Attribute Screening for Access Requests

The Attribute Screening for Access Requests feature allows you to configure your network access server (NAS) to filter attributes in outbound Access Requests to the RADIUS server for purposes of authentication or authorization.

Finding Feature Information

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Prerequisites for Attribute Screening for Access Requests

  • You must be familiar with configuring attribute lists.

Restrictions for Attribute Screening for Access Requests

  • Attributes 1 (Username), 2 (User-Password), and 3 (Chap-Password) cannot be filtered.

Information About Attribute Screening for Access Requests

Configuring an NAS to Filter Attributes in Outbound Access Requests

The Attribute Screening for Access Requests feature allows you to configure your NAS to filter attributes in outbound Access Requests to the RADIUS server for purposes of authentication or authorization. The filters can be configured on the NAS, or they can be downloaded via downloadable vendor-specific attributes (VSAs) from the authentication, authorization, and accounting (AAA) server.

The following are some examples of the downloadable VSAs:

Cisco:Cisco-Avpair=“ppp-authen-type=chap”
Cisco:Cisco-Avpair=“ppp-authen-list=group 1”
Cisco:Cisco-Avpair=“ppp-author-list=group 1”
Cisco:Cisco-Avpair=“vpdn:tunnel-id=B53”
Cisco:Cisco-Avpair=“vpdn:ip-addresses=10.0.58.35”

Note

You must be aware of which attributes you want to filter. Filtering certain key attributes can result in authentication failure (for example, attribute 60 should not be filtered).

How to Configure Attribute Screening for Access Requests

Configuring Attribute Screening for Access Requests

or

accounting [request | reply] [accept | reject] listname

SUMMARY STEPS

    1.    enable

    2.    configure terminal

    3.    radius-server attribute list listname

    4.    attribute value1 [value2[value3 ...]]

    5.    aaa group server radius group-name

    6.    Do one of the following:

    • authorization [request | reply][accept | reject] listname
    • accounting [request | reply] [accept | reject] listname


DETAILED STEPS
     Command or ActionPurpose
    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 radius-server attribute list listname


    Example:
    Router (config)# radius-server attribute list attrlist
     

    Defines an attribute list.

     
    Step 4 attribute value1 [value2[value3 ...]]


    Example:
    Router (config)# attribute 6-10, 12
     

    Adds attributes to an accept or reject list.

     
    Step 5 aaa group server radius group-name


    Example:
    Router (config)# aaa group server radius rad1
     

    Applies the attribute list to the AAA server group and enters server-group configuration mode.

     
    Step 6Do one of the following:
    • authorization [request | reply][accept | reject] listname
    • accounting [request | reply] [accept | reject] listname


    Example:
    Router (config-sg-radius)# authorization request accept attrlist


    Example:
    

        
    
 

    Example:
    
          
              
    

        
    
 

    Example:
    
          
    Router (config-sg-radius)# accounting request accept attrlist
    

        
    
 
          		 
          
    
Filters attributes in outbound Access Requests to the RADIUS server for purposes of authentication or authorization.
    

          
    • 
The request keyword defines filters for outgoing authorization Access Requests.
      

      • 

    • 
The reply keyword defines filters for incoming authorization Accept and Reject packets and for outgoing accounting requests.
      

      • 

    

         
      
    

    

    

    

    Configuring a Router to Support Downloadable Filters
    

    
      
    
To configure your router to support downloadable filters, perform the following steps.
    

    
    
SUMMARY STEPS
      1.   
      
          
            enable
          
        
      

      2.   
      
          
            configure
          
          
            terminal
          
        
      

      3.   
      
          
            aaa
            authorization
            template
          
        
      

      4.   
      
          
            aaa
            authorization
            network
            default
            group
            radius
          
        
      

      5.   
      
          
            radius-server
            attribute
            list
          
          
            list-name
          
        
      

      6.   
      
          
            attribute
          
          
            
            
          
          
            value1
           [value2 [value3...]]
      


    DETAILED STEPS
       Command or ActionPurpose
      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
            authorization
            template
          
        
       

      Example:
      
          
      Router (config)# aaa authorization template
      

        
      
 
            		 
          
      
Enables usage of a local or remote customer template on the basis of Virtual Private Network (VPN) routing and forwarding (VRF).
      

         
      
      

      Step 4
          
            aaa
            authorization
            network
            default
            group
            radius
          
        
       

      Example:
      
          
      Router (config)# aaa authorization network default group radius
      

        
      
 
            		 
          
      
Sets parameters that restrict user access to a network.
      

         
      
      

      Step 5
          
            radius-server
            attribute
            list
          
          
            list-name
          
        
       

      Example:
      
          
      Router (config)# radius-server attribute list attlist
      

        
      
 
            		 
          
      
Defines an accept or reject list name.
      

         
      
      

      Step 6
          
            attribute
          
          
            
            
          
          
            value1
           [value2 [value3...]]
       

      Example:
      
          
      Router (config)# attribute 10-14, 24
      

        
      
 
            		 
          
      
Adds attributes to an accept or reject list.
      

         
      
      

      

      

      Troubleshooting Tips
      

      
If attribute filtering is not working, ensure that the attribute list is properly defined.
      

      

      

      

      Monitoring and Maintaining Attribute Filtering for Access Requests
      

      
      
      
To monitor and maintain attribute filtering, you can use the debug radiuscommand.
      

    
      
SUMMARY STEPS
        1.   
      
          
            enable
          
        
        

        2.   
      
          
            debug
            radius
          
        
        


      DETAILED STEPS
         Command or ActionPurpose
        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, including filtering information.
        

         
      
        

        

        

        

        

        Configuration Examples for Attribute Filtering for Access Requests
        

        
    
        

        

        Attribute Filtering for Access Requests  Example
        

        
      
        
The following example shows that the attributes 30-31 that are defined in “all-attr” will be rejected in all outbound Access Request messages:
        

      
        aaa group server radius ras
 server 172.19.192.238 auth-port 1745 acct-port 1746
 authorization request reject all-attr
!
.
.
.
radius-server attribute list all-attr
 attribute 30-31
!
.
.
.
        

    
        

        

        

        Attribute Filtering User Profile  Example
        

        
      
        
The following is a sample user profile after attribute filtering has been configured for Access Requests:
        

      
        cisco.com Password = "cisco"
Service-Type = Framed,
Framed-Protocol = PPP,
Cisco:Cisco-Avpair = :1:"rad-serv=172.19.192.87 key rad123",
Cisco:Cisco-Avpair = :1:"rad-serv-filter=authorization request reject range1",
Cisco:Cisco-Avpair = :1:"rad-serv-filter=accounting request reject range1",
Cisco:Cisco-Avpair = "ppp-authen-type=chap"
Cisco:Cisco-Avpair = "ppp-authen-list=group 1",
Cisco:Cisco-Avpair = "ppp-author-list=group 1",
Cisco:Cisco-Avpair = "ppp-acct-list=start-stop group 1",
Cisco:Cisco-Avpair = "vpdn:tunnel-id=B53",
Cisco:Cisco-Avpair = "vpdn:tunnel-type=l2tp",
Cisco:Cisco-Avpair = "vpdn:ip-addresses=10.0.58.35",
Cisco:Cisco-Avpair = "vpdn:l2tp-tunnel-password=cisco"
user2@cisco.com
Service-Type = Outbound,
Cisco:Cisco-Avpair = "vpdn:tunnel-id=B53",
Cisco:Cisco-Avpair = "vpdn:tunnel-type=l2tp",
Cisco:Cisco-Avpair = "vpdn:ip-addresses=10.0.58.35",
Cisco:Cisco-Avpair = "vpdn:l2tp-tunnel-password=cisco"

        

      
        
When a session for user2@cisco.com “comes up” at the Layer 2 Tunneling Protocol (L2TP) Network Server (LNS)--as is shown above--because the aaa authorization template command has been configured, a RADIUS request is sent to the server for Cisco.com. The server then sends an Access Accept message if authentication is successful, along with the VSAs that are configured as part of the Cisco.com profile. If filters are configured as part of the Cisco.com profile, these filters will be parsed and applied to the RADIUS requests for user2@cisco.com.
        

      
        
In the above profile example, filter range1 has been applied to the authorization and accounting requests.
        

    
        

        

        

        debug radius Command  Example
        

        
      
        
If the attribute you are trying to filter is rejected, you will see an debug radius output statement similar to the following:
        

      
        RADIUS: attribute 31 rejected

        

      
        
If you try to filter an attribute that cannot be filtered, you will see an output statement similar to the following:
        

      
        RADIUS: attribute 1 cannot be rejected
        

    
        

        

        

        

        Additional References
        

         
	 
        

        Related Documents
         
		 
		

         
					 
         Related Topic
					 
        
 
				          		
 
					 
         Document Title
					 
        
 
				          		

        
        

         
					 
         Cisco IOS commands
					 
        
 
				          		
 
					 
         
						Cisco IOS Master Commands List, All Releases 
					 
        
 
				          		

        

         
					 
         Configuring RADIUS
					 
        
 
				          		
 
					 
         Configuring RADIUS feature module. 
					 
        
 
				          		

        

         
					 
         Security commands
					 
        
 
				          		
 
					 
         
						Cisco IOS Security Command Reference 
					 
        
 
				          		

        
        

        

        
 
	 
        

        Standards
         
		 
		

         
					 
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         None.
					 
        
 
				          		
 
					 
         --
					 
        
 
				          		

        
        

        

        
 
	 
        

        MIBs
         
		 
		

         
					 
         MIBs
					 
        
 
				          		
 
					 
         MIBs Link
					 
        
 
				          		

        
        

         
					 
         None
					 
        
 
				          		
 
					 
         To locate and download MIBs for selected platforms, Cisco software releases, and feature sets, use Cisco MIB Locator found at the following URL:
					 
        
 
					 
         
						http:/​/​www.cisco.com/​go/​mibs 
					 
        
 
				          		

        
        

        

        
 
	 
        

        RFCs
         
		 
		

         
					 
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        Technical Assistance
         
		 
		

         
					 
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         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 Attribute Screening for Access Requests
        

        
			
        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 Attribute Screening for Access Requests 
         
				  
         Feature Name
				  
        
 
				        		
 
				  
         Releases
				  
        
 
				        		
 
				  
         Feature Information
				  
        
 
				        		

        
        

         
				  
         Attribute Screening for Access Requests
				  
        
 
				        		
 
				  
         Cisco IOS XE Release 2.1
				  
        

        Cisco IOS XE Release 3.3S
        
 
				        		
 
				  
         This feature was introduced on the Cisco ASR 1000 Series Aggregation Services Routers.
				  
        
 
				  
         The Attribute Screening for Access Requests feature allows a network access server (NAS) to be configured to filter attributes in outbound Access Requests to the RADIUS server for purposes of authentication or authorization.
				  
        
 
				  
         The following commands were introduced or modified by this feature: 
					 authorization 
						(server-group).