RADIUS Attribute 104

The RADIUS Attribute 104 feature allows private routes (attribute 104) to be specified in a RADIUS authorization profile. The private routes affect only packets that are received on an individual interface. The routes are stored apart from the global routing table and are not injected into any routing protocols for redistribution.

Prerequisites for RADIUS Attribute 104

  • You must be using a Cisco RADIUS server.

  • You should be familiar with configuring RADIUS.

  • You should be familiar with policy-based routing (PBR) and private routes.

  • You should be familiar with configuring access control lists (ACLs).

  • Before using the RADIUS Attribute 104 feature, you must configure RADIUS AAA authorization and RADIUS route download.

  • The following memory bytes are requireF:\tips-migration
    • One route map--50 bytes.
    • One match-set clause--600 bytes.
    • One extended ACL--366 bytes.
    • For N number of attribute 104s, the memory requirement is (600+366)*N+50=1000*N(approximate) per user.

Restrictions for RADIUS Attribute 104

  • If you already have PBR locally (statically) configured under the interface, and you specify attribute 104, the locally configured PBR will be disabled.

  • If a pseudo next-hop address is involved, there must be a route available in the routing table for the next-hop address. If a route is not available, the packet will not be policy routed.

  • Policy routing does not order the match-set clauses and relies on the first match, so you should specify the attributes in the order in which you want them to be matched.

  • Metric numbers cannot be used in the attribute.

Information About RADIUS Attribute 104

Policy-Based Routing Background

PBR provides a mechanism for the forwarding, or routing of, data packets on the basis of defined policies. The policies are not wholly dependent on the destination address but rather on other factors, such as type of service, source address, precedence, port numbers, or protocol type.

Policy-based routing is applied to incoming packets. All packets that are received on an interface that has policy-based routing enabled are considered for policy-based routing. The router passes the packets through enhanced packet filters called route maps. On the basis of the criteria that are defined in the route maps, the packets are forwarded to the appropriate next hop.

Each entry in a route map statement contains a combination of match clauses and set clauses or commands. The match clauses define the criteria for whether appropriate packets meet the particular policy (that is, whether the conditions are met). The set clauses provide instruction for how the packets should be routed after they have met the match criteria. The match clause specifies which set of filters a packet must match for the corresponding set clause to be applied.

Attribute 104 and the Policy-Based Route Map

This section discusses the attribute 104 feature and how it works with policy-based route maps.

RADIUS Attribute 104 Overview

Using the RADIUS Attribute 104 feature, you can specify private routes in your RADIUS authorization profile. The private routes you specify will affect only packets that are received on an individual interface. The routes are stored apart from the global routing table and are not injected into any routing protocols for redistribution.

Permit Route Map

Route map statements can be marked as “permit” or “deny.” If the statement is marked “permit,” the set clause is applied to the packets that match the match criteria. For attribute 104, when you are configuring the route map, you need to mark the route map as “permit,” as follows. See Related Documentsfor where to find information on configuring a route map.

Default Private Route

The policy routing process proceeds through the route map until a match is found. If no match is found in the route map, the global routing table is consulted. If you have specified a default route in your user profile, any further routes beyond the default route are effectively ignored.

Route Map Order

You need to specify route maps on the server in the order that you want them to be applied.

How to Apply RADIUS Attribute 104

Applying RADIUS Attribute 104 to Your User Profile

You can apply RADIUS attribute 104 to your user profile by adding the following to the RADIUS server database.

SUMMARY STEPS

  1. Apply RADIUS attribute 104 to your user profile.

DETAILED STEPS

Command or Action Purpose

Apply RADIUS attribute 104 to your user profile. 


Ascend-Private-Route=”dest_addr/netmask next_hop”
The destination network address of the router is “dest_addr/netmask”, and the address of the next-hop router is “next_hop.”

Examples

The following is a sample user profile that creates three private routes that are associated with the caller: 


username Password="ascend"; User-Service=Framed-User
   Framed-Protocol=PPP,
   Framed-Address=10.1.1.1,
   Framed-Netmask=255.0.0.0,
   Ascend-Private-Route="172.16.1.1/16 10.10.10.1"
   Ascend-Private-Route="192.168.1.1/32 10.10.10.2"
   Ascend-Private-Route="10.20.0.0/1 10.10.10.3"
   Ascend-Private-Route="10.0.0.0/0 10.10.10.4"

Using the above profile, the private routing table for the connection contains the following routes, including a default route: 


Destination/Mask     Gateway
172.16.1.1/16         10.10.10.1
192.168.1.1/32         10.10.10.2
10.20.20.20/1       10.10.10.3
10.0.0.0/0            10.10.10.4

Verifying Route Maps

You can use the following show commands to verify the route maps that have been configured.

SUMMARY STEPS

  1. enable
  2. show ip policy
  3. show route-map [map-name | dynamic [dynamic-map-name | application [application-name ]] | all ]

DETAILED STEPS

  Command or Action Purpose

Step 1

enable

Example:


Router> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

show ip policy

Example:


Router# show ip policy

Displays the route map that is used for policy routing.

Step 3

show route-map [map-name | dynamic [dynamic-map-name | application [application-name ]] | all ]

Example:


Router# show route-map

Displays all route maps that are configured or only the one that is specified.

Troubleshooting the RADIUS Profile

If your private route configuration is not working properly, you may want to reread the section “ Policy-Based Routing Background.” This section may help you determine what is happening to the packets. In addition, the following debug commands can be used to troubleshoot your RADIUS profile.

SUMMARY STEPS

  1. enable
  2. debug radius
  3. debug aaa per-user
  4. debug ip policy

DETAILED STEPS

  Command or Action Purpose

Step 1

enable

Example:


Router> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

debug radius

Example:


Router# debug radius

Displays information associated with RADIUS.

Step 3

debug aaa per-user

Example:


Router# debug aaa per-user

Displays the attributes that are applied to each user as the user authenticates.

Step 4

debug ip policy

Example:


Router# debug ip policy

Displays IP routing packet activity.

Configuration Examples for RADIUS Attribute 104

Route-Map Configuration in Which Attribute 104 Has Been Applied Example

The following output is a typical route-map configuration to which attribute 104 has been applieF:\tips-migration 


Router# show route-map dynamic
route-map AAA-01/08/04-14:13:59.542-1-AppSpec, permit, sequence 0, identifier 1639994476
  Match clauses:
    ip address (access-lists): PBR#1 PBR#2
  Set clauses:
  Policy routing matches: 0 packets, 0 bytes
route-map AAA-01/08/04-14:13:59.542-1-AppSpec, permit, sequence 1, identifier 1640264784
  Match clauses:
    ip address (access-lists): PBR#3 PBR#4
  Set clauses:
  Policy routing matches: 0 packets, 0 bytes
route-map AAA-01/08/04-14:13:59.542-1-AppSpec, permit, sequence 2, identifier 1645563704
  Match clauses:
    ip address (access-lists): PBR#5 PBR#6
    length 10 100
  Set clauses:
    ip next-hop 10.1.1.1
    ip gateway10.1.1.1
  Policy routing matches: 0 packets, 0 bytes
 Current active dynamic routemaps = 1

Additional References

The following sections provide references related to RADIUS NAS-IP-Address Attribute Configurability.

Related Documents

Related Topic

Document Title

Configuring AAA

“Authentication, Authorization, and Accounting (AAA)” section of Cisco IOS Security Configuration Guide: Securing User Services

Configuring RADIUS

“ Configuring RADIUS ” module.

RADIUS commands

Cisco IOS Security Command Reference

Standards

Standards

Title

None

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MIBs

MIBs

MIBs Link

None

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

RFCs

Title

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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.

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Feature Information for RADIUS Attribute 104

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 RADIUS Attribute 104

Feature Name

Releases

Feature Information

RADIUS Attribute 104

Cisco IOS XE Release 3.9S

The RADIUS Attribute 104 feature allows private routes (attribute 104) to be specified in a RADIUS authorization profile. The private routes affect only packets that are received on an individual interface. The routes are stored apart from the global routing table and are not injected into any routing protocols for redistribution.

The following commands were introduced or modifieF:\tips-migration show ip policy , show route-map .