Cisco IOS XE Intelligent Services Gateway Configuration Guide, Release 2 - Enabling ISG to Interact with External Policy Servers [Cisco IOS XE Software]

Table Of Contents

Enabling ISG to Interact with External Policy Servers

Finding Feature Information

Contents

Prerequisites for ISG Interaction with External Policy Servers

Restrictions for ISG Interaction with External Policy Servers

Information About ISG Interaction with External Policy Servers

Initial and Dynamic Authorization

How to Enable ISG to Interact with External Policy Servers

Configuring the ISG as a AAA Client

Prerequisites

Configuring the ISG as a AAA Server

Configuration Examples for ISG Interaction with External Policy Servers

ISG Interaction with External Policy Servers: Example

Additional References

Related Documents

Standards

MIBs

RFCs

Technical Assistance

Feature Information for ISG Interaction with External Policy Servers

Enabling ISG to Interact with External Policy Servers

First Published: March 20, 2006

Last Updated: June 19, 2009

Intelligent Services Gateway (ISG) is a Cisco IOS and Cisco IOS XE software feature set that provides a structured framework in which edge devices can deliver flexible and scalable services to subscribers. This document describes how to enable ISG to retrieve session policies or accept dynamic updates to session policies from external policy servers.

Finding Feature Information

For the latest feature information and caveats, see 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 for ISG Interaction with External Policy Servers" section.

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

Contents

•Prerequisites for ISG Interaction with External Policy Servers

•Restrictions for ISG Interaction with External Policy Servers

•Information About ISG Interaction with External Policy Servers

•How to Enable ISG to Interact with External Policy Servers

•Configuration Examples for ISG Interaction with External Policy Servers

•Additional References

•Feature Information for ISG Interaction with External Policy Servers

Prerequisites for ISG Interaction with External Policy Servers

For information about release and platform support, see the "Feature Information for ISG Interaction with External Policy Servers" section.

Restrictions for ISG Interaction with External Policy Servers

The ISG and external policy servers should be in the same virtual routing and forwarding instance (VRF).

Information About ISG Interaction with External Policy Servers

To configure ISG interaction with external policy servers, you should understand the following concept:

•Initial and Dynamic Authorization

Initial and Dynamic Authorization

ISG works with external devices, referred to as policy servers, that store per-subscriber and per-service information. ISG supports two models of interaction between ISG and external policy servers: initial authorization and dynamic authorization.

In the initial authorization model, ISG must retrieve policies from the external policy server at specific points in a session. In this model, the external policy server is typically an authentication, authorization, and accounting (AAA) server that uses RADIUS. ISG is the RADIUS client. Instead of a AAA server, some systems use a RADIUS proxy component that converts to other database protocols such as Lightweight Directory Access Protocol (LDAP).

The dynamic authorization model allows the external policy server to dynamically send policies to the ISG. These operations can be initiated in-band by subscribers (through service selection) or through the actions of an administrator, or applications can change policies on the basis of some algorithm (for example, change session quality of service (QoS) at a certain time of day). This model is facilitated by the Change of Authorization (CoA) RADIUS extension. CoA introduced peer-to-peer capability to RADIUS, enabling ISG and the external policy server each to act as a RADIUS client and server.

How to Enable ISG to Interact with External Policy Servers

This section contains the following tasks:

•Configuring the ISG as a AAA Client

•Configuring the ISG as a AAA Server

Configuring the ISG as a AAA Client

Perform this task to configure AAA method lists and enable ISG to retrieve policies from a AAA server. This task must be performed for both initial and dynamic authorization models.

Prerequisites

The servers and server groups referenced by the AAA methods must be configured.

SUMMARY STEPS

1. enable

2. configure terminal

3. aaa authentication login {default | list-name} method1 [method2...]

4. aaa authentication ppp {default | list-name} method1 [method2...]

5. aaa authorization {network | exec | commands level | reverse-access | configuration} {default | list-name} [method1 [method2...]]

6. aaa authorization subscriber-service {default | list-name} method1 [method2...]

7. aaa accounting {auth-proxy | system | network | exec | connection | commands level} {default | list-name} [vrf vrf-name] {start-stop | stop-only | none} [broadcast] group groupname

8. end

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

aaa authentication login {default | list-name} method1 [method2...]
Example:

Router(config)# aaa authentication login PPP1 group radius

Specifies one or more AAA authentication methods to be used at login.

Step 4

aaa authentication ppp {default | list-name} method1 [method2...]
Example:

Router(config)# aaa authentication ppp default group radius

Specifies one or more AAA authentication methods for use on serial interfaces that are running PPP.

Step 5

aaa authorization {network | exec | commands level | reverse-access | configuration} {default | list-name} [method1 [method2...]]
Example:

Router(config)# aaa authorization network NET1 radius

Specifies one or more AAA authorization methods to be used for restricting subscriber access to a network.

Step 6

aaa authorization subscriber-service {default | list-name} method1 [method2...]
Example:

Router(config)# aaa authorization subscriber-service default radius

Specifies one or more AAA authorization methods for ISG to use in providing a service.

Step 7

aaa accounting {auth-proxy | system | network | exec | connection | commands level} {default | list-name} [vrf vrf-name] {start-stop | stop-only | none} [broadcast] group groupname
Example:

Router(config)# aaa accounting network default start-stop group radius

Enables AAA accounting of requested services for billing or security purposes.

Step 8

end
Example:

Router(config)# end

Exits global configuration mode.

Configuring the ISG as a AAA Server

Dynamic authorization allows a policy server to dynamically send policies to ISG. Perform this task to configure the ISG as a AAA server and enable dynamic authorization.

SUMMARY STEPS

1. enable

2. configure terminal

3. aaa server radius dynamic-author

4. client {name | ip-address} [key [0 | 7] word] [vrf vrf-id]

5. port port-number

6. server-key [0 | 7] word

7. auth-type {all | any | session-key}

8. ignore {server-key | session-key}

9. end

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

aaa server radius dynamic-author
Example:

Router(config)# aaa server radius dynamic-author

Configures the ISG as a AAA server.

Step 4

client {name | ip-address} [key [0 | 7] word] [vrf vrf-id]
Example:

Router(config-locsvr-da-radius)#

Specifies a client with which ISG will be communicating.

Step 5

port port-number
Example:

Router(config-locsvr-da-radius)# port 1600

Specifies the RADIUS server port.

•Default is 1700.

Step 6

server-key [0 | 7] word
Example:

Router(config-locsvr-da-radius)# server-key cisco

Specifies the encryption key shared with the RADIUS client.

Step 7

auth-type {all | any | session-key}
Example:

Router(config-locsvr-da-radius)# auth-type all

Specifies the attributes to be used for session authorization.

Step 8

ignore {server-key | session-key}
Example:

Router(config-locsvr-da-radius)# ignore session-key

Configures ISG to ignore the shared encryption key or attribute 151.

Step 9

end
Example:

Router(config)# end

Exits global configuration mode.

Configuration Examples for ISG Interaction with External Policy Servers

This section contains the following example:

•ISG Interaction with External Policy Servers: Example

ISG Interaction with External Policy Servers: Example

The following example configures ISG to interact with external policy servers:
!
aaa group server radius CAR_SERVER
 server 10.100.2.36 auth-port 1812 acct-port 1813
!
aaa authentication login default none
aaa authentication login IP_AUTHEN_LIST group CAR_SERVER
aaa authentication ppp default group CAR_SERVER
aaa authorization network default group CAR_SERVER 
aaa authorization subscriber-service default local group radius 
aaa accounting network default start-stop group CAR_SERVER
!
aaa server radius dynamic-author
 client 10.76.86.90 key cisco
 client 172.19.192.25 vrf VRF1 key cisco
 client 172.19.192.25 vrf VRF2 key cisco
 client 172.19.192.25 key cisco
message-authenticator ignore

Additional References

The following sections provide references related to ISG interaction with external policy servers.

Related Documents

Related Topic

Document Title

ISG commands

Cisco IOS Intelligent Services Gateway Command Reference

AAA configuration tasks

"Authentication, Authorization, and Accounting (AAA)" section of the Cisco IOS XE Security Configuration Guide

AAA commands

Cisco IOS Security Command Reference

Standards

Standard

Title

No new or modified standards are supported by this feature.

—

MIBs

MIB

MIBs Link

No new or modified MIBs are supported by this feature.

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

http://www.cisco.com/go/mibs

RFCs

RFC

Title

None

—

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/techsupport

Feature Information for ISG Interaction with External Policy Servers

Table 1 lists the features in this module and provides links to specific configuration information. For information about a feature in this technology that is not documented here, see the "Intelligent Services Gateway Features Roadmap."

Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which Cisco IOS XE software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.

Note Table 1 lists only the Cisco IOS XE software release that introduced support for a given feature in a given Cisco IOS XE software release train. Unless noted otherwise, subsequent releases of that Cisco IOS XE software release train also support that feature.

Table 1 Feature Information for ISG Interaction with External Policy Servers

Feature Name

Releases

Feature Information

ISG: Policy Control: Policy Server: CoA

Cisco IOS XE Release 2.2

Cisco IOS XE Release 2.4

This feature provides ISG support for the RADIUS Change of Authorization (CoA) extension, which facilitates dynamic authorization.

The following sections provide information about this feature:

•Initial and Dynamic Authorization

•How to Enable ISG to Interact with External Policy Servers

This feature was integrated into Cisco IOS XE Release 2.4.

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