

Groups different TACACS+ server hosts into distinct lists and distinct methods and enters server-group configuration mode.

 
Step 11 server-private {ip-address | name} [nat] [single-connection] [port port-number] [timeout seconds] [key [0 | 7] string]


Example:
Router (config-sg-tacacs+)# server-private 10.1.1.1 port 19 key cisco
 

Configures the IP address of the private TACACS+ server for the group server.

 
Step 12 ip vrf forwarding vrf-name


Example:
Router (config-sg-tacacs+)# ip vrf forwarding cisco
 

Configures the VRF reference of a AAA TACACS+ server group.

 
Step 13 ip tacacs source-interface subinterface-name


Example:
Router (config-sg-tacacs+)# ip tacacs source-interface Loopback0
 

Uses the IP address of a specified interface for all outgoing TACACS+ packets.

 
Step 14 exit


Example:
Router (config-sg-tacacs)# exit
 

Exits server-group configuration mode.

 

Verifying Per VRF for TACACS Servers

To verify the per VRF TACACS+ configuration, perform the following steps:


Note


The debug commands may be used in any order.



Caution


Enabling debug CLI can cause performance degradation on the router. Use of debug commands for large number of sessions is not recommended.


SUMMARY STEPS

1. enable

2. debug tacacs authentication

3. debug tacacs authorization

4. debug tacacs accounting

5. debug tacacs packets


DETAILED STEPS
  Command or Action Purpose
Step 1 enable


Example:
Router> enable
 

Enables privileged EXEC mode.

  • Enter your password if prompted.
 
Step 2 debug tacacs authentication


Example:
Router# debug tacacs authentication
 

Displays information about AAA/TACACS+ authentication.

 
Step 3 debug tacacs authorization


Example:
Router# debug tacacs authorization
 

Displays information about AAA/TACACS+ authorization.

 
Step 4 debug tacacs accounting


Example:
Router# debug tacacs accounting
 

Displays information about accountable events as they occur.

 
Step 5 debug tacacs packets


Example:
Router# debug tacacs packets
 

Displays information about TACACS+ packets.

 

Configuration Examples for Per VRF for TACACS Servers

Configuring Per VRF for TACACS Servers Example

The following output example shows that the group server tacacs1 is configured for per VRF AAA services:

aaa group server tacacs+ tacacs1
    server-private 10.1.1.1 port 19 key cisco
    ip vrf forwarding cisco
    ip tacacs source-interface Loopback0
  ip vrf cisco
   rd 100:1
  interface Loopback0
   ip address 10.0.0.2 255.0.0.0
   ip vrf forwarding cisco

Additional References

The following sections provide references related to Per VRF for TACACS+ Servers..

Related Documents

Related Topic

Document Title

Configuring TACACS+

Configuring TACACS+ module.

Per VRF AAA

Per VRF AAA module.

Security commands

Cisco IOS Security Command Reference

Standards

Standard

Title

No new or modified standards are supported by this feature, and support for existing standards has not been modified by this feature.

--

MIBs

MIB

MIBs Link

No new or modified MIBs are supported by this feature, and support for existing MIBs has not been modified by this feature.

To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:

http:/​/​www.cisco.com/​go/​mibs

RFCs

RFC

Title

No new or modified RFCs are supported by this feature, and support for existing RFCs has not been modified by this feature.

--

Technical Assistance

Description

Link

The Cisco Support website provides extensive online resources, including documentation and tools for troubleshooting and resolving technical issues with Cisco products and technologies.

To receive security and technical information about your products, you can subscribe to various services, such as the Product Alert Tool (accessed from Field Notices), the Cisco Technical Services Newsletter, and Really Simple Syndication (RSS) Feeds.

Access to most tools on the Cisco Support website requires a Cisco.com user ID and password.

http:/​/​www.cisco.com/​cisco/​web/​support/​index.html

Feature Information for Per VRF for TACACS Servers

The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/​go/​cfn. An account on Cisco.com is not required.

Table 1 Feature Information for Per VRF for TACACS+ Servers

Feature Name

Releases

Feature Information

Per VRF for TACACS+ Servers

Cisco IOS XE Release 2.2

The Per VRF for TACACS+ Servers feature allows per virtual route forwarding (per VRF) to be configured for authentication, authorization, and accounting (AAA) on TACACS+ servers.

In Cisco IOS XE Release 2.2, this feature was introduced on the Cisco ASR 1000 Series Aggregation Services Routers.

The following commands were introduced or modified: ip tacacs source-interface, ip vrf forwarding (server-group), server-private (TACACS+).