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User Guide for Cisco Access Registrar 4.2
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Preface
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Overview
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Using the aregcmd Commands
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Using the Graphical User Interface
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Access Registrar Server Objects
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Using the radclient Command
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Configuring Local Authentication and Authorization
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RADIUS Accounting
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Extensible Authentication Protocols
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Using WiMAX in Cisco Access Registrar
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Using Extension Points
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Using Replication
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Using On-Demand Address Pools
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Using Identity Caching
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Using Trusted ID Authorization with SESM
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Using Prepaid Billing
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Using Cisco Access Registrar Server Features
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Directing RADIUS Requests
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Wireless Support
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Using LDAP
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Using Open Database Connectivity
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Using SNMP
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Enforcement of TPS License
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Backing Up the Database
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Using the REX Accounting Script
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Logging Syslog Messages
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Troubleshooting Cisco Access Registrar
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Appendix A: Cisco Access Registrar Tcl and REX Dictionaries
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Appendix B: Environment Dictionary
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Appendix C: RADIUS Attributes
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Glossary
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Index
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Table Of Contents
Using Cisco Access Registrar Server Features
Configurable Worker Threads Enhancement
Support for Windows Provisioning Service
Account Expiration and Renewal
Password Changing and Force Update
Configuration Example - AccountingGroupService
Configuration Example 2 - AuthenticationGroupService
SHA-1 Support for LDAP-Based Authentication
Remote LDAP Server Password Encryption
Object Properties with Dynamic Support
xDSL VPI/VCI Support for Cisco 6400
Using User-Name/User-Password for Each Cisco 6400 Device
Format of the New User-Name Attribute
Apply Profile in Cisco Access Registrar Database to Directory Users
Example User-Profile and User-Group Attributes in Directory User Record
Directory Multi-Value Attributes Support
Automatic Information Collection (arbug)
Simultaneous Terminals for Remote Demonstration
Support for RADIUS Check Item Attributes
Configuring Usergroup Check Items
Configuring Packet of Disconnect
Configuring a Resource Manager for POD
Proxying POD Requests from External Servers
Configuring Change of Authorization Requests
Testing Dynamic DNS with radclient
Dynamic Service Authorization Feature
Configuring Dynamic Service Authorization Feature
Setting up the Environment Variable
Using Cisco Access Registrar Server Features
Revised: March 20, 2009, OL-17222-03
This chapter provides information about how to use the following Cisco Access Registrar (CAR) server features:
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"Incoming Traffic Throttling" section
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Incoming Traffic Throttling
CAR offers two options to tackle traffic bursts by limiting incoming traffic. You will find two new properties, MaximumIncomingRequestRate and MaximumOutstandingRequests, under /Radius/Advanced to limit the incoming traffic.
MaximumIncomingRequestRate
You can use the MaximumIncomingRequestRate property to limit incoming traffic in terms of "allowed requests per second".
For example, if you set the MaximumIncomingRequestRate to n, then at any given second, only n requests are accepted for processing. In the next second, another n requests are accepted regardless of whether the requests accepted earlier are processed or not. This condition serves as a soft limit.
The MaximumIncomingRequestRate property by default is zero (disabled).
MaximumOutstandingRequests
You can use the MaximumOutstandingRequests property to limit incoming traffic in terms of "requests processed".
For example, if you set the MaximumOutstandingRequests to n, n requests are accepted for processing. Further requests are accepted only after processing some of these requests and sending the replies back. This condition serves as a hard limit.
The MaximumOutstandingRequests property by default is zero (disabled).
Note
You must follow the steps outlined below to configure the MaximumIncomingRequestRate or MaximumOutstandingRequests property:
Step 1
Step 2
Step 3
set MaximumIncomingRequestRate n
or
set MaximumOutstandingRequests n
where n is any nonzero value.
Step 4
save
Step 5
reload
Backing Store Parsing Tool
CAR tool, carbs.pl, helps to analyze the session backing store files. You will find this tool under /cisco-ar/bin directory.
Using carbs.pl, you can:
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The syntax is:
carbs.pl [-a] [-d <dir>] [-f <logfile>] [-v] [p] [-o <output>] [-h]
-a—All session statistics (active, stale, stopped)
-d—<Directory> Default: .
-f—<Filename> Default: 00*.log
-v—verbose Default: off
-p—Clear phantom sessions
-o—<Filename> Output log to TEXT
-h—Help, usage
Table 16-1 lists the options available with carbs.pl and their description.
Configurable Worker Threads Enhancement
CAR provides a configurable variable you can use to increase the number of worker threads to handle a greater number of RADIUS packets during peak operating periods. This variable controls the processing of greater number of RADIUS packets than expected during peak operating periods.
The variable, RADIUS_WORKER_THREAD_COUNT, is found in the arserver file under /cisco-ar/bin/arserver and controls the number of worker threads the CAR server creates. You can increase the number of worker threads to help make more efficient use of the server's CPU.
Note
Increasing the number of worker threads also increases memory utilization.The default value of RADIUS_WORKER_THREAD_COUNT for servers running a Solaris operating system is 256. The default value for servers running Red Hat Enterprise Linux (RHEL) is 64.
The purpose of this enhancement is to take advantage of spare CPU bandwidth which was not being used in earlier releases of CAR due to a lower number of worker threads. At times, the worker threads would be stuck doing work that took a long time to complete, like running a script. Having more threads will help mitigate these situations and will help improve on the latency created due to lack of free worker threads.
Note
To modify the RADIUS_WORKER_THREAD_COUNT variable:
Step 1
Step 2
Step 3
#change this to configure number of worker threadsRADIUS_WORKER_THREAD_COUNT=256Step 4
Note
Step 5
Session-Key Lookup
The Session-Key Lookup feature enables you to identify the Session Manager and Session Key of an existing session based on certain attributes associated with that session, such as the Mobile Station Integrated Services Digital Network (MSISDN) number.
The Session-Key Lookup feature required the following enhancements to CAR software:
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The Session-Key Lookup feature is useful in a scenario where an existing session requires an update from an incoming Ascend-IPA-Allocate packet (from a different NAS or device) with modified authorization attributes. Note that this Ascend-IPA-Packet might not have the exact set of attributes as the original packet that created the session. However, the Ascend-IPA-Allocate packet must contain at least one attribute that can uniquely identify the session (such as the MSISDN number) and should contain the same UserName of the original session.
The Session-Key Lookup feature works in tandem with the Radius Query feature, where a Radius Query service is defined with the unique attribute (such as the MSISDN number) as the query-key and is configured to query all session managers. The Query-Service environment variable is set to the defined Radius Query service and the new environment variable (Set-Session-Mgr-And-Key-Upon-Lookup) is set to TRUE for this Ascend-IPA-Allocate packet. This triggers a query operation on all the live sessions. If there is a match, the Session-Manager and Session-Key of that session is used for subsequent session management. During session management, the session cache is updated with the modified authorization attributes.
The Session-Manager OutgoingScript (or any outgoing script that executes after the Session-Manager Outgoing Script) should not reject the packet when doing a Session-Key lookup. Doing so causes the session to be deleted.
Query-Notify
The Query-Notify feature enables you to store information about Wireless Application Protocol (WAP) gateways that have queried for User Identity-IP Address mapping and send appropriate messages to the WAP gateway when the subscriber logs out of the network.
CAR has been enhanced to update the session cache with the attribute-value pairs of an interim accounting update packet. This ensures that CAR server provides the most up-to-date information to the WAP gateway during the proxy of interim records or query of the session cache.
CAR has been enhanced to also notify the WAP gateways that have queried a session with Interim accounting update packets. If a WAP gateway does not respond to the Interim accounting update packets, the CAR server times out and retries by notifying the WAP gateways again. If there is no response after all the retries, the proxy packet is deleted and no change is made to the session or the WAP gateway's state in the CAR server. You can configure the number of retries under /Radius/Clients/notificationproperties.
The accounting response packet from the CAR server to the GPRS Gateway Support Node (GGSN) is independent of the proxy operation to the WAP gateways. The accounting response packet is sent back immediately without waiting for responses from the WAP gateways.
The Query-Notify feature also enables you to quarantine IP addresses for a configurable amount of time if a WAP gateway does not respond to Accounting-Stop packets sent by the CAR server.
The CAR server stores information about clients (usually the IP address) that queried for particular user information and send RADIUS Accounting-Stop packets to those clients when the CAR server receives the Accounting-Stop packet. There is no intermediate proxy server between the CAR server and the WAP gateway.
To support the Query-Notify feature, the CAR server's radius-query service has been modified to also store information like the IP address about the clients queried for cached information. The information is stored in the user session record along with the cached information so it is available after a server reload.
To use the Query-Notify feature, you must make the following configuration changes:
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The EnableNotifications property indicates that a client can receive Accounting-Stop notifications from the CAR server. When EnableNotifications is set to TRUE, a sub-directory named NotificationProperties appears in client object configuration.
Step 3
See Clients, page 4-5, for information about how to configure these properties.
Step 4
Call Flow
This section describes the call flow of the Query-Notify feature.
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This information is usually from a GGSN when a subscriber enters into the network.
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The CAR server sends an Access-Accept packet to the WAP gateway. The list of attributes sent in this Access-Accept will depends on radius-query service configuration.
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If the WAP gateway queried clients do not respond to the Accounting-Interim-Update packets, the CAR server times out and retries by notifying the WAP gateways again. If there is no response after all the retries, the proxy packet is deleted and no change is made to the session or the WAP gateway's state in the CAR server. The StaleSessionTimeout property under /Radius/Advanced is not applicable for Accounting-Interim-Update packets.
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Before releasing the subscriber's session, the CAR server looks for any client IP addresses in the subscriber's cache. If it finds any, the CAR server sends Accounting-Stop packets to those clients with the attributes configured in the NotificationAttributeGroup subdirectory for each client.
The CAR server forms the attributes with those attributes in the session cache and from the Accounting-Stop packet. The CAR server uses the value configured for the Port property in the NotificationProperties subdirectory as the destination port for the Accounting-Stop packet and uses the client's shared secret.
The CAR server then waits for Accounting-Response packets from each client to which it has sent Accounting-Stop packets. The CAR server waits for the time interval configured in the InitialTimeout property configured in the NotificationProperties subdirectory before sending another Accounting-Stop packet. If it does not receive an Accounting-Response packet, the CAR server sends additional Accounting-Stop packets until the number of attempts reaches the value configured in the MaxTries property in the NotificationProperties subdirectory.
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If the CAR server does not receive Accounting-Response packets from all clients after the configured time and attempts, the server maintains the subscriber session for the time interval configured in the StaleSessionTimeout property in /Radius/Advanced then releases the subscriber session.
The CAR server maintains the subscriber session to address the quarantine IP address requirement. The CAR server must quarantine IP addresses if a WAP gateway does not respond to Accounting-Stop sent by the CAR server. The length of time an IP address is quarantined depends on the value of the InitialTimeOut property under the NotificationProperties subdirectory of /Radius/Clients/wap_gateway.
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Configuration Examples
Note
The following shows an example configuration for a Query-Notify client:
[ //localhost/Radius/Clients/wap-gateway1 ]Name = wap-gateway1Description =IPAddress = 10.100.10.1SharedSecret = secretType = NASVendor =IncomingScript~ =OutgoingScript~ =EnableDynamicAuthorization = FALSENetMask =EnableNotifications = TRUENotificationProperties/Port = 1813InitialTimeout = 5000MaxTries = 3NotificationAttributeGroup = notifyGroupThe following shows an example configuration for a Query-Notify AttributeGroup:
[ //localhost/Radius/Advanced/AttributeGroups/notifyGroup ]Name = notifyGroupDescription =Attributes/1. User-Name2. Acct-Session-Id3. NAS-Identifier4. NAS-PortMemory and Performance Impact
Using the Query-Notify feature will have the following effects:
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Support for Windows Provisioning Service
CAR supports Microsoft's Windows Provisioning Service (WPS). WPS provides hotspot users with seamless service to public WLAN hotspots by using Microsoft Windows-based clients. The Microsoft WPS solution requires Microsoft-based software in the data center for the RADIUS server and the provisioning server.
Call Flow
The following is the WPS process and Wireless Internet Service Provider (WISP) packet sequence for a new wireless client login at a Wi-Fi hotspot location.
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The CAR server performs the following functions during WPS:
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The following is an example value for the URL PEAP-TLV:
http://www.example.com/provisioning/master.xml#sign up
Where #sign up is the parameter for this action and is a required element of the value.
The sign-up URL value is passed when the user authenticates as guest. The sign-up URL is a fragment within the Master URL. You can also configure other fragments to be returned in the Master URL. See Master URL Fragments, for more information about the different fragments.
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Example Configuration
The following shows an example configuration for the WPS feature:
[ //localhost/Radius/Services/peapv0 ]Name = peapv0Description =Type = peap-v0IncomingScript~ =OutgoingScript~ =MaximumMessageSize = 1024PrivateKeyPassword = <password>ServerCertificateFile = <path_to_ServerCertificateFile>ServerRSAKeyFile = <path_to_ServerRSAKeyFile>CACertificateFile = <path_to_CACertificateFile>CACertificatePath =<path_to_CACertificatePath>ClientVerificationMode = OptionalVerificationDepth = 4EnableSessionCache = TrueSessionTimeout = "5 Minutes"AuthenticationTimeout = 120TunnelService = eap-mschapv2EnableWPS = TrueMasterURL = http://www.example.com/provisioning/master.xmlWPSGuestUserProfile = WPS-Guest-User-ProfileWhen you set the EnableWPS property to TRUE, you must provide values for the properties MasterURL and WPSGuestUserProfile. See Environment Variables for more information.
Environment Variables
The two environment variables that is used to support WPS:
Send-PEAP-URI-TLV
Send-PEAP-URI-TLV is a Boolean value and provides a way in which the authenticating user service can let the PEAP-V0 service know to send the URI PEAP-TLV along. Under different circumstances CAR might send back different fragments within the MasterURL to the client, as described above.
The conditions under which this has to be sent is best known to the user authentication service (the service that is specified within the eap-mschapv2 service, which in turn is the tunnel service for PEAP-V0 service). So when it decides that it needs to send back the URL it can set this variable to TRUE. The default value for this is FALSE.
Master-URL-Fragment
The CAR authenticating user service uses Master-URL-Fragment to set the fragment within the Master URL that needs to be sent back. The CAR user authentication service sets the fragment to different values under different circumstances. While the Send-PEAP-URL-TLV indicates whether to send the URL or not, Master-URL-Fragment is used to intimate which fragment within the URL needs to be sent. If this variable is not set and if it is required to send the URL, `#signup' will be sent by default.
Master URL Fragments
This section describes the different fragments the RADIUS server might send to the AP in the Master URL.
Sign up
This value is passed when the user authenticates as guest. The following is an example value for the URL PEAP-TLV:
http://www.example.com/provisioning/master.xml#sign up
where #sign up is the parameter for this action and a required element of the value.
Renewal
This value is passed when the user's account is expired and needs renewal before network access can be granted. The following is an example value for the URL PEAP-TLV:
http://www.example.com/provisioning/master.xml#renewal
where #renewal is the parameter for this action and a required element of the value.
Password change
This value is passed when the user is required to change the account password. An example value for the URL PEAP-TLV is:
http://www.example.com/provisioning/master.xml#passwordchange
where #passwordchange is the parameter for this action and a required element of the value.
Force update
This value is passed when the WISP requires the Wireless Provisioning Services on the client to download an updated XML master file. This method of updating the XML master file on the client should be used only to correct errors; otherwise, the TTL expiry time in the XML master file is used to provide background updates. The following is an example value for the URL PEAP-TLV:
http://www.example.com/provisioning/master.xml#forceupdate
where #forceupdate is the parameter for this action and a required element of the value.
Unsupported Features
The following features are part of the Microsoft WPS functionality, but are not supported in the CAR.
Account Expiration and Renewal
When the user creates an account and logs in with that account, the RADIUS server authenticates and authorizes the request and sends back an Access-Accept with a Session-Timeout attribute. The Access Point (AP) then forces the wireless client to reauthenticate for every timeout value. When there is one timeout duration left in the user account, the RADIUS server needs to send back a renewal URL (a URL fragment within the master URL) to the client for the user to renew the account.
CAR does not support this feature because the interface the CAR server has with the AD (through the CiscoSecure Remote Agent) does not have provisions to get the expiration information of user account. However, this release does provide an environment variable to copy the URL fragment and to control whether or not to send the URL using another environment variable. This can be used to send the renewal URL. There are some limitations, however.
Password Changing and Force Update
The Password Changing option is passed when the user is required to change the account password. Force Update option is passed when the WISP requires the Wireless Provisioning Services on the client to download an updated XML master file.
These functions are not possible in this release for the same reason mentioned above, the loose coupling between CAR and the AD. Additionally, there is no known use case for this. As mentioned above, you can use the newly added environment variables to trigger these options.
Command Completion
CAR's command completion feature provides online help by listing possible entries to the current command line when you press the Tab key after entering a partial command. The Cisco AR 4.1 server responds based on:
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The command completion feature emulates the behavior of Cisco IOS and Kermit. When you press the Tab key after entering part of a command, the CAR server provides any identifiable object and property names. For example, after you first issue aregcmd and log in to CAR, enter the following:
cd <Tab>
Administrators/ Radius/Pressing the Tab key consecutively displays possible context-sensitive choices.
In the following example, after changing directory to /Radius/services/local-file an administrator wants to see the possible types of authentication services that can set.
cd /Radius/services/local-file
//localhost/Radius/Services/local-file ]Name = local-fileDescription =Type = fileIncomingScript~ =OutgoingScript~ =OutagePolicy~ = RejectAllOutageScript~ =FilenamePrefix = accountingMaxFileSize = "10 Megabytes"MaxFileAge = "1 Day"RolloverSchedule =set type <Tab>
eap-leap file local radius-sessioneap-md5 group odbc rexeap-sim ldap radius tacacs-udpValues can also be tab-completed. For example, if you decide to set the local-file service's type to file, you can do the following:
set type f<Tab>
and the command line completes to:
set type file
Service Grouping Feature
The Service Grouping feature enables you to specify multiple services (called subservices) to be used with authentication, authorization, or accounting requests. The general purpose is to enable multiple Remote Servers to process requests.
Perhaps the most common use of this feature will be to send accounting requests to multiple Remote Servers thus creating multiple accounting logs. Another common use might be to authenticate from more than one Remote Server where, perhaps the first attempt is rejected, other Remote Servers can be attempted and an Access-Accept obtained.
Clearly, in the accounting request example, each request must be successfully processed by each subservice in order for the originator of the accounting request to receive a response. This is known as a logical AND of each of the subservice results. In the authenticate example, the first subservice which responds with an accept is returned to the client or if all subservices respond with reject, then a reject is returned to the client. This is known as a logical OR of each of the subservice results.
A Service is specified as a Group Service by setting its type to group, specifying the ResultRule (AND or OR) and specifying one or more subservices in the GroupServices subdirectory. The subservices are called in numbered order and as such are in an indexed list similar to Remote Server specification in a radius Service. Incoming and outgoing scripts for the Group Service can be optionally specified.
A subservice is any configured non-Group Service. When a Group Service is used, each subservice is called in exactly the same manner as when used alone (such as if specified as the DefaultAuthenticationService). Incoming and Outgoing scripts are executed if configured and Outage Policies are honored.
Configuration Example - AccountingGroupService
The following example shows how to configure an accounting Group Service to deliver accounting requests to multiple Remote Servers.
Step 1
For this example, we will define two new radius Services called OurAccountingService and TheirAccountingService. A provider might want to maintain duplicate accounting logs in parallel with their bulk customer's accounting logs.
Step 2
cd /radius/services
[ //localhost/Radius/Services ]Entries 1 to 2 from 2 total entriesCurrent filter: <all>local-file/local-users/Step 3
add OurAccountingService
add TheirAccountingService
The configuration of these Services is very similar to stand-alone Radius accounting service. Step-by-step configuration instructions are not provided, but the complete configuration is shown below:
[ //localhost/Radius/Services/OurAccountingService ]Name = OurAccountingServiceDescription =Type = radiusIncomingScript = OurAccountingInScriptOutgoingScript = OurAccountingOutScriptOutagePolicy = RejectAllOutageScript =MultipleServersPolicy = FailoverRemoteServers/1. OurPrimaryServer2. OurSecondaryServer[ //localhost/Radius/Services/TheirAccountingService ]Name = TheirAccountingServiceDescription =Type = radiusIncomingScript = TheirAccountingInScriptOutgoingScript = TheirAccountingOutScriptOutagePolicy = RejectAllOutageScript =MultipleServersPolicy = FailoverRemoteServers/1. TheirPrimaryServer2. TheirSecondaryServerThe next step is to create the new AccountingGroupService. The purpose of this Service is to process Accounting requests through both OurAccountingService and TheirAccountingService.
Step 4
add AccountingGroupService
Added AccountingGroupServicecd AccountingGroupService
[ //localhost/Radius/Services/AccountingGroupService ]Name = AccountingGroupServiceDescription =Type =IncomingScript =OutgoingScript =set type group
Set Type groupStep 5
set ResultRule AND
Set ResultRule ANDls
[ //localhost/Radius/Services/AccountingGroupService ]Name = AccountingGroupServiceDescription =Type = groupIncomingScript =OutgoingScript =ResultRule = ANDGroupServices/set IncomingScript AcctGroupSvcInScript
set OutgoingScript AcctGroupSvcOutScript
Now we must add the Services we created OurAccountingService and TheirAccountingService as subservices of the Group Service.
Step 6
cd GroupServices
[ //localhost/Radius/Services/AccountingGroupService/GroupServices ]set 1 OurAccountingService
Set 1 OurAccountingServiceSet 2 TheirAccountingService
Set 2 TheirAccountingServicels
[ //localhost/Radius/Services/AccountingGroupService ]Name = AccountingGroupServiceDescription =Type = groupIncomingScript = AcctGroupSvcInScriptOutgoingScript = AcctGroupSvcOutScriptResultRule = ANDGroupServices/1. OurAccountingService2. TheirAccountingServiceThis completes the setup of the AccountingGroupService. To use this Service simply set it as the DefaultAccountingService and/or configure a policy/rule set which will select this Service. Essentially, this can be used in the same manner as any other stand-alone service.
Summary of Events
The following describes the flow of what happens when a client sends an accounting request which is processed by the AccountingGroupService:
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Configuration Example 2 - AuthenticationGroupService
In this example, we will configure a Group Service for the purposes of providing alternate Remote Servers for a single authentication. Simply put, if Service A rejects the request, try Service B.
Step 1
Step 2
cd /radius/services
[ //localhost/Radius/Services ]
Entries 1 to 2 from 2 total entries
Current filter: <all>
local-file/
local-users/
add AuthenticationServiceA
add AuthenticationServiceB
Step 3
[ //localhost/Radius/Services/AuthenticationServiceA ]
Name = AuthentictionServiceA
Description =
Type = radius
IncomingScript = AuthAInScript
OutgoingScript = AuthAOutScript
OutagePolicy = RejectAll
OutageScript = AuthAOutageScript
MultipleServersPolicy = Failover
RemoteServers/
1. PrimaryServerA
2. SecondaryServerA
[ //localhost/Radius/Services/AuthenticationServiceB ]
Name = AuthentictionServiceB
Description =
Type = radius
IncomingScript = AuthBInScript
OutgoingScript = AuthBOutScript
OutagePolicy = RejectAll
OutageScript = AuthBOutageScript
MultipleServersPolicy = Failover
RemoteServers/
1. PrimaryServerB
2. SecondaryServerB
The next step is to create the new "AuthenticationGroupService". The purpose of this Service is to process authentication requests through both AuthenticationServiceA and AuthenticationServiceB if AuthenticationServiceA rejects the request.
Step 4
add AuthenticationGroupService
Added AuthenticationGroupService
cd AuthenticationGroupService
[ //localhost/Radius/Services/AuthenticationGroupService ]
Name = AuthenticationGroupService
Description =
Type =
IncomingScript =
OutgoingScript =
set type group
Set Type group
Next set the ResultRule to OR because we want to ensure that if the first subservice rejects the request, we then try the second subservice. If the second subservice rejects the request, then the response to the client is a reject.
Step 5
set ResultRule OR
Set ResultRule OR
Set IncomingScript AuthGroupSvcInScript
Set OutgoingScript AuthGroupSvcOutScript
Set IncomingScript AuthGroupSvcInScript
Set OutgoingScript AuthGroupSvcOutScript
ls
[ //localhost/Radius/Services/AuthenticationGroupService ]
Name = AuthenticationGroupService
Description =
Type = group
IncomingScript = AuthGroupSvcInScript
OutgoingScript = AuthGroupSvcOutScript
ResultRule = OR
GroupServices/
Now we must add the services we created "AuthenticationServiceA" and "AuthenticationServiceB" as subservices of the Group Service.
Step 6
cd GroupServices
[ //localhost/Radius/Services/AuthenticationGroupService/GroupServices ]
set 1 AuthenticationServiceA
Set 1 AuthenticationServiceA
Set 2 AuthenticationServiceB
Set 2 AuthenticationServiceB
ls
[ //localhost/Radius/Services/AuthenticationGroupService ]
Name = AuthenticationGroupService
Description =
Type = group
IncomingScript = AuthGroupSvcInScript
OutgoingScript = AuthGroupSvcOutScript
ResultRule = OR
GroupServices/
1. AuthenticationServiceA
2. AuthenticationServiceB
This completes the setup of the AuthenticationGroupService. To use this Service simply set it as the DefaultAuthenticationService and/or configure a policy/rule set which will select this Service. Essentially, this can be used in the same manner as any other stand-alone Service.
Summary of Events
The following describes the flow of what happens when a client sends an Authentication request which is processed by the AuthenticationGroupService:
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10.
SHA-1 Support for LDAP-Based Authentication
The CAR server supports secure hash algorithm (SHA-1) for LDAP-based authentication. This feature enables the CAR server to authenticate users whose passwords are stored in LDAP servers and hashed using the SHA-1 encoding scheme.
SHA-1 support actually adds functionality for the following three features to CAR:
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This enhancement is 100% backwards compatible. All previously supported values for the PasswordEncryptionStyle property are still supported and still provide the same behavior. The only noticeable change is that dynamic is now the default value for the PasswordEncryptionStyle property.
Remote LDAP Server Password Encryption
Apart from the two values, none and crypt, of the PasswordEncryptionStyle property on a Remote LDAP Server, SHA-1 supports adds three additional values for the PasswordEncryptionStyle property. Table 16-2 lists the valid values for this property and describes the corresponding behavior.
Dynamic Password Encryption
When using the dynamic setting for the PasswordEncryptionStyle property on a Remote LDAP Server, the CAR server looks for the prefixes listed in Table 16-3 to determine if encryption or a hash algorithm should be used during password comparison.
Note
The default value for the PasswordEncryptionStyle property on a Remote LDAP Server is dynamic.
Note
Logs
Turn on trace to level 4 to indicate (via the trace log) which password comparison method is being used.
Dynamic Attributes
CAR supports dynamic values for the configuration object properties listed below. Dynamic attributes are similar to UNIX shell variables. With dynamic attributes, the value is evaluated at run time. All of the objects that support dynamic attributes will have validation turned off in aregcmd.
Object Properties with Dynamic Support
The following object properties support dynamic values:
Radius
DefaultAuthenticationService
DefaultAuthorizationService
DefaultAccountingService
DefaultSessionManager
IncomingScript
OutgoingScript
Note
Accounting-Service for the /Radius/DefaultAccountingService, Authentication-Service for the /Radius/DefaultAuthenticationService, or Authorization-Service for the /Radius/DefaultAuthorizationService
User-Profile for the BaseProfile, User-Group for the Group, User-Authorization for the AuthorizationScript, Session-Manager for the DefaultSessionManager, or Session-Service for the DefaultSessionService./Radius/Clients
client1/
IncomingScript
OutgoingScript
/Radius/Userlist/Default
user1/
Group
BaseProfile
AuthenticationScript
AuthorizationScript
/Radius/UserGroup
Group1/
BaseProfile
AuthenticationScript
AuthorizationScript
/Radius/Vendor
Vendor1/
IncomingScript
OutgoingScript
/Radius/Service
Service1/
IncomingScript
OutgoingScript
OutageScript
OutagePolicy
/Radius/RemoteServers
remoteserver1/
IncomingScript
OutgoingScript
Remoteldapserver1/
Searchpath
Filter
Note
Dynamic Attribute Format
The format of the dynamic attribute is:
${eqp|attribute-name}{default-name}
where e stands for environment dictionary, q stands for request dictionary and p stands for response dictionary. You can use e, q and p in any order. The attribute name is the name for the attribute from environment dictionary, request dictionary, or response dictionary.
For example,
/RadiusDefaultAuthenticationService = ${eq|realm}{local-users}The default Authentication Service is determined at run time. CAR first checks to see if there is one value of realm in the environment dictionary. If there is, it becomes the value of DefaultAuthenticationService. If there is not, check the value of realm in the request dictionary. If there is one value, it becomes the value of DefaultAuthenticationService. Otherwise, local-users is the DefaultAuthenticationService. If we don't set local-users as the default value, the DefaultAuthenticationService is null. The same concept applies to all other attribute properties.
The validation for the dynamic values of the object property will only validate the default value. In the above example, CAR will do validation to check whether local-users is one of services defined in the service subdirectory.
Note
Tunneling Support Feature
Tunneling support is strictly based upon the IETF RFC: "RADIUS Attributes for Tunnel Protocol Support" (http://www.ietf.org/rfc/rfc2868.txt).
Table 16-4 lists the tunneling attributes supported in this CAR release.
The tunneling attribute has the following format:
Configuration
1.
2.
Example
/Radius/Advanced/Attribute Dictionary /Tunnel-Client-ID Name = Tunnel-Client-Endpoint Description = Attribute = 66 Type = STRING Min = 0Max = 253/Radius/Profiles/testName = test Description = /Attributes Tunnel-Client-Endpoint_tag3 = "129.56.123.1"Notes
1.
2.
Validation
The CAR server checks whether the tag attributes are defined under the /Radius/Advanced/Attribute Dictionary directory. The server also checks whether the tag number falls within the range (0-31).
xDSL VPI/VCI Support for Cisco 6400
To provide this support, a distinction must be made between device authentication packets and regular user authentication packets.
Using User-Name/User-Password for Each Cisco 6400 Device
This approach assumes that for every 6400 NAS, a device-name/device-password is created for each. Following are the required changes:
For each NAS in CAR:
Name = test6400-1Description =IPAddress = 209.165.200.224SharedSecret = secretType = NASVendor =IncomingScript =OutgoingScript =Device-Name = theDeviceDevice-Password = thePasswordWhen the 6400 sends out the device authentication packet, it might have different User-Name/User-Password attributes for each 6400 NAS. When CAR receives the packet, it tries to obtain the Device-Name/Device-Password attributes from the NAS entry in the CAR configuration database. When the User-Name/User-Password in the packet match the configured Device-Name/Device-Password attribute values, CAR assumes that it must get the device. The next step is to replace the User-Name attribute with the concatenated <module>/<slot>/<port> string. From this point, the packet is treated as a regular packet.
Note
Format of the New User-Name Attribute
After the device is identified, the User-Name attribute is replaced with the new value. This new value is the concatenation of 6400 <module>/<slot>/<port> information from the NAS-Port attribute and the packet is treated as a regular user authentication from this point on.
Note
The format of the new User-Name attribute is the printf of "%s-%d-%d-%d-%d-%d" for the following values:
NAS-IP—in dot format of the NAS-Ip-Address attribute. For example, 10.10.10.10.
slot—apply mask 0xF0000000 on NAS-Port attribute and shift right 28 bits. For example, NAS-Port is 0x10000000, the slot value is 1.
module—apply mask 0x08000000 on NAS-Port attribute and shift right 27 bits. For example, NAS-Port is 0x08000000, the module value is 1.
port—apply mask 0x07000000 on NAS-Port attribute and shift right 24 bits. For example, NAS-Port is 0x06000000, the port value is 6.
VPI—apply mask 0x00FF0000 on NAS-Port attribute and shift right 16 bits. For example, NAS-Port is 0x00110000, the VPI value is 3.
VCI—apply mask 0x0000FFFF on NAS-Port attribute. For example, NAS-Port is 0x00001001, the VCI value is 9.
Apply Profile in Cisco Access Registrar Database to Directory Users
You can define the User-Profile and User-Group environment variables in the directory mapping and CAR will apply the profiles defined in the CAR database to each directory user having any of these two variables set.
User-Profile
This attribute is of type string with the format:
<Value1>::<Value2> ...
The User-Profile attribute is intended to hold a list of profile names. <Value1> and <Value2> represent the names of the profiles. They are separated by the "::" character, therefore, the "::" can not be part of the profile name. The order of values in the string has significance, as the profiles are evaluated from left to right. In this example, profile <Value2> is applied after profile <Value1>.
Assume the user record has a field called UserProfile that holds the name of the profile that applies to this user. This field is mapped to the environment attribute User-Profile. Following is how the mapping is done with aregcmd:
QuickExample/Name = QuickExampleDescription =Protocol = ldapIPAddress = 209.165.200.224Port = 389ReactivateTimerInterval = 300000Timeout = 15HostName = QuickExample.company.comBindName =BindPassword =UseSSL = FALSESearchPath = "o=Ace Industry, c=US"Filter = (uid=%s)UserPasswordAttribute = passwordLimitOutstandingRequests = FALSEMaxOutstandingRequests = 0MaxReferrals = 0ReferralAttribute =ReferralFilter =PasswordEncryptionStyle = NoneLDAPToEnvironmentMappings/UserProfile = User-ProfileLDAPToRadiusMappings/After CAR authenticates the user, it checks whether User-Profile exists in the environment dictionary. If it finds User-Profile, for each value in User-Profile, CAR looks up the profile object defined in the configuration database and adds all of the attributes in the profile object to the response dictionary. If any attribute is included in more than one profile, the newly applied profile overrides the attribute in the previous profile.
User-Group
You can use the User-Group environment variable to apply the user profile as well. In CAR, a user can belong to a user group, and that user group can have a pointer to a user profile. When CAR finds that a packet has User-Group set, it obtains the value of the User-Profile within the user group, and if the User-Profile exists, it applies the attributes defined in the user profile to that user.
Note that in CAR, every user can also directly have a pointer to a user profile. CAR applies profiles is in the following order:
1.
2.
The profile in User-Group is more generic than in User-Profile. Therefore, CAR applies the profile from generic to more specific.
Example User-Profile and User-Group Attributes in Directory User Record
You can use an existing user attribute in the user record to store profile info. When this is a new attribute, we suggest you create a new auxiliary class AR_UserRecord for whichever user class is used. AR_User_Profile and AR_User_Group are two optional members in this class. They are of type string. The mapping is as follows:
LDAPToEnvironmentMappings/AR_User_Profile = User-ProfileAR_User_Group = User-GroupDirectory Multi-Value Attributes Support
If any attributes mapped from the LDAP directory to the CAR response dictionary are multivalued, the attributes are mapped to multiple RADIUS attributes in the packet.
MultiLink-PPP (ML-PPP)
CAR supports MultiLink-PPP (ML-PPP). ML-PPP is an IETF standard, specified by RFC 1717. It describes a Layer 2 software implementation that opens multiple, simultaneous channels between systems, providing additional bandwidth-on-demand, for additional cost. The ML-PPP standard describes how to split, recombine, and sequence datagrams across multiple B channels to create a single logical connection. The multiple channels are the ports being used by the Network Access Server (NAS).
During the AA process, CAR authenticates the user connection for each of its channels, even though they belong to the same logical connection. The Authentication process treats the multilink connection as if it is multiple, single link connections. For each connection, CAR creates a session dedicated for management purposes. The session stays active until you logout, which subsequently frees up all of the ports in the NAS assigned to each individual session, or until the traffic is lower than a certain threshold so that the secondary B channels are destroyed thereafter. CAR has the responsibility of maintaining the active session list and discards any session that is no longer valid in the system, by using the accounting stop packet issued from NAS. The multiple sessions that were established for a single logical connection must be destroyed upon the user logging out.
In addition, the accounting information that was gathered for the sessions must be aggregated for the corresponding logical connection by the accounting software. CAR is only responsible for logging the accounting start and accounting stop times for each session. As those sessions belong to the same bundle, IETF provides two standard RADIUS attributes to identify the related multilink sessions. The attributes are Acct-Multi-Session-Id (attribute 50) and Acct-Link-Count (attribute 51), where Acct-Multi-Session-Id is a unique Accounting identifier used to link multiple related sessions in a log file, and Acct-Link-Count provides the number of links known to have existed in a given multilink session at the time the Accounting record was generated. The Accounting software is responsible for calculating the amount of the secondary B channel's connection time.
The secondary B channel can go up and down frequently, based upon traffic. The Ascend NAS supports the Target-Util attribute, which sets up the threshold for the secondary channel. When the traffic is above that threshold the secondary channel is up, and when the traffic is below that threshold, the secondary B channel is brought down by issuing an Accounting stop packet to CAR. On the other hand, if you bring down the primary channel (that is, log out), the secondary B channel is also destroyed by issuing another Accounting stop packet to CAR.
Table 16-5 lists ML-PPP related attributes.
Following are sample configurations for ML-PPP:
/Radius/Profile/Default-ISDN-UsersName = Default-ISDN-UsersDescription =Attributes/Port-Limit = 2Target-Util = 70Session-Timeout = 70/Radius/UserGroups/ISDN-UsersName = ISDN-UsersDescription = " Users who always use ISDN"BaseProfile = Default-ISDN-UsersAuthentication-Script =Authorization-Script =The Port-Limit attribute controls the number of concurrent sessions a user can have. The Target-Util attribute controls the threshold level at which the second B channel should be brought up.
Dynamic Updates Feature
The Dynamic Updates feature enables changes to server configurations made using aregcmd to take effect in the CAR server after issuing the save command, eliminating the need for a server reload after making changes.
Table 16-6 lists the Radius object and its child objects. For each object listed, the Add and Modify or Delete columns indicate whether a dynamic update occurs after adding, modifying, or deleting an object or attribute. Entries in the Add and Modify or Delete columns also apply to child objects and child attributes of the objects listed, unless the child object is explicitly listed below the object, such as /Radius/Advanced/Ports or /Radius/Advanced/Interfaces.
The Dynamic Updates feature is subject to the following limitations:
•
•
•
•
(/etc/init.d/arservagt restart)NAS Monitor
The ability to monitor when a NAS is down (really only unreachable from CAR) is provided by nasmonitor. This program will repeatedly query a TCP port at the specified IP address until the device (NAS) is reachable. If the NAS is not reachable after a period of time, a warning E-mail is sent; if the NAS is still not reachable after another period of time, a message is sent to CAR to release all sessions associated with that NAS. The port to query, the query frequency, the first time interval, the back-off time interval, and the E-mail address to send to are all configurable (with defaults); the only required parameter is the NAS IP address. This program will work for any device that has a TCP port open; it can either be run by hand, when desired, or put in a cron job. See nasmonitor -h for details.
Note
Automatic Information Collection (arbug)
You can use the script arbug to collect information about your CAR server. The results are collected into a tarball that can be E-mailed or ftped to Cisco as requested.
arbug collects all the relevant information needed to report a problem to CAR support. The goal of the arbug script is to make sure all the necessary information is collected.
Note
Running arbug
To run the arbug script, change directory to /cisco-ar/bin and enter the following:
./arbug
The following is a typical sequence.
Looking around...Cluster:User: adminPassword:The report /tmp/arbug.10085/arbug.tar is ready to send; youmay want to compress it first using gzip or compress.hostname user_name bin>Files Generated
The arbug script generates five files that are compressed into a tarball. Table 16-7 provides a summary of the information found in each of the files.
Simultaneous Terminals for Remote Demonstration
Multiple people can view and interact in a single demonstration by using the share-access program, a standard GNU release with a special configuration for use with CAR. To run screen, a technical support specialist (CSE or DE) will telnet to your server and log in as cisco. While you run /opt/CSCOar/bin/share-access (assuming /opt/CSCOar is the CAR path) as root, the CSE or DE runs /opt/CSCOar/bin/share-access -r root. Now both people (or more) can see what the other types, as well as the results of the commands entered. The special CAR configuration only allows root and cisco to run screen. To end a share-access session, type Control-D.
Support for RADIUS Check Item Attributes
CAR supports RADIUS check item attributes configuration at the user and group levels. You can configure the CAR server to check for attributes that must be present or attributes that must not be present in the Access-Request packet for successful authentication.
When using check item attributes, the CAR server will reject Access-Requests if:
•
•
For remote servers using either LDAP or ODBC, CAR allows for mapping of certain LDAP or ODBC fields to check item attributes. The mapped attributes can be used as check item attributes while processing the Access-Request packets.
When you configure check item attributes at both the user and group levels, the Cisco AR 4.1 server first checks the attributes of the user level before those of the group level. The Cisco AR 4.1 server must first authenticate the user's password in the Access-Request before validating the check item attributes.
The Cisco AR 4.1 server logs details about any rejected Access-Requests as a result of check items processing.
Configuring Check Items
You use aregcmd to configure check item attributes.
Configuring User Check Items
The following example shows how to configure UserList check item attributes.
Step 1
[ //localhost/Radius/UserLists/Default/bob ]Name = bobDescription =Password = <encrypted>AllowNullPassword = FALSEEnabled = TRUEGroup~ = PPP-usersBaseProfile~ =AuthenticationScript~ =AuthorizationScript~ =UserDefined1 =Attributes/CheckItems/Step 2
cd CheckItems
[ //localhost/Radius/UserLists/Default/bob/CheckItems ]Step 3
set calling-Station-Id 4085551212
save
Configuring Usergroup Check Items
The following example shows how to configure UserGroups check item attributes.
Step 1
cd /Radius/UserGroups/Default
[ //localhost/Radius/UserGroups/Default ]Name = DefaultDescription = "Users who sometimes connect using PPP and sometimes connect "BaseProfile~ =AuthenticationScript~ =AuthorizationScript~ = AuthorizeServiceAttributes/CheckItems/Step 2
cd CheckItems
[ //localhost/Radius/UserGroups/Default/CheckItems ]Step 3
set NAS-IP-Address 10.10.10.10
save
User-Specific Attributes
The CAR server supports user-specific attributes which enables the CAR server to return attributes on a per-user or per-group basis without having to use profiles.
The CAR server includes a property called HiddenAttributes to the User and UserGroup object. The HiddenAttributes property contains a concatenation of all user-level reply attributes. The HiddenAttributes property is not displayed, nor can the value be set or unset using the command-line interface.
The order of application of attributes is as follows:
1.
2.
3.
4.
The value of the HiddenAttributes property is used dynamically to construct and populate a virtual attributes directory in the User object. All values from the Attributes directory will go into the HiddenAttributes property. This occurs transparently when the administrator issues a save command.
Packet of Disconnect
CAR supports the Packet of Disconnect (POD) feature that enables the CAR server to send disconnect requests (PODs) to a NAS so that all the session information and the resources associated with the user sessions can be released. CAR can also determine when to trigger and send the POD.
For example, when a PDSN handoff occurs during a mobile session, the new PDSN sends out a new access-request packet to CAR for the same user. CAR should detect this handoff by the change in NAS-Identifier in the new request and trigger sending a POD to the old PDSN if it supports POD. CAR also provides an option for administrator to initiate sending POD requests through the command-line interface (CLI) for any user session. CAR forwards POD requests from external servers to the destination NAS.
Configuring Packet of Disconnect
This section describes how to configure the POD feature.
Note
Configuring the Client Object
You should enable POD for each client object that might want to send disconnect requests to those clients. You enable POD in a client object using the EnableDynamicAuthorization property. This property is set to FALSE by default when you create a client object. The following example shows the default configuration for a new client object, NAS1.
[ //localhost/Radius/Clients/NAS1 ]Name = nas1Description =IPAddress =SharedSecret =Type = NASVendor =IncomingScript~ =OutgoingScript~ =EnableDynamicAuthorization = FALSEIf the CAR server might send a POD to this client, set the EnableDynamicAuthorization property to TRUE. When you set this property to TRUE, the CAR server creates a DynamicAuthorizationServer subdirectory under the client object. The following example shows a newly created DynamicAuthorizationServer subdirectory:
[ //localhost/Radius/Clients/NAS1/DyanamicAuthorizationServer ]Port = 3799DynamicAuthSharedSecret =InitialTimeout = 5000MaxTries = 3PODAttributeGroup =COAAttributeGroup =The default port is 3799. You can change the port, if desired.
The property DynamicAuthSharedSecret is initially set to the same as value as the client's SharedSecret property when you set EnableDynamicAuthorization to TRUE. You can chose to configure a different secret for POD in this subdirectory.
The InitialTimeout property represents the number of milliseconds used as a timeout for the first attempt to send a POD packet to a remote server. For each successive retry on the same packet, the previous timeout value used is doubled. You must specify a number greater than zero, and the default value is 5000 (or 5 seconds).
The MaxTries property represents the number of times to send a proxy request to a remote server before deciding the server is off-line. You must specify a number greater than zero, and the default is 3.
The PODAttributeGroup property points to a group of attributes to be included in a disconnect-request packet sent to this client.
You can create and configure the PODAttributeGroup in the /Radius/Advanced/AttributeGroups/ directory. The default group contains commonly used POD attributes NAS-Port and Acct-Session-Id.
The COAAttributeGroup property is used with the Change of Authorization (CoA) feature, also knows as hot-lining.
Configuring a Resource Manager for POD
CAR provides a resource manager type called session-cache. When you set a resource manager to session-cache, the resource manager's configuration contains a subdirectory called AttributesToBeCached. The following is an example Resource Manager set to type session-cache:
[ //localhost/Radius/ResourceManagers/PODresourceMgr ]Name = PODresourceMgrDescription =Type = session-cacheOverwriteAttributes = FALSEAttributesToBeCached/QueryMappings/The attributes you configure under the AttributesToBeCached directory are cached in the session record during session management. The cached attributes are then sent in the disconnect-request for this session.
The OverwriteAttributes property indicates whether to overwrite the existing attributes if there are any in the session record. Since this resource manager can be invoked during Access-Request as well as Accounting-Start processing, the OverwriteAttributes can be used to control if the attributes cached during Access-Request processing can be overwritten with the attributes available during Accounting-Start processing.
The following is an example of a typical session-cache resource manager:
[ //localhost/Radius/ResourceManagers/RM-New ]Name = RM-NewDescription =Type = session-cacheOverwriteAttributes = TRUEAttributesToBeCached/1. Framed-IP-Address2. CDMA-Correlation-IDQueryMappings/The attributes used in the example can be added as an indexed list using add or set commands (in any order).
Proxying POD Requests from External Servers
CAR can also proxy the disconnect requests received from external servers. To make CAR listen for external POD requests, the ListenForDynamicAuthorizationRequests property under /Radius/Advanced should be set to TRUE. The default value for this is FALSE. The default POD listening port is 3799. However this can be changed by configuring a new port of type pod under /Radius/Advanced/Ports and setting the new port number accordingly.
For security reasons, the source of a POD request should be configured as a remote server in CAR and the remote server should be configured to accept PODs. Set the property AcceptDynamicAuthorizationRequests to TRUE to do this. The default for this is FALSE. POD requests from unauthorized sources are silently discarded.
CLI Options for POD
CAR has options for the query-sessions and release-sessions CLI commands that enable querying or releasing sessions based on the session's age. Another option enables querying or releasing sessions based on any valid RADIUS attribute available in the user's session record.
query-sessions
The syntax for using query-sessions with-Age option is the following:
query-sessions <path> with-Age <value>
Where <path> is the path to the server, session-manager or resource manager and <value> is the minimum age of the session specified in minutes or hours with options M, Minutes, H or Hours. This command returns all sessions that are older than the given age value.
The syntax for using query-sessions with-Attribute option is the following:
query-sessions <path> with-Attribute <name> <value>
Where <name> is the RADIUS attribute name and <value> is the value of the attribute to be matched. This command returns the sessions where a session record contains and matches the attribute value specified in <value> field.
release-sessions
The syntax for using release-sessions with-Age option is:
release-sessions <path> with-Age <value>
Where, <path> is the path to the server, session-manager or resource manager and <value> is the minimum age of the session specified in minutes or hours with options M for Minutes, H for Hours. This command returns all sessions that are older than the given age value.
The syntax for using release-sessions with-Attribute option is:
release-sessions <path> with-Attribute <name> <value>
Where, <name> is the RADIUS attribute name and <value> is the value of the attribute to be matched. This command returns the sessions where a session record contains and matches the attribute value specified in <value> field.
A new option is also available for release-sessions command to enable an administrator to trigger sending a POD for a user after the session is released.
release-sessions <path> with-<type> <value> [send-pod]
Where, <path> is the path to the server, Session Manager, or Resource Manager and <type> is one of the following: NAS, User, IP-Address ID, or Age. The release-sessions command with an optional [send-pod] at the end results in CAR sending a POD request. The PoD requests are directed to port number configured in /radius/clients/<client name>/DynamicAuthorizationServer/port. By default it is set to 3799. To configure udp xxx, set the port value as:
/radius/clients/<client name>/DynamicAuthorizationServer/port = xxx
Configuring Change of Authorization Requests
CAR supports Change of Authorization (CoA) requests as defined in Internet RFC 3576 that provides a way to change authorization status of users already logged on to the network. The CoA feature, also known as hot-lining, provides a wireless operator the ability to efficiently address issues with users that might otherwise be unauthorized to access packet data services. When a problem occurs that causes a user to be unauthorized to use the packet data service, a wireless operator can use the CoA feature to resolve the problem and return the user's packet data services.
When a user is hot-lined, their packet data service is redirected to a to a hot-line application that notifies the user of issues that might be blocking their access to normal packet data services. Hot-lining provides users with a way to address the issues blocking their access, such as billing issues, a prepaid account that has been depleted, or an expired credit card.
The CoA feature provides an option to the wireless operator administrator to send CoA packets to the client device when a user needs to be hot-lined. When to send a CoA request to a user depends on the wireless operator's site-specific policies.
Configuring the Client Object
You should enable CoA for each client object that might want to send CoA requests to those clients. You enable CoA in a client object using the EnableDynamicAuthorization property. This property is set to FALSE by default when you create a client object. The following example shows the default configuration for a new client object, NAS1.
[ //localhost/Radius/Clients/NAS1 ]Name = nas1Description =IPAddress =SharedSecret =Type = NASVendor =IncomingScript~ =OutgoingScript~ =EnableDynamicAuthorization = FALSEIf the CAR server might send a CoA request to this client, set the EnableDynamicAuthorization property to TRUE. When you set this property to TRUE, the CAR server creates a DynamicAuthorizationServer subdirectory under the client object. The following example shows a newly created DynamicAuthorizationServer subdirectory:
[ //localhost/Radius/Clients/NAS1/COA ]Port = 3799DynamicAuthSharedSecret =InitialTimeout = 5000MaxTries = 3PODAttributeGroup =COAAttributeGroup =The default port is 3799. You can change the port, if desired.
The property DynamicAuthSharedSecret is initially set to the same as value as the client's SharedSecret property when you set EnableDynamicAuthorization to TRUE. You can chose to configure a different secret for CoA in this subdirectory.
The InitialTimeout property represents the number of milliseconds used as a timeout for the first attempt to send a CoA packet to a remote server. For each successive retry on the same packet, the previous timeout value used is doubled. You must specify a number greater than zero, and the default value is 5000 (or 5 seconds).
The MaxTries property represents the number of times to send a proxy request to a remote server before deciding the server is off-line. You must specify a number greater than zero, and the default is 3.
The COAAttributeGroup property points to a group of attributes to be included in a CoA request packet sent to this client.
You can create and configure the COAAttributeGroup in the /Radius/Advanced/AttributeGroups/ directory. The default group is not set to any value by default. When an attribute group is configured, the CAR server includes the attributes in this group in a CoA request. The values for these attributes are fetched from the user's session record.
The CoA attribute group configuration can be used with a session-cache Resource Manager. For example, any new attributes that are to be sent in a CoA request can be configured for caching by the session-cache Resource Manager so they will be available in the session record when it is to be sent in the CoA request.
The CoA request might also contain AV pairs from the optional profile name in the query-session CLI command used to send the CoA request. In a 3GPP2 scenario, a profile containing the Filter-Id attribute set to a value "Hot-Line Active" can be included when a user is to be hot-lined. This can be used as a hot-line profile possibly containing other attributes as desired by the wireless operator. Another profile might be defined containing the Filter-Id attribute with the value "Hot-Line Normal." This profile can be used with the query-session CLI command to bring the user back to normal.
The CoA request packet sent by the CAR server conforms to internet RFC 3756. In response to a CoA request initiated by the CAR server, the client should respond with a COA-ACK if it is able to hot-line the user based on credentials available in the CoA request. If the client is unable to hot-line the user for any reason, the client can include an error-cause attribute with the appropriate reason in a COA-NAK packet.
The CAR server logs all CoA responses. If the CAR server does not receive a response to a CoA request within the timeout period, it will retransmit for the configured number of retries, then logs an error if no response is received.
The CAR server forwards proxied CoA requests sent by external servers to the destination NAS. The CoA requests are proxied based on the NAS-IP-Address in the incoming request. The proxied CoA requests from external servers are forwarded to the destination NAS only if the source IP address is configured to accept dynamic authorization requests. The responses received from the NAS (either COA-ACK or COA-NAK) are forwarded back to the source where the CAR server received the original proxy request.
Dynamic DNS
CAR supports the Dynamic DNS protocol providing the ability to update DNS servers. The dynamic DNS updates contain the hostname/IP Address mapping for sessions managed by CAR.
You enable dynamic DNS updates by creating and configuring new Resource Managers and new Remote Servers, both of type dynamic-dns. The dynamic-dns Resource Managers specify which zones to use for the forward and reverse zones and which Remote Servers to use for those zones. The dynamic-dns Remote Servers specify how to access the DNS Servers.
Configuring Dynamic DNS
Before you configure CAR you need to gather information about your DNS environment. For a given Resource Manager you must decide which forward zone you will be updating for sessions the resource manager will manage. Given that forward zone, you must determine the IP address of the primary DNS server for that zone. If the dynamic DNS updates will be protected with TSIG keys, you must find out the name and the base64 encoded value of the secret for the TSIG key. If the resource manager should also update the reverse zone (ip address to host mapping) for sessions, you will also need to determine the same information about the primary DNS server for the reverse zone (IP address and TSIG key).
If using TSIG keys, use aregcmd to create and configure the keys. You should set the key in the Remote Server or the Resource Manager, but not both. Set the key on the Remote Server if you want to use the same key for all of the zones accessed through that Remote Server. Otherwise, set the key on the Resource Manager. That key will be used only for the zone specified in the Resource Manager.
Step 1
Step 2
cd /Radius/Advanced/DDNS/TSIGKeys
add foo.com
This example named the TSIG Key, foo.com, which is related to name of the example DNS server we use. You should choose a name for TSIG keys that reflects the DDNS client-server pair (for example, foo.bar if the client is foo and the server is bar), but you should use the name of the TSIG Key as defined in the DNS server.
Step 3
cd foo.com
set Secret <base64-encoded string>
The Secret should be set to the same base64-encoded string as defined in the DNS server. If there is a second TSIG Key for the primary server of the reverse zone, follow these steps to add it, too.
Step 4
Step 5
cd /Radius/RemoteServers
add ddns
This example named the remote server ddns which is the related to the remote server type. You can use any valid name for your remote server.
Step 6
cd ddns
set Protocol dynamic-dns
set IPAddress 10.10.10.1 (ip address of primary dns server for zone)
set ForwardZoneTSIGKey foo.com
set ReverseZoneTSIGKey foo.com
If the reverse zone will be updated and if the primary server for the reverse zone is different than the primary server for the forward zone, you will need to add another Remote Server. Follow the previous two steps to do so. Note that the IP Address and the TSIG Key will be different.
You can now use aregcmd to create and configure a resource manager of type dynamic-dns.
Step 7
cd /Radius/ResourceManagers
add ddns
This example named the service ddns which is the related to the resource manager type but you can use any valid name for your resource manager.
Step 8
cd ddns
set Type dynamic-dns
set ForwardZone foo.com
set ForwardZoneServer DDNS
Finally, reference the new resource manager from a session manager. Assuming that the example configuration was installed, the following step will accomplish this. If you have a different session manager defined you can add it there if that is appropriate.
Step 9
cd /Radius/SessionManagers/session-mgr-1/ResourceManagers
set 5 DDNS
Note
Step 10
Testing Dynamic DNS with radclient
After the Resource Manager has been defined it must be referenced from the appropriate Session Manager. You can use radclient to confirm that dynamic DNS has been properly configured and is operational.
To test Dynamic DNS using radclient, follow these steps:
Step 1
aregcmd
Login to the Cisco AR 4.1 server as an administrative user.
trace 4
Step 2
cd /opt/CSCOar/bin
radclient
Step 3
acct_request Start username
Example:
set p [ acct_request Start bob ]
Step 4
Step 5
$p send
Step 6
Dynamic Service Authorization Feature
Typically, CAR does not allow sending another Access-Request to remote server after the user is connected to the LDAP servers for user authentication. The Dynamic Service Authorization feature allows you to access external databases such as LDAP and Oracle first to know which remote servers authenticated services need to be relayed. This feature enables CAR to determine whether to send access-accept back to the client or to send another access-request to the remote server such as LDAP and Oracle. CAR is able to perform this activity multiple times in a single access-request.
Configuring Dynamic Service Authorization Feature
Configuring the dynamic service authorization involves:
•
Setting up the Environment Variable
Before configuring the dynamic service authorization feature, you must set the following three environment variables in CAR:
•
When the Re-Authentication-Service is set, the server directs the request to the specified reauthentication service for processing.
•
When the Re-Authorization-Service is set, the server directs the request to the specified reauthorization service for processing.
•
When the Re-Accounting-Service is set, the server directs the request to the specified reaccounting service for processing.
You can set the environmental variable by using scripts. See Writing the Script, page 10-2 for more information.
Note
Following is a sample procedure for setting the environment variable:
proc dynamicservice { request response environ } {$environ put Re-Authentication-Service "local-users"$environ put Re-Authorization-Service "local-users"}You can append this procedure by copying it into tclscript.tcl that is located in /opt/CSCOar/scripts/radius/tcl directory, or to the location that you chose when you installed CAR. You can also use this procedure as a separate script file and configure the script accordingly. See Adding the CheckEap.tcl Script, page 14-15 for more information on configuring the TCL script.
Configuring the Script
To configure the script for the dynamic service authorization feature:
Step 1
aregcmd
Step 2
cd /Radius/Scripts
Step 3
Step 4
cd dynamicservice
You get the following output:
[ //localhost/Radius/Scripts/dynamicservice ] Name = dynamicservice Description = Language =Step 5
Set Language TCL
Step 6
Set Filename tclscript.tcl
Step 7
Set EntryPoint dynamicservice
The following is an example of the script configuration:
cd /Radiusset IncomingScript dynamicservice [ //localhost/Radius ]IncomingScript~ = dynamicserviceDefaultAuthenticationService~ = local-usersDefaultAuthorizationService~ = local-usersStep 8
The following shows a sample trace:
10/30/2008 12:32:02.258: P577: Packet received from 127.0.0.110/30/2008 12:32:02.259: P577: Packet successfully added10/30/2008 12:32:02.259: P577: Trace of Access-Request packet10/30/2008 12:32:02.259: P577: identifier = 910/30/2008 12:32:02.259: P577: length = 6110/30/2008 12:32:02.259: P577: reqauth = b6:89:41:52:6e:d4:86:37:4a:aa:9b:27:1f:74:ff:0510/30/2008 12:32:02.259: P577: User-Name = bob10/30/2008 12:32:02.259: P577: User-Password = 2b:4a:f0:c8:95:f1:ad:e5:52:d4:83:0f:45:2b:2b:7010/30/2008 12:32:02.259: P577: NAS-Port = 210/30/2008 12:32:02.260: P577: NAS-Identifier = localhost10/30/2008 12:32:02.260: P577: Running Server's IncomingScript: dynamicservice10/30/2008 12:32:02.261: P577: Tcl: environ put Re-Authentication-Service local-users -> OK10/30/2008 12:32:02.261: P577: Tcl: environ put Re-Authorization-Service local-users -> OK10/30/2008 12:32:02.261: P577: Using Client: localhost10/30/2008 12:32:02.262: P577: Using NAS: localhost (127.0.0.1)10/30/2008 12:32:02.262: P577: Request is directly from a NAS: TRUE10/30/2008 12:32:02.262: P577: Authenticating and Authorizing with Service local-users10/30/2008 12:32:02.262: P577: Getting User bob's UserRecord from UserList Default10/30/2008 12:32:02.263: P577: user list user bob's password matches10/30/2008 12:32:02.263: P577: Processing UserGroup PPP-users's check items10/30/2008 12:32:02.263: P577: User bob is part of UserGroup PPP-users10/30/2008 12:32:02.263: P577: Merging UserGroup PPP-users's BaseProfiles into response dictionary10/30/2008 12:32:02.264: P577: Merging BaseProfile default-PPP-users into response dictionary10/30/2008 12:32:02.264: P577: Merging attributes into the Response Dictionary:10/30/2008 12:32:02.264: P577: Adding attribute Service-Type, value = Framed10/30/2008 12:32:02.264: P577: Adding attribute Framed-Protocol, value = PPP10/30/2008 12:32:02.264: P577: Adding attribute Framed-Routing, value = None10/30/2008 12:32:02.264: P577: Adding attribute Framed-MTU, value = 150010/30/2008 12:32:02.264: P577: Adding attribute Framed-Compression, value = VJ TCP/IP header compression10/30/2008 12:32:02.264: P577: Adding attribute Ascend-Idle-Limit, value = 180010/30/2008 12:32:02.265: P577: Merging UserGroup PPP-users's Attributes into response Dictionary10/30/2008 12:32:02.265: P577: Merging attributes into the Response Dictionary:10/30/2008 12:32:02.265: P577: Authenticating and Authorizing with Service local-users10/30/2008 12:32:02.265: P577: Getting User bob's UserRecord from UserList Default10/30/2008 12:32:02.266: P577: user list user bob's password matches10/30/2008 12:32:02.266: P577: Processing UserGroup PPP-users's check items10/30/2008 12:32:02.266: P577: User bob is part of UserGroup PPP-users10/30/2008 12:32:02.266: P577: Merging UserGroup PPP-users's BaseProfiles into response dictionary10/30/2008 12:32:02.266: P577: Merging BaseProfile default-PPP-users into response dictionary10/30/2008 12:32:02.266: P577: Merging attributes into the Response Dictionary:10/30/2008 12:32:02.266: P577: Replacing attribute Service-Type, new value = Framed10/30/2008 12:32:02.267: P577: Replacing attribute Framed-Protocol, new value = PPP10/30/2008 12:32:02.267: P577: Replacing attribute Framed-Routing, new value = None10/30/2008 12:32:02.267: P577: Replacing attribute Framed-MTU, new value = 1500
