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Table Of Contents
Prerequisites for Configuring AAA for VPDNs
Information About AAA for VPDNs
VPDN Tunnel Authorization Search Order
VPDN Tunnel Lookup Based on Domain Name
VPDN Tunnel Lookup Based on DNIS Information
VPDN Tunnel Lookup Based on Both Domain Name and DNIS Information
VPDN Tunnel Lookup Based on the Multihop Hostname
VPDN Authorization for Directed Request Users
Domain Name Prefix and Suffix Stripping
RADIUS Tunnel Accounting for L2TP VPDNs
VPDN-Specific Remote RADIUS AAA Server Configurations
L2TP Forwarding of PPPoE Tagging Information
Benefits of LNS Address Checking
LNS Address Checking Using a RADIUS Server
Debugging Dropped Control Packets
Modified LNS Dead-Cache Handling
How to Configure AAA for VPDNs
Enabling VPDN on the NAS and the Tunnel Server
Configuring the VPDN Tunnel Authorization Search Order
Configuring per-User VPDN on the NAS
Configuring Global per-User VPDN
Configuring per-User VPDN for a VPDN Group
Configuring AAA on the NAS and the Tunnel Server
Configuring Remote AAA for VPDNs
Configuring the NAS for Remote AAA for Dial-In VPDNs
Configuring the Tunnel Terminator for Remote RADIUS AAA for L2TP Tunnels
Verifying and Troubleshooting Remote AAA Configurations
Verifying that the VPDN Tunnel Is Up
Verifying the Remote RADIUS AAA Server Configuration
Verifying the Remote TACACS+ AAA Server Configuration on the NAS
Verifying the Remote TACACS+ AAA Server Configuration on the Tunnel Server
Verifying L2TP Tunnel Establishment, PPP Negotiations, and Authentication with the Remote Client
Configuring Directed Request Authorization of VPDN Users
Configuring Directed Request Authorization of VPDN Users on the Tunnel Server
Configuring Directed Request Authorization of VPDN Users on the NAS
Configuring Domain Name Prefix and Suffix Stripping
Configuring VPDN Tunnel Authentication
Configuring VPDN Tunnel Authentication Using the Hostname
Configuring VPDN Tunnel Authentication Using the Local Name
Configuring VPDN Tunnel Authentication Using the L2TP Tunnel Password
Disabling VPDN Tunnel Authentication for L2TP Tunnels
Configuring RADIUS Tunnel Accounting for L2TP VPDNs
Configuring Authentication of L2TP Tunnels at the Tunnel Terminator Remote RADIUS AAA Server
Configuring Tunnel Assignments on the NAS Remote RADIUS AAA Server
Configuring Secure Tunnel Authentication Names on the NAS Remote RADIUS AAA Server
Configuring L2TP Forwarding of PPPoE Tagging Information
Configuring L2TP Forwarding of PPPoE Tagging Information
Overriding L2TP Forwarding of PPPoE Tag Information
Removing L2TP Forwarding of PPPoE Tag Information
Displaying the Session Activity Log
Configuring L2TP Override Forwarding rx-speed and tx-speed Values Received from PPPoE
Configuring rx-speed and tx-speed Values When the RADIUS Server Is Not Used
Configuring rx-speed and tx-speed Values on the RADIUS Server
Configuring rx-speed and tx-speed Values from ANCP on the RADIUS Server
Configuring rx-speed and tx-speed Values from RAM-min on the RADIUS Server
Configuring LNS Address Checking
Configuring Modified LNS Dead-Cache Handling
Identifying an LNS in a Dead-Cache State
Clearing an LNS in a Dead-Cache State
Generating an SNMP Event for a Dead-Cache Entry
Generating a Syslog Event for a Dead-Cache Entry
Configuration Examples for AAA for VPDNs
Examples: Configuring the VPDN Tunnel Authorization Search Order
Examples: Configuring per-User VPDN on the NAS
Examples: Configuring AAA on the NAS and the Tunnel Server
Examples: Configuring Remote AAA for VPDNs on the L2TP Tunnel Terminator
Examples: Configuring Directed Request Authorization of VPDN Users
Examples: Configuring Domain Name Prefix and Suffix Stripping
Examples: Configuring VPDN Tunnel Authentication
Example: Configuring RADIUS Tunnel Accounting on a NAS
Example: Configuring RADIUS Tunnel Accounting on a Tunnel Server
Example: Configuring Tunnel Assignments on the NAS RADIUS AAA Server
Examples: Configuring rx-speed and tx-speed Values
Example: Configuring Secure Authentication Names
Examples: Configuring LNS Address Checking
Examples: Configuring Modified LNS Dead-Cache Handling
Feature Information for AAA for VPDNs
Configuring AAA for VPDNs
First Published: September 26, 2005Last Updated: November 24, 2010This module describes how to configure authentication, authorization, and accounting (AAA) for virtual private dialup networks (VPDNs).
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the "Feature Information for AAA for VPDNs" section.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Contents
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Prerequisites for Configuring AAA for VPDNs
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Prerequisites for Configuring AAA for VPDNs
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Information About AAA for VPDNs
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VPDN Tunnel Authorization Search Order
When a call to a network access server (NAS) is to be tunneled to a tunnel server, the NAS must identify which tunnel server to forward the call to. The router can authorize users and select the outgoing tunnel based on the domain portion of the username, the Dialed Number Identification Service (DNIS) number, the multihop hostname, or any combination of these three parameters in a specified order. The default search order for VPDN tunnel authorization is to first search by DNIS, then by domain.
These sections contain information on VPDN tunnel lookup criteria:
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VPDN Tunnel Lookup Based on Domain Name
When a NAS is configured to forward VPDN calls on the basis of the user domain name, the user must use a username of the form username@domain. The NAS then compares the user domain name to the domain names it is configured to search for. When the NAS finds a match, it forwards the user call to the proper tunnel server.
VPDN Tunnel Lookup Based on DNIS Information
When a NAS is configured to forward VPDN calls on the basis of the user DNIS information, the NAS identifies the user DNIS information, which is provided on ISDN lines, and then forwards the call to the proper tunnel server.
The ability to select a tunnel on the basis of DNIS information provides additional flexibility to network service providers that offer VPDN services and to the companies that use the services. Instead of using only the domain name for tunnel selection, the NAS can use dialed number information for tunnel selection.
With this feature, a company—which might have only one domain name—can provide multiple specific phone numbers for users to dial in to the NAS at the service provider point of presence (POP). The service provider can select the tunnel to the appropriate services or portion of the company network on the basis of the dialed number.
VPDN Tunnel Lookup Based on Both Domain Name and DNIS Information
When a service provider has multiple AAA servers configured, VPDN tunnel authorization searches based on domain name can be time consuming and might cause the client session to time out.
To provide more flexibility, service providers can configure the NAS to perform tunnel authorization searches by domain name only, by DNIS only, or by both in a specified order.
VPDN Tunnel Lookup Based on the Multihop Hostname
If a device will function as a multihop tunnel switch, tunnel authorization searches can be performed based on the multihop hostname. Configuring a multihop hostname on a tunnel switch allows authorization searches to be based on the identity of the peer device that initiated the tunnel. The multihop hostname can be the hostname of the remote peer that initiated the ingress tunnel, or the tunnel ID associated with the ingress tunnel.
A multihop tunnel switch can be configured to perform authorization searches by multihop hostname only, by domain name only, by DNIS only, or by any combination of these searches in a specified order.
Per-User VPDN AAA
If remote AAA is used for VPDN, the NAS that receives the call from a user forwards information about that user to its remote AAA server. With basic VPDN, the NAS sends the user domain name when performing authentication based on domain name or the telephone number the user dialed in from when performing authentication based on DNIS.
When per-user VPDN is configured, the entire structured username is sent to a RADIUS AAA server the first time the router contacts the AAA server. This enables Cisco IOS XE software to customize tunnel attributes for individual users that use a common domain name or DNIS.
Without VPDN per-user configuration, Cisco IOS XE software sends only the domain name or DNIS to determine VPDN tunnel attribute information. Then, if no VPDN tunnel attributes are returned, Cisco IOS XE software sends the entire username string.
VPDN Authorization for Directed Request Users
Directed requests allow users logging in to a NAS to select a RADIUS server for authorization. With directed requests enabled, only the portion of the username before the "@" symbol is sent to the host specified after the "@" symbol. Using directed requests, authorization requests can be directed to any of the configured servers, and only the username is sent to the specified server.
Domain Name Prefix and Suffix Stripping
When a user connects to a NAS configured to use a remote server for AAA, the NAS forwards the username to the remote AAA server. Some RADIUS or TACACS+ servers require the username to be in a particular format, which might be different from the format of the full username. For example, the remote AAA server might require the username to be in the format user@domain.com, but the full username could be prefix/user@domain.com@suffix. Configuring domain name stripping allows the NAS to strip incompatible portions from the full username before forwarding the reformatted username to the remote AAA server.
The NAS can be configured to perform in these ways:
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VPDN Tunnel Authentication
VPDN tunnel authentication enables routers to authenticate the other tunnel endpoint before establishing a VPDN tunnel. VPDN tunnel authentication is optional for L2TP tunnels.
For additional information on configuring VPDN tunnel authentication for client-initiated VPDN tunneling deployments, see the "Configuring VPDN Tunnel Authentication" section.
VPDN tunnel authentication can be performed in these ways:
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For L2TP tunnels only, a remote RADIUS AAA server can be used to perform VPDN tunnel authentication on the VPDN tunnel terminator as follows:
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For detailed information on configuring remote RADIUS or TACACS+ servers, see the "Additional References" section.
RADIUS Tunnel Accounting for L2TP VPDNs
RADIUS tunnel accounting for VPDNs is supported by RFC 2867, which introduces six new RADIUS accounting types. Without RADIUS tunnel accounting support, VPDN with network accounting will not report all possible attributes to the accounting record file. RADIUS tunnel accounting support allows users to determine tunnel-link status changes. Because all possible attributes can be displayed, users can better verify accounting records with their Internet service providers (ISPs).
Enabling tunnel type accounting records allows the router to send tunnel and tunnel-link accounting records to the RADIUS server. The two types of accounting records allow the identification of VPDN tunneling events as described next.
Tunnel-Type Accounting Records
AAA sends Tunnel-Start, Tunnel-Stop, or Tunnel-Reject accounting records to the RADIUS server to identify these events:
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Tunnel-Link-Type Accounting Records
AAA sends Tunnel-Link-Start, Tunnel-Link-Stop, or Tunnel-Link-Reject accounting records to the RADIUS server to identify these events:
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VPDN-Specific Remote RADIUS AAA Server Configurations
The RADIUS attributes are specific to VPDN configurations. For detailed information on configuring remote RADIUS or TACACS+ servers, see the "Additional References" section.
VPDN-specific RADIUS attributes provide this functionality:
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L2TP Forwarding of PPPoE Tagging Information
The L2TP Forwarding of PPPoE Tag Information feature allows you to transfer DSL line information from the L2TP access concentrator (LAC) to the L2TP network server (LNS). For example, the LAC transports the actual-rate-up and the actual-rate-down PPPoE tag information to the LNS, which learns about the actual PPPoE transfer speeds that are negotiated by the customer premise equipment (CPE) and the digital subscriber line access multiplexer (DSLAM). The DSLAM inserts the PPPoE tag values for the rate up and the rate down and signals this information during PPPoE establishment with the LAC, which in turn, sends this information to the LNS.
By using the L2TP Forwarding of PPPoE Tag Information feature, you can also override the nas-port-id or calling-station-id VSAs, or both, on the LNS with the Circuit-ID and Remote-ID VSA respectively.
When you configure the dsl-line-info-forwarding command in VPDN group or VPDN-template configuration mode, and when the LNS receives one of the specified AV pairs, the LNS sends a matching VSA to the RADIUS server as a AAA request. The associated AAA attributes are:
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Enter the radius-server attribute 87 circuit-id command to override the nas-port-id with the CIRCUIT_ID VSA. Enter the radius-server attribute 31 remote-id command to override the calling-station-id with the REMOTE_ID VSA.
In accordance with DSL Forum 2004-71, the DSL uses the Vendor Specific tag for line identification. The first 2 octets (TAG_TYPE) are PPPOE_TAG_VENDSPEC (0x0105). The next 2 octets (TAG_LENGTH) contain the total length including Sub-options, Sub-option-lengths, and Tag-values. The first four octets of the TAG_VALUE contain the vendor ID. The next octet contains sub-option for Agent Remote ID (0x02). Following octet contains total length of Sub-option-tag in bytes.
The maximum length for the Remote-ID tag is 63 bytes. The Remote-ID tag contains an operator administered string that uniquely identifies the subscriber on the associated DSL line. The Remote-ID tag can be a phone number, an email address, a billing account number, or any other string that can be used by Service Providers as a tracking mechanism.
If the discovery frame has the sub-option 0x01, it indicates the presence of the Circuit-ID tag. A single frame supports Circuit-ID, Remote-ID, or both. If Circuit-ID is present in the same frame, it sends to the RADIUS server through the Nas-Port-ID attribute.
The following example shows an access and accounting request sent to the RADIUS server with remote-ID tag and DSL-Sync-Rate tags:
01:24:52: RADIUS/ENCODE: Best Local IP-Address 10.0.73.20 for Radius-Server 128.107.164.25401:24:52: RADIUS(00000011): Send Access-Request to 192.107.164.254:1645 id 1645/3, len 39101:24:52: RADIUS: authenticator 3B 49 F5 7D 8A 6F A4 D7 - 57 99 E6 60 A9 D0 C7 B901:24:52: RADIUS: Vendor, Cisco [26] 4101:24:52: RADIUS: Cisco AVpair [1] 35 "client-mac-address=0090.bf06.c81c"01:24:52: RADIUS: Vendor, Cisco [26] 3901:24:52: RADIUS: Cisco AVpair [1] 33 "actual-data-rate-upstream=20480"01:24:52: RADIUS: Vendor, Cisco [26] 3901:24:52: RADIUS: Cisco AVpair [1] 33 "actual-data-rate-downstream=512"01:24:52: RADIUS: Vendor, Cisco [26] 3901:24:52: RADIUS: Cisco AVpair [1] 33 "minimum-data-rate-upstream=1024"01:24:52: RADIUS: Framed-Protocol [7] 6 PPP [1]01:24:52: RADIUS: User-Name [1] 16 "pshroff-client"01:24:52: RADIUS: CHAP-Password [3] 19 *01:24:52: RADIUS: NAS-Port-Type [61] 6 Ethernet [15]01:24:52: RADIUS: Vendor, Cisco [26] 4601:24:52: RADIUS: Cisco AVpair [1] 40 "circuit-id-tag=Ethernet1/0.1:ababababa"01:24:52: RADIUS: Vendor, Cisco [26] 3601:24:52: RADIUS: Cisco AVpair [1] 30 "remote-id-tag=0090.bf06.c81c"01:24:52: RADIUS: NAS-Port [5] 6 26843548601:24:52: RADIUS: NAS-Port-Id [87] 25 "Ethernet1/0.1:ababababa"01:24:52: RADIUS: Vendor, Cisco [26] 4101:24:52: RADIUS: Cisco AVpair [1] 35 "client-mac-address=0090.bf06.c81c"01:24:52: RADIUS: Service-Type [6] 6 Framed [2]01:24:52: RADIUS: NAS-IP-Address [4] 6 10.0.73.2001:24:55: RADIUS(00000011): Send Accounting-Request to 192.107.164.254:1646 id 1646/4, len 49501:24:55: RADIUS: authenticator 22 6F B2 F3 88 B1 03 91 - 4A 70 53 BD 44 A6 A6 0F01:24:55: RADIUS: Acct-Session-Id [44] 19 "1/0/0/30_00000008"01:24:55: RADIUS: Vendor, Cisco [26] 3901:24:55: RADIUS: Cisco AVpair [1] 33 "actual-data-rate-upstream=20480"01:24:55: RADIUS: Vendor, Cisco [26] 3901:24:55: RADIUS: Cisco AVpair [1] 33 "actual-data-rate-downstream=512"01:24:55: RADIUS: Vendor, Cisco [26] 3901:24:55: RADIUS: Cisco AVpair [1] 33 "minimum-data-rate-upstream=1024"01:24:55: RADIUS: Vendor, Cisco [26] 4901:24:55: RADIUS: Cisco AVpair [1] 43 "minimum-data-rate-downstream-low-power=32"01:24:55: RADIUS: Vendor, Cisco [26] 4601:24:55: RADIUS: Cisco AVpair [1] 40 "maximum-interleaving-delay-upstream=64"01:24:55: RADIUS: Framed-Protocol [7] 6 PPP [1]01:24:55: RADIUS: User-Name [1] 16 "pshroff-client"01:24:55: RADIUS: Vendor, Cisco [26] 3201:24:55: RADIUS: Cisco AVpair [1] 26 "connect-progress=Call Up"01:24:55: RADIUS: Acct-Authentic [45] 6 RADIUS [1]01:24:55: RADIUS: Acct-Status-Type [40] 6 Start [1]01:24:55: RADIUS: NAS-Port-Type [61] 6 Ethernet [15]01:24:55: RADIUS: Vendor, Cisco [26] 4601:24:55: RADIUS: Cisco AVpair [1] 40 "circuit-id-tag=Ethernet1/0.1:ababababa"01:24:55: RADIUS: Vendor, Cisco [26] 3601:24:55: RADIUS: Cisco AVpair [1] 30 "remote-id-tag=0090.bf06.c81c"01:24:55: RADIUS: NAS-Port [5] 6 26843548601:24:55: RADIUS: NAS-Port-Id [87] 25 "Ethernet1/0.1:ababababa"01:24:55: RADIUS: Vendor, Cisco [26] 4101:24:55: RADIUS: Cisco AVpair [1] 35 "client-mac-address=0090.bf06.c81c"01:24:55: RADIUS: Service-Type [6] 6 Framed [2]01:24:55: RADIUS: NAS-IP-Address [4] 6 10.0.73.2001:24:55: RADIUS: Acct-Delay-Time [41] 6 001:24:57: RADIUS: Received from id 1646/4 192.107.164.254:1646, Accounting-response, len 20The LAC sends the indicated AV pairs, containing the DSL line information to the LNS, which sends them through AAA to the RADIUS server. The RADIUS server uses the DSL line identification when processing AAA requests.
If you plan to configure L2TP Forwarding of PPPoE Tagging Information, it is recommended that you be familiar with RFC 2516 and DSL Forum TR-101 before configuring this feature. See the "RFCs" section and the "Standards" section for pointers to this RFC and Standard.
DSL Sync-Rate VSAs
The DSL uses PPPoE Vendor Specific tags for Sync-Rate tag information. DSL Sync-Rates are encoded as 32-bit binary values, describing the rate in kbps. The tag length is 4 bytes. Table 1 shows the mandatory DSL Sync-Rate tags and their associated RADIUS VSA.
PADI/PADR frames might contain an optional DSL Sync-Rate tag. Table 2 shows DSL line information and their associated RADIUS VSA for the optional DSL Sync-Rate tags.
LNS Address Checking
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Benefits of LNS Address Checking
The LNS Address Checking feature allows a LAC to check the IP address of the LNS sending traffic to it during the setup of an L2TP tunnel, thus providing a check for uplink and downlink traffic arriving from different interfaces.
The benefit of the LNS Address Checking feature is avoiding the loss of revenue from users sending back traffic through an alternate network.
LNS Address Checking Using a RADIUS Server
Use the Cisco attribute-value pair (AVP), downloaded from a RADIUS server during authentication, to enable IP address checking at the LAC.
The Cisco AVP is:
l2tp-security-ip-address-check=yes
The following RADIUS profile example shows the LNS address checking enabled:
example.com Password="example"Service-Type=OutboundCisco-Avpair="vpdn:tunnel-id=tunnel"Cisco-Avpair="vpdn:tunnel-type=l2tp"Cisco-Avpair="vpdn:ip-address=10.10.10.1"Cisco-Avpair="vpdn:l2tp-tunnel-password=example"Cisco-Avpair="vpdn:l2tp-security-ip-address-check=yes"Debugging Dropped Control Packets
Use the LNS Address Checking feature to help troubleshoot dropped control packets. If you configure the debug vpdn 12x-error command, informational messages display for each control packet that is dropped in the following format:
Tnl <tunnel-ID> L2TP: Drop <L2TP-packet-name> from y.y.y.y (attempted) x.x.x.xModified LNS Dead-Cache Handling
The Modified LNS Dead-Cache Handling feature allows you to display and clear (restart) any Layer 2 Tunnel Protocol (L2TP) network server (LNS) entry in a dead-cache (DOWN) state. You can use this feature to generate a Simple Network Management Protocol (SNMP) or system message log (syslog) event when an LNS enters or exits a dead-cache state. Once an LNS exits the dead-cache state, the LNS is able to establish new sessions.
Prior to Cisco IOS XE Release 2.4, networks could not identify the status of a Load Sharing Group (LSG) on a LAC. As a result, it was not possible to know if an LNS is not responding (dead-cache state). An LNS in a dead-cache state causes an LSG to reject a call from an LAC.
Networks also have no method of logging, either though a syslog or SNMP event, when an LNS enters, or is cleared from a dead-cache state.
The Modified LNS Dead-Cache Handling feature allows you to view (identify) and clear (restart) one or more LNS entries in a dead-cache (DOWN) state, and generate either a syslog or SNMP event when an LNS exits or enters a dead-cache state. Once an LNS clears a dead-cache state, the LNS is active and available for new call-session establishments.
How to Configure AAA for VPDNs
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Enabling VPDN on the NAS and the Tunnel Server
Before performing any VPDN configuration tasks, you must enable VPDN on the NAS and the tunnel server. If you are deploying a multihop VPDN tunnel switching architecture, you must enable VPDN must on the tunnel switch as well.
Perform this task on all required devices to enable VPDN.
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DETAILED STEPS
What to Do Next
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Configuring the VPDN Tunnel Authorization Search Order
The default search order for VPDN tunnel authorization is to first search by DNIS, then by domain.
Perform this task on the NAS or the tunnel switch to configure the VPDN tunnel authorization search order if you prefer to use an order other than the default order.
Prerequisites
You must perform the task in the "Enabling VPDN on the NAS and the Tunnel Server" section.
Restrictions
Tunnel authorization searches based on the multihop hostname are supported only for multihop tunnel switching deployments.
SUMMARY STEPS
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What to Do Next
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Configuring per-User VPDN on the NAS
Per-user VPDN can be configured globally, or for individual VPDN groups. The VPDN group configuration will take precedence over the global configuration.
Perform one of these tasks on the NAS to configure per-user VPDN:
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Prerequisites
The NAS remote RADIUS server must be configured for AAA. See the "Additional References" section.
Restrictions
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Configuring Global per-User VPDN
Configuring per-user VPDN on a NAS causes the NAS to send the entire structured username of the user to a RADIUS AAA server the first time the NAS contacts the AAA server. Per-user VPDN can be configured globally, or for individual VPDN groups. Configuring per-user VPDN globally will apply per-user VPDN to all request-dialin VPDN groups configured on the NAS.
Perform this task on the NAS to configure global per-user VPDN.
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What to Do Next
You can perform the optional task in the "Configuring AAA on the NAS and the Tunnel Server" section.
Configuring per-User VPDN for a VPDN Group
Configuring per-user VPDN on a NAS causes the NAS to send the entire structured username of the user to a RADIUS AAA server the first time the NAS contacts the AAA server. Per-user VPDN can be configured globally, or for individual VPDN groups. Configuring per-user VPDN at the VPDN group level will apply per-user VPDN only to calls associated with that specific VPDN group
Perform this task on the NAS to configure per-user VPDN for a specific VPDN group.
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What to Do Next
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Configuring AAA on the NAS and the Tunnel Server
For NAS-initiated dial-in VPDN tunneling and L2TP dial-out tunneling deployments, perform this task on the NAS and the tunnel server.
For client-initiated dial-in VPDN tunneling, perform this task on the tunnel server.
Prerequisites
You must perform the task in the "Enabling VPDN on the NAS and the Tunnel Server" section.
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What to Do Next
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Configuring Remote AAA for VPDNs
A remote RADIUS or TACACS+ AAA server can be used for tunnel authentication. For detailed information on configuring remote RADIUS or TACACS+ servers, see the "Additional References" section.
Remote AAA authentication can be configured on the NAS or the tunnel server in these ways:
Dial-In Configurations
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Dial-Out Configurations
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Perform one of these tasks to configure remote AAA for VPDNs:
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Configuring the NAS for Remote AAA for Dial-In VPDNs
Perform this task to configure the NAS to use a remote RADIUS or TACACS+ server for tunnel authentication. This task applies only to dial-in VPDN configurations.
Prerequisites
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tacacs-server host {host-name | host-ip-address} [key string] [nat] [port [integer]] [single-connection] [timeout [integer]]4.
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aaa group server tacacs+ group-name5.
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server ip-addressDETAILED STEPS
What to Do Next
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Configuring the Tunnel Terminator for Remote RADIUS AAA for L2TP Tunnels
You can configure the device that terminates the L2TP VPDN tunnel to perform remote RADIUS AAA. Without this functionality, the tunnel terminator can only perform L2TP authentication locally. Local authentication requires that data about the corresponding tunnel endpoint be configured within a VPDN group. This mechanism does not scale well because the information stored in the VPDN groups on each device must be updated independently.
Remote RADIUS authentication allows users to store configurations on the RADIUS server, avoiding the need to store information locally. New information can be added to the RADIUS server as needed, and a group of tunnel terminators can access a common database on the RADIUS server.
Perform this task to configure remote RADIUS AAA for L2TP tunnels on the tunnel terminator. This task can be performed on the tunnel server for dial-in VPDN tunnels, or on the NAS for dial-out VPDN tunnels.
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What to Do Next
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Verifying and Troubleshooting Remote AAA Configurations
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Verifying that the VPDN Tunnel Is Up
Perform this task to verify that the VPDN tunnel is up.
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Step 1
Enter this command to enable privileged EXEC mode. Enter your password if prompted:
Router> enableStep 2
Enter this command to display information about active VPDN tunnels. At least one tunnel and one session must be set up.
Router# show vpdn tunnelL2TP Tunnel and Session Information Total tunnels 1 sessions 1LocID RemID Remote Name State Remote Address Port Sessions VPDN Group4571 61568 csidtw13 est 10.0.195.4 1701 1 ?LocID RemID TunID Intf Username State Last Chg4 11 4571 Vi4.1 csidtw9@cisco.com est 00:02:29%No active PPPoE tunnels
Verifying the Remote RADIUS AAA Server Configuration
Perform this task to verify that the remote AAA authorization server is configured on the tunnel endpoint and that the tunnel endpoint can receive attributes 90 and 69 from the RADIUS server.
In this example the steps are performed on the tunnel server, which is performing remote RADIUS AAA as a tunnel terminator. These steps can also be performed on the NAS when remote RADIUS AAA is being performed on the NAS as a tunnel initiator for dial-in VPDNs or as a tunnel terminator for dial-out VPDNs.
SUMMARY STEPS
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DETAILED STEPS
Step 1
Enter this command to enable privileged EXEC mode. Enter your password if prompted:
Router> enableStep 2
Enter this command on the tunnel server to display RADIUS debugging messages.
Step 3
Enter this command on the tunnel server to display the contents of the standard system logging message buffer. Ensure that "access-accept" is in the output and that attributes 90 and 69 can be seen in the RADIUS reply, as shown in bold.
Router# show logging00:32:56: RADIUS: Received from id 21645/5 172.19.192.50:1645, Access-Accept, len 8100:32:56: RADIUS: authenticator 73 2B 1B C2 33 71 93 19 - 62 AC 3E BE 0D 13 14 8500:32:56: RADIUS: Service-Type [6] 6 Outbound [5]00:32:56: RADIUS: Tunnel-Type [64] 6 00:L2TP [3]00:32:56: RADIUS: Tunnel-Medium-Type [65] 6 00:IPv4 [1]00:32:56: RADIUS: Tunnel-Client-Auth-I[90] 6 00:"csidtw13"00:32:56: RADIUS: Tunnel-Password [69] 8 *00:32:56: RADIUS: Vendor, Cisco [26] 2900:32:56: RADIUS: Cisco AVpair [1] 23 "vpdn:vpdn-vtemplate=1"
Verifying the Remote TACACS+ AAA Server Configuration on the NAS
Perform this task on the NAS to verify that the remote TACACS+ AAA server is properly configured.
Prerequisites
Enable these debug commands before performing this task:
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SUMMARY STEPS
1.
2.
3.
DETAILED STEPS
Step 1
Enter this command to enable privileged EXEC mode. Enter your password if prompted:
Router> enableStep 2
Enter this command to display information about the types of debugging that are enabled for your router.
Router# show debuggingGeneral OS:AAA Authentication debugging is onAAA Authorization debugging is onAAA Accounting debugging is onVPN:L2X protocol events debugging is onL2X protocol errors debugging is onVPDN events debugging is onVPDN errors debugging is onVTEMPLATE:Virtual Template debugging is on!Step 3
The following example shows complete debug output from the NAS for successful VPDN tunnel establishment using remote TACACS+ AAA authentication at the NAS:
Jan 30 12:17:09: As1 AAA/AUTHOR/FSM: (0): LCP succeeds trivially20:03:18: %LINK-3-UPDOWN: Interface Async1, changed state to upJan 30 12:17:09: As1 VPDN: Looking for tunnel -- rtp.cisco.com --Jan 30 12:17:09: AAA: parse name=Async1 idb type=10 tty=1Jan 30 12:17:09: AAA: name=Async1 flags=0x11 type=4 shelf=0 slot=0 adapter=0port=1 channel=0Jan 30 12:17:09: AAA/AUTHEN: create_user (0x278B90) user='rtp.cisco.com'ruser=''port='Async1' rem_addr='' authen_type=NONE service=LOGIN priv=0Jan 30 12:17:09: AAA/AUTHOR/VPDN (898425447): Port='Async1' list='default'service=NETJan 30 12:17:09: AAA/AUTHOR/VPDN: (898425447) user='rtp.cisco.com'Jan 30 12:17:09: AAA/AUTHOR/VPDN: (898425447) send AV service=pppJan 30 12:17:09: AAA/AUTHOR/VPDN: (898425447) send AV protocol=vpdnJan 30 12:17:09: AAA/AUTHOR/VPDN (898425447) found list "default"Jan 30 12:17:09: AAA/AUTHOR/VPDN: (898425447) Method=TACACS+Jan 30 12:17:09: AAA/AUTHOR/TAC+: (898425447): user=rtp.cisco.comJan 30 12:17:09: AAA/AUTHOR/TAC+: (898425447): send AV service=pppJan 30 12:17:09: AAA/AUTHOR/TAC+: (898425447): send AV protocol=vpdnJan 30 12:17:09: TAC+: (898425447): received author response status = PASS_ADDJan 30 12:17:09: AAA/AUTHOR (898425447): Post authorization status = PASS_ADDJan 30 12:17:09: AAA/AUTHOR/VPDN: Processing AV service=pppJan 30 12:17:09: AAA/AUTHOR/VPDN: Processing AV protocol=vpdnJan 30 12:17:09: AAA/AUTHOR/VPDN: Processing AV tunnel-type=l2tpJan 30 12:17:09: AAA/AUTHOR/VPDN: Processing AV tunnel-id=rtp_tunnelJan 30 12:17:09: AAA/AUTHOR/VPDN: Processing AV ip-addresses=10.31.1.56Jan 30 12:17:09: As1 VPDN: Get tunnel info for rtp.cisco.com with NASrtp_tunnel, IP 10.31.1.56Jan 30 12:17:09: AAA/AUTHEN: free_user (0x278B90) user='rtp.cisco.com' ruser=''port='Async1' rem_addr='' authen_type=NONE service=LOGIN priv=0Jan 30 12:17:09: As1 VPDN: Forward to address 10.31.1.56Jan 30 12:17:09: As1 VPDN: Forwarding...Jan 30 12:17:09: AAA: parse name=Async1 idb type=10 tty=1Jan 30 12:17:09: AAA: name=Async1 flags=0x11 type=4 shelf=0 slot=0 adapter=0port=1 channel=0Jan 30 12:17:09: AAA/AUTHEN: create_user (0x22CDEC) user='user1@rtp.cisco.com'ruser='' port='Async1' rem_addr='async' authen_type=CHAPservice=PPP priv=1Jan 30 12:17:09: As1 VPDN: Bind interface direction=1Jan 30 12:17:09: Tnl/Cl 74/1 L2TP: Session FS enabledJan 30 12:17:09: Tnl/Cl 74/1 L2TP: Session state change from idle towait-for-tunnelJan 30 12:17:09: As1 74/1 L2TP: Create sessionJan 30 12:17:09: Tnl 74 L2TP: SM State idleJan 30 12:17:09: Tnl 74 L2TP: O SCCRQJan 30 12:17:09: Tnl 74 L2TP: Tunnel state change from idle to wait-ctl-replyJan 30 12:17:09: Tnl 74 L2TP: SM State wait-ctl-replyJan 30 12:17:09: As1 VPDN: user1@rtp.cisco.com is forwardedJan 30 12:17:10: Tnl 74 L2TP: I SCCRP from ABCDEJan 30 12:17:10: Tnl 74 L2TP: Got a challenge from remote peer, ABCDEJan 30 12:17:10: AAA: parse name= idb type=-1 tty=-1Jan 30 12:17:10: AAA/AUTHEN: create_user (0x23232C) user='rtp_tunnel'ruser='' port=''rem_addr='' authen_type=CHAP service=PPP priv=1Jan 30 12:17:10: AAA/AUTHEN/START (1598999635): port='' list='default'action=SENDAUTH service=PPPJan 30 12:17:10: AAA/AUTHEN/START (1598999635): found list defaultJan 30 12:17:10: AAA/AUTHEN (1598999635): status = UNKNOWNJan 30 12:17:10: AAA/AUTHEN/START (1598999635): Method=TACACS+Jan 30 12:17:10: TAC+: send AUTHEN/START packet ver=193 id=1598999635Jan 30 12:17:10: TAC+: ver=192 id=1598999635 received AUTHEN status = ERRORJan 30 12:17:10: AAA: parse name= idb type=-1 tty=-1Jan 30 12:17:10: AAA/AUTHEN: create_user (0x232470) user='rtp_tunnel'ruser='' port=''rem_addr='' authen_type=CHAP service=PPP priv=1Jan 30 12:17:10: TAC+: ver=192 id=3400389836 received AUTHEN status = PASSJan 30 12:17:10: AAA/AUTHEN: free_user (0x232470) user='rtp_tunnel'ruser='' port=''rem_addr='' authen_type=CHAP service=PPP priv=1Jan 30 12:17:10: AAA/AUTHEN (1598999635): status = PASSJan 30 12:17:10: AAA/AUTHEN: free_user (0x23232C) user='rtp_tunnel'ruser='' port=''rem_addr='' authen_type=CHAP service=PPP priv=1Jan 30 12:17:10: Tnl 74 L2TP: Got a response from remote peer, ABCDEJan 30 12:17:10: AAA: parse name= idb type=-1 tty=-1Jan 30 12:17:10: AAA/AUTHEN: create_user (0x22FBA4) user='rtp_tunnel'ruser='' port=''rem_addr='' authen_type=CHAP service=PPP priv=1Jan 30 12:17:10: AAA/AUTHEN/START (2964849625): port='' list='default'action=SENDAUTH service=PPPJan 30 12:17:10: AAA/AUTHEN/START (2964849625): found list defaultJan 30 12:17:10: AAA/AUTHEN (2964849625): status = UNKNOWNJan 30 12:17:10: AAA/AUTHEN/START (2964849625): Method=TACACS+Jan 30 12:17:10: TAC+: send AUTHEN/START packet ver=193 id=296484962520:03:20: %LINEPROTO-5-UPDOWN: Line protocol on Interface Async1,changed state to upJan 30 12:17:11: TAC+: ver=192 id=2964849625 received AUTHEN status = ERRORJan 30 12:17:11: AAA: parse name= idb type=-1 tty=-1Jan 30 12:17:11: AAA/AUTHEN: create_user (0x22FC8C) user='rtp_tunnel'ruser='' port=''rem_addr='' authen_type=CHAP service=PPP priv=1Jan 30 12:17:11: As1 74/1 L2TP: Discarding data packet because tunnelis not openJan 30 12:17:11: As1 74/1 L2TP: Discarding data packet because tunnelis not openJan 30 12:17:11: TAC+: ver=192 id=1474818051 received AUTHEN status = PASSJan 30 12:17:11: AAA/AUTHEN: free_user (0x22FC8C) user='rtp_tunnel'ruser='' port=''rem_addr='' authen_type=CHAP service=PPP priv=1Jan 30 12:17:11: AAA/AUTHEN (2964849625): status = PASSJan 30 12:17:11: AAA/AUTHEN: free_user (0x22FBA4) user='rtp_tunnel'ruser='' port=''rem_addr='' authen_type=CHAP service=PPP priv=1Jan 30 12:17:11: Tnl 74 L2TP: Tunnel Authentication successJan 30 12:17:11: Tnl 74 L2TP: Tunnel state change from wait-ctl-reply toestablishedJan 30 12:17:11: Tnl 74 L2TP: O SCCCN to ABCDE tnlid 56Jan 30 12:17:11: Tnl 74 L2TP: SM State establishedJan 30 12:17:11: As1 74/1 L2TP: O ICRQ to ABCDE 56/0Jan 30 12:17:11: As1 74/1 L2TP: Session state change from wait-for-tunnelto wait-replyJan 30 12:17:11: Tnl 74 L2TP: Dropping old CM, Ns 0, expected 1Jan 30 12:17:11: As1 74/1 L2TP: O ICCN to ABCDE 56/1Jan 30 12:17:11: As1 74/1 L2TP: Session state change from wait-reply toestablished
Verifying the Remote TACACS+ AAA Server Configuration on the Tunnel Server
Perform this task on the tunnel server to verify that the remote TACACS+ AAA server is properly configured.
Prerequisites
Enable these debug commands before performing this task:
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SUMMARY STEPS
1.
2.
3.
DETAILED STEPS
Step 1
Enter this command to enable privileged EXEC mode. Enter your password if prompted:
Router> enableStep 2
Enter this command to display information about the types of debugging that are enabled for your router.
Router# show debuggingGeneral OS:AAA Authentication debugging is onAAA Authorization debugging is onAAA Accounting debugging is onVPN:L2X protocol events debugging is onL2X protocol errors debugging is onVPDN events debugging is onVPDN errors debugging is onVTEMPLATE:Virtual Template debugging is onStep 3
The following example shows complete debug output from the tunnel server for successful VPDN tunnel establishment using remote TACACS+ AAA authentication at the NAS:
Jan 30 12:17:09: L2TP: I SCCRQ from rtp_tunnel tnl 74Jan 30 12:17:09: Tnl 56 L2TP: New tunnel created for remotertp_tunnel, address 10.31.1.144Jan 30 12:17:09: Tnl 56 L2TP: Got a challenge in SCCRQ, rtp_tunnelJan 30 12:17:09: AAA: parse name= idb type=-1 tty=-1Jan 30 12:17:09: AAA/AUTHEN: create_user (0x21F6D0) user='ABCDE'ruser='' port=''rem_addr='' authen_type=CHAP service=PPP priv=1Jan 30 12:17:09: AAA/AUTHEN/START (3194595626): port='' list='default'action=SENDAUTH service=PPPJan 30 12:17:09: AAA/AUTHEN/START (3194595626): found list defaultJan 30 12:17:09: AAA/AUTHEN (3194595626): status = UNKNOWNJan 30 12:17:09: AAA/AUTHEN/START (3194595626): Method=TACACS+Jan 30 12:17:09: TAC+: send AUTHEN/START packet ver=193 id=3194595626Jan 30 12:17:09: TAC+: ver=192 id=3194595626 received AUTHEN status = ERRORJan 30 12:17:09: AAA: parse name= idb type=-1 tty=-1Jan 30 12:17:09: AAA/AUTHEN: create_user (0x2281AC) user='ABCDE'ruser='' port=''rem_addr='' authen_type=CHAP service=PPP priv=1Jan 30 12:17:09: TAC+: ver=192 id=3639011179 received AUTHEN status = PASSJan 30 12:17:09: AAA/AUTHEN: free_user (0x2281AC) user='ABCDE' ruser='' port=''rem_addr='' authen_type=CHAP service=PPP priv=1Jan 30 12:17:09: AAA/AUTHEN (3194595626): status = PASSJan 30 12:17:09: AAA/AUTHEN: free_user (0x21F6D0) user='ABCDE' ruser='' port=''rem_addr='' authen_type=CHAP service=PPP priv=1Jan 30 12:17:09: Tnl 56 L2TP: O SCCRP to rtp_tunnel tnlid 74Jan 30 12:17:09: Tnl 56 L2TP: Tunnel state change from idle towait-ctl-replyJan 30 12:17:10: Tnl 56 L2TP: O Resend SCCRP, flg TLF, ver 2, len 152,tnl 74, cl 0, ns 0, nr 1Jan 30 12:17:10: Tnl 56 L2TP: I SCCCN from rtp_tunnel tnl 74Jan 30 12:17:10: Tnl 56 L2TP: Got a Challenge Response in SCCCN from rtp_tunnelJan 30 12:17:10: AAA: parse name= idb type=-1 tty=-1Jan 30 12:17:10: AAA/AUTHEN: create_user (0x227F3C) user='ABCDE'ruser='' port=''rem_addr='' authen_type=CHAP service=PPP priv=1Jan 30 12:17:10: AAA/AUTHEN/STARTTranslating "rtp.cisco.com"(4117701992): port='' list='default' action=SENDAUTH service=PPPJan 30 12:17:10: AAA/AUTHEN/START (4117701992): found list defaultJan 30 12:17:10: AAA/AUTHEN (4117701992): status = UNKNOWNJan 30 12:17:10: AAA/AUTHEN/START (4117701992): Method=TACACS+Jan 30 12:17:10: TAC+: send AUTHEN/START packet ver=193 id=4117701992Jan 30 12:17:11: TAC+: ver=192 id=4117701992 received AUTHEN status = ERRORJan 30 12:17:11: AAA: parse name= idb type=-1 tty=-1Jan 30 12:17:11: AAA/AUTHEN: create_user (0x228E68) user='ABCDE' ruser='' port=''rem_addr='' authen_type=CHAP service=PPP priv=1Jan 30 12:17:11: TAC+: ver=192 id=2827432721 received AUTHEN status = PASSJan 30 12:17:11: AAA/AUTHEN: free_user (0x228E68) user='ABCDE' ruser='' port=''rem_addr='' authen_type=CHAP service=PPP priv=1Jan 30 12:17:11: AAA/AUTHEN (4117701992): status = PASSJan 30 12:17:11: AAA/AUTHEN: free_user (0x227F3C) user='ABCDE' ruser='' port=''rem_addr='' authen_type=CHAP service=PPP priv=1Jan 30 12:17:11: Tnl 56 L2TP: Tunnel Authentication successJan 30 12:17:11: Tnl 56 L2TP: Tunnel state change from wait-ctl-replyto establishedJan 30 12:17:11: Tnl 56 L2TP: SM State establishedJan 30 12:17:11: Tnl 56 L2TP: I ICRQ from rtp_tunnel tnl 74Jan 30 12:17:11: Tnl/Cl 56/1 L2TP: Session FS enabledJan 30 12:17:11: Tnl/Cl 56/1 L2TP: Session state change from idle towait-for-tunnelJan 30 12:17:11: Tnl/Cl 56/1 L2TP: New session createdJan 30 12:17:11: Tnl/Cl 56/1 L2TP: O ICRP to rtp_tunnel 74/1Jan 30 12:17:11: Tnl/Cl 56/1 L2TP: Session state change from wait-for-tunnelto wait-connectJan 30 12:17:11: Tnl/Cl 56/1 L2TP: I ICCN from rtp_tunnel tnl 74, cl 1Jan 30 12:17:11: Tnl/Cl 56/1 L2TP: Session state change from wait-connectto establishedJan 30 12:17:11: Vi1 VTEMPLATE: Reuse Vi1, recycle queue size 0Jan 30 12:17:11: Vi1 VTEMPLATE: Hardware address 00e0.1e68.942cJan 30 12:17:11: Vi1 VPDN: Virtual interface created for user1@rtp.cisco.comJan 30 12:17:11: Vi1 VPDN: Set to Async interfaceJan 30 12:17:11: Vi1 VPDN: Clone from Vtemplate 1 filterPPP=0 blockingJan 30 12:17:11: Vi1 VTEMPLATE: Has a new cloneblk vtemplate, now it has vtemplateJan 30 12:17:11: Vi1 VTEMPLATE: ************* CLONE VACCESS1 *****************Jan 30 12:17:11: Vi1 VTEMPLATE: Clone from Virtual-Template1
Verifying L2TP Tunnel Establishment, PPP Negotiations, and Authentication with the Remote Client
Perform this task to verify that the L2TP tunnel has been established and that the tunnel server can perform PPP negotiation and authentication with the remote client.
In this example the steps are performed on the tunnel server, which is performing remote AAA as a tunnel terminator. These steps can also be performed on the NAS when remote AAA is being performed on the NAS as a tunnel initiator for dial-in VPDNs or as a tunnel terminator for dial-out VPDNs.
SUMMARY STEPS
1.
2.
3.
4.
DETAILED STEPS
Step 1
Enter this command to enable privileged EXEC mode. Enter your password if prompted:
Router> enableStep 2
Enter this command on the tunnel server to display PPP negotiation debugging messages.
Step 3
Enter this command on the tunnel server to display PPP authentication debugging messages.
Step 4
Enter this command on the tunnel server to display the contents of the standard system logging message buffer. Observe that the tunnel server receives a PPP Challenge Handshake Authentication Protocol (CHAP) challenge and then sends a PPP CHAP "SUCCESS" to the client.
00:38:50: ppp3 PPP: Received LOGIN Response from AAA = PASS00:38:50: ppp3 PPP: Phase is FORWARDING, Attempting Forward00:38:50: Vi4.1 Tnl/Sn4571/4 L2TP: Session state change from wait-for-service-selection to established00:38:50: Vi4.1 PPP: Phase is AUTHENTICATING, Authenticated User00:38:50: Vi4.1 CHAP: O SUCCESS id 1 len 4After PPP authentication is successful, observe from the debug output that PPP negotiation has started, that the tunnel server has received Link Control Protocol (LCP) IP Control Protocol (IPCP) packets, and that negotiation is successful.
00:38:50: Vi4.1 IPCP: State is Open00:38:50: Vi4.1 IPCP: Install route to 10.1.1.4
Configuring Directed Request Authorization of VPDN Users
Directed request authorization of VPDN users can be configured on the NAS or on the tunnel server. The directed request configuration is performed on the device that ultimately performs the authentication. Directed requests are most commonly configured on the tunnel server.
Perform one of these tasks to enable directed request authorization of VPDN users.
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Configuring Directed Request Authorization of VPDN Users on the Tunnel Server
Perform this task on the tunnel server to configure directed request authorization of VPDN users when the tunnel server performs authentication.
Prerequisites
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SUMMARY STEPS
1.
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or
tacacs-server directed-request [restricted] [no-truncate]5.
DETAILED STEPS
Step 1
enable
Example:Router> enable
Enables privileged EXEC mode.
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Step 2
configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3
ip host {name | tmodem-telephone-number} [tcp-port-number] address1 [address2...address8]
Example:Router(config)# ip host example.com 10.3.3.3
Specifies or modifies the hostname for the network server.
Note
Step 4
radius-server directed-request [restricted]
or
tacacs-server directed-request [restricted] [no-truncate]
Example:Router(config)# radius-server directed-request
or
Router(config)# tacacs-server directed-request
Allows users logging in to a NAS to select a RADIUS server for authentication.
or
Allows users logging in to a NAS to select a TACACS+ server for authentication.
Step 5
vpdn authorize directed-request
Example:Router(config)# vpdn authorize directed-request
Enables VPDN authorization for directed request users.
What to Do Next
You must perform the process in the "Configuring VPDN Tunnel Authentication" section.
Configuring Directed Request Authorization of VPDN Users on the NAS
Perform this task on the NAS to configure directed request authorization of VPDN users when the NAS performs authentication.
Prerequisites
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You must perform the task in the "Configuring Remote AAA for VPDNs" section.
SUMMARY STEPS
1.
2.
3.
4.
or
tacacs-server directed-request [restricted] [no-truncate]5.
DETAILED STEPS
Step 1
enable
Example:Router> enable
Enables privileged EXEC mode.
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Step 2
configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3
ip host {name | tmodem-telephone-number} [tcp-port-number] address1 [address2...address8]
Example:Router(config)# ip host example.com 10.3.3.3
Specifies or modifies the hostname for the network server.
Note
Step 4
radius-server directed-request [restricted]
or
tacacs-server directed-request [restricted] [no-truncate]
Example:Router(config)# radius-server directed-request
or
Router(config)# tacacs-server directed-request
Allows users logging in to a NAS to select a RADIUS server for authentication.
or
Allows users logging in to a NAS to select a TACACS+ server for authentication.
Step 5
vpdn authorize directed-request
Example:Router(config)# vpdn authorize directed-request
Enables VPDN authorization for directed request users.
What to Do Next
You must perform the process in the "Configuring VPDN Tunnel Authentication" section.
Configuring Domain Name Prefix and Suffix Stripping
A single set of stripping rules can be configured globally. An independent set of stripping rules can be configured for each virtual private network (VPN) routing and forwarding (VRF) instance.
Global stripping rules are applied to all usernames, and per-VRF rules are applied only to usernames associated with the specified VRF. If a per-VRF rule is configured, it will take precedence over the global rule for usernames associated with that VRF.
The interactions between the different types of domain stripping configurations are as follows:
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For detailed examples of the interactions between different types of domain stripping configurations, see the "Examples: Configuring Domain Name Prefix and Suffix Stripping" section.
Perform this task on the NAS to configure a set of global or per-VRF stripping rules.
Prerequisites
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SUMMARY STEPS
1.
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3.
or
tacacs-server domain-stripping [right-to-left] [prefix-delimiter character [character2...character7]] [delimiter character [character2...character7]] [vrf vrf-name]4.
or
tacacs-server domain-stripping strip-suffix suffix [vrf vrf-name]DETAILED STEPSWhat to Do Next
For detailed examples of the interactions between different types of domain stripping configurations, see the "Examples: Configuring Domain Name Prefix and Suffix Stripping" section.
You must perform the task in the "Configuring VPDN Tunnel Authentication" section.
Configuring VPDN Tunnel Authentication
VPDN tunnel authentication enables routers to authenticate the other tunnel endpoint before establishing a VPDN tunnel. VPDN tunnel authentication is optional but highly recommended for L2TP, L2TPv3, and PPTP tunnels.
By default, the router will use the hostname as the tunnel name in VPDN tunnel authentication. If a local name is configured under a VPDN group, the router will use the local name when negotiating authentication for tunnels belonging to that VPDN group.
For NAS-initiated VPDN deployments VPDN deployments, tunnel authentication requires that a single shared secret be configured on both the NAS and the tunnel server. For L2TP tunnels, the password can be configured using the hostname, the local name, or the L2TP tunnel password.
For client-initiated VPDN tunneling deployments, tunnel authentication requires that a single shared secret be configured on both the client and the tunnel server. The available authentication configuration options depend on the tunneling protocol being used.
For L2TPv3 client-initiated VPDN tunnels, the shared secret can be configured on the local peer router and the tunnel server in either of these ways:
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For L2TP client-initiated VPDN tunnels, the shared secret can be configured on the tunnel server using the hostname, the local name, or the L2TP tunnel password as described the process documented in this section. The shared secret can be configured on the local peer router in either of these ways:
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For PPTP client-initiated VPDN tunnels, authentication parameters can be configured by using the hostname or the local name as described in the process documented in this section.
To configure VPDN tunnel authentication, you must perform one of the following tasks on the NAS and the tunnel server as required. You need not choose the same method to configure the secret on the NAS and the tunnel server. However, the configured password must be the same on both devices.
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VPDN tunnel authentication is optional for L2TP tunnels. Perform this task on the NAS and the tunnel server if you want to disable VPDN tunnel authentication:
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Prerequisites
AAA must be enabled. See the "Configuring AAA on the NAS and the Tunnel Server" section.
Configuring VPDN Tunnel Authentication Using the Hostname
Perform this task on the NAS or tunnel server to configure VPDN tunnel authentication using the hostname.
SUMMARY STEPS
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DETAILED STEPS
What to Do Next
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Configuring VPDN Tunnel Authentication Using the Local Name
Perform this task on the NAS or tunnel server to configure VPDN tunnel authentication using the local name.
SUMMARY STEPS
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DETAILED STEPS
What to Do Next
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Configuring VPDN Tunnel Authentication Using the L2TP Tunnel Password
Perform this task on the NAS or tunnel server to configure VPDN tunnel authentication using the L2TP tunnel password. This task can be used only for VPDN tunnel authentication of L2TP tunnels.
SUMMARY STEPS
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7.
DETAILED STEPS
What to Do Next
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Disabling VPDN Tunnel Authentication for L2TP Tunnels
Perform this task to disable VPDN tunnel authentication for L2TP tunnels. You must perform this task on both the NAS and the tunnel server to disable VPDN tunnel authentication.
SUMMARY STEPS
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DETAILED STEPS
What to Do Next
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Configuring RADIUS Tunnel Accounting for L2TP VPDNs
The new RADIUS tunnel accounting types are used with the RADIUS accounting attribute Acct-Status-Type (attribute 40), which indicates whether an accounting request marks the beginning of user service (start) or the end (stop).
Perform this task to configure a NAS or tunnel server to send tunnel and tunnel-link accounting records to the remote RADIUS server.
Prerequisites
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Restrictions
RADIUS tunnel accounting is supported only for VPDNs using the L2TP protocol.
SUMMARY STEPS
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3.
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DETAILED STEPS
What to Do Next
You can configure any of the VPDN-specific remote RADIUS AAA attributes.
Configuring Authentication of L2TP Tunnels at the Tunnel Terminator Remote RADIUS AAA Server
For L2TP tunnels, you can configure the device that terminates the VPDN tunnel to perform remote RADIUS AAA. A remote RADIUS AAA server can be used to perform VPDN tunnel authentication on the tunnel terminator as follows:
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Perform this task on the remote RADIUS AAA server to configure the RADIUS server to authenticate VPDN tunnels at the device that terminates the tunnel.
Prerequisites
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Restrictions
This task applies only when the device that terminates the VPDN tunnel is performing remote RADIUS AAA. To configure the tunnel terminator to perform remote RADIUS AAA, perform the task in the "Configuring the Tunnel Terminator for Remote RADIUS AAA for L2TP Tunnels" section.
SUMMARY STEPS
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DETAILED STEPS
Step 1
service type = Outbound
Example:service type = Outbound
Specifies the service type.
Step 2
tunnel-type = protocol
Example:tunnel-type = l2tp
Specifies the tunneling protocol.
Note
Step 3
Cisco:Cisco-Avpair = vpdn:dout-dialer = NAS-dialer-number
Example:Cisco:Cisco-Avpair = vpdn:dout-dialer = 2
Specifies which dialer to use on the NAS for dial-out configuration.
Note
Step 4
Cisco:Cisco-Avpair = vpdn:vpdn-vtemplate = vtemplate-number
Example:Cisco:Cisco-Avpair = vpdn:vpdn-vtemplate = 1
Specifies the virtual template number to use on the tunnel server for dial-in configuration.
Note
Note
What to Do Next
You can configure any of the other VPDN-specific remote RADIUS AAA attributes.
Configuring Tunnel Assignments on the NAS Remote RADIUS AAA Server
Tunnel assignments allow the grouping of users from different per-user or domain RADIUS profiles into the same active tunnel. This functionality prevents the establishment of duplicate tunnels when the tunnel type, tunnel endpoints, and tunnel assignment ID are identical.
Perform this task on the NAS remote RADIUS AAA server for each user and domain that you want to group into the same tunnel.
Prerequisites
The RADIUS server must be configured for AAA.
SUMMARY STEPS
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user.domain.com Password = "secret" Service-Type = Outbound
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DETAILED STEPS
What to Do Next
You can configure any of the other VPDN-specific remote RADIUS AAA attributes.
Configuring Secure Tunnel Authentication Names on the NAS Remote RADIUS AAA Server
The NAS AAA server can be configured with authentication names other than the default names for the NAS and the NAS AAA server, providing a higher level of security during VPDN tunnel establishment.
RADIUS tunnel authentication name attributes allows you to specify a name other than the default name for the tunnel initiator and for the tunnel terminator. These authentication names are specified using RADIUS tunnel attributes 90 and 91.
Perform this task on the remote RADIUS AAA server. This task applies to NAS-initiated tunnels using either L2TP or L2F.
Prerequisites
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SUMMARY STEPS
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user.example.com Password = "secret" Service-Type = Outbound
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DETAILED STEPSWhat to Do Next
You can configure any of the other VPDN-specific remote RADIUS AAA attributes.
Configuring L2TP Forwarding of PPPoE Tagging Information
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Configuring L2TP Forwarding of PPPoE Tagging Information
On the LAC, perform these steps to configure L2TP Forwarding of PPPoE Tagging Information to populate the circuit-id tag in the nas-port-id attribute and the remote-id tag in the calling-station-id attribute on the LNS.
SUMMARY STEPS
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DETAILED STEPS
Overriding L2TP Forwarding of PPPoE Tag Information
You can configure the L2TP Forwarding of PPPoE Tagging Information feature to override the following VSA:
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Overriding nas-port VSA with circuit-id
To override the population of the circuit-id tag in the nas-port-id attribute on the LNS, perform these steps on the LNS.
SUMMARY STEPS
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DETAILED STEPS
Overriding calling-station-id VSA with remote-id
To override the calling-station-id VSA with the remote-id on the LNS, perform these steps:
SUMMARY STEPS
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DETAILED STEPS
Removing L2TP Forwarding of PPPoE Tag Information
Outgoing PADO and PADS packets will have the DSLAM-inserted Vendor-Specific Line-Id tag, and DSLAM must strip the Circuit-Id tag from the packets. If the DSLAM cannot strip the tag, the BRAS must remove it before sending out the packets. This task is accomplished through configuration of the vendor-tag remote-id strip command under BBA group configuration mode.
SUMMARY STEPS
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DETAILED STEPS
Displaying the Session Activity Log
When the radius-server attribute nas-port format d global configuration command is added to the PPPoE Circuit-Id Tag Processing feature configuration on the BRAS (see the "Examples: Configuring the VPDN Tunnel Authorization Search Order" section for an example), the report from the debug radius privileged EXEC command will include information about the incoming access interface, where discovery frames are received, and about the session being established in PPPoE extended NAS-Port format (format d).
Step 1
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Note
Router# debug radius02:10:49: RADIUS(0000003F): Config NAS IP: 0.0.0.002:10:49: RADIUS/ENCODE(0000003F): acct_session_id: 7902:10:49: RADIUS(0000003F): sending02:10:49: RADIUS/ENCODE: Best Local IP-Address 10.0.58.141 for Radius-Server 172.20.164.14302:10:49: RADIUS(0000003F): Send Access-Request to 172.20.164.143:1645 id 1645/65, len 9802:10:49: RADIUS: authenticator 1C 9E B0 A2 82 51 C1 79 - FE 24 F4 D1 2F 84 F5 7902:10:49: RADIUS: Framed-Protocol [7] 6 PPP [1]02:10:49: RADIUS: User-Name [1] 7 "peer1"02:10:49: RADIUS: CHAP-Password [3] 19 *02:10:49: RADIUS: NAS-Port-Type [61] 6 Ethernet [15]02:10:49: RADIUS: NAS-Port [5] 6 20002:10:49: RADIUS: NAS-Port-Id [87] 22 "FastEthernet6/0.200:"02:10:49: RADIUS: Service-Type [6] 6 Framed [2]02:10:49: RADIUS: NAS-IP-Address [4] 6 10.0.58.14102:10:49: RADIUS: Received from id 1645/65 172.20.164.143:1645, Access-Accept, len 32 02:10:49: RADIUS: authenticator 06 45 84 1B 27 1F A5 C3 - C3 C9 69 6E B9 C0 6F 9402:10:49: RADIUS: Service-Type [6] 6 Framed [2]02:10:49: RADIUS: Framed-Protocol [7] 6 PPP [1]02:10:49: RADIUS(0000003F): Received from id 1645/6502:10:49: [62]PPPoE 65: State LCP_NEGOTIATION Event PPP_LOCAL02:10:49: PPPoE 65/SB: Sent vtemplate request on base Vi202:10:49: [62]PPPoE 65: State VACCESS_REQUESTED Event VA_RESP02:10:49: [62]PPPoE 65: Vi2.1 interface obtained02:10:49: [62]PPPoE 65: State PTA_BINDING Event STAT_BIND02:10:49: [62]PPPoE 65: data path set to Virtual Acess02:10:49: [62]PPPoE 65: Connected PTA02:10:49: [62]PPPoE 65: AAA get dynamic attrs02:10:49: [62]PPPoE 65: AAA get dynamic attrs02:10:49: RADIUS/ENCODE(0000003F):Orig. component type = PPoE02:10:49: RADIUS/ENCODE(0000003F): Acct-session-id pre-pended with Nas Port = 0/0/0/20002:10:49: RADIUS(0000003F): Config NAS IP: 0.0.0.002:10:49: RADIUS(0000003F): sending02:10:49: RADIUS/ENCODE: Best Local IP-Address 10.0.58.141 for Radius-Server 172.20.164.14302:10:49: RADIUS(0000003F): Send Accounting-Request to 172.20.164.143:1646 id 1 646/42, len 11702:10:49: RADIUS: authenticator 57 24 38 1A A3 09 62 42 - 55 2F 41 71 38 E1 CC 2402:10:49: RADIUS: Acct-Session-Id [44] 20 "0/0/0/200_0000004F"02:10:49: RADIUS: Framed-Protocol [7] 6 PPP [1]02:10:49: RADIUS: User-Name [1] 7 "peer1"02:10:49: RADIUS: Acct-Authentic [45] 6 RADIUS [1]02:10:49: RADIUS: Acct-Status-Type [40] 6 Start [1]02:10:49: RADIUS: NAS-Port-Type [61] 6 Ethernet [15]02:10:49: RADIUS: NAS-Port [5] 6 20002:10:49: RADIUS: NAS-Port-Id [87] 22 "FastEthernet6/0.200:"02:10:49: RADIUS: Service-Type [6] 6 Framed [2]02:10:49: RADIUS: NAS-IP-Address [4] 6 10.0.58.14102:10:49: RADIUS: Acct-Delay-Time [41] 6 002:10:49: RADIUS: Received from id 1646/42 172.20.164.143:1646, Accounting-resp onse, len 2002:10:49: RADIUS: authenticator 34 84 7E B2 F4 40 B2 7C - C5 B2 4E 98 78 03 8B C0
Configuring L2TP Override Forwarding rx-speed and tx-speed Values Received from PPPoE
By default, L2TP obtains the receive-speed (rx-speed) and transmit-speed (tx-speed) values from PPPoE and sends the values to LNS. To override L2TP forwarding of the rx-speed and tx-speed values received from PPPoE, the rx-speed and the tx-speed values should be configured in the RADIUS server, or by using the l2tp rx-speed and l2tp tx-speed commands in VPDN group configuration or VPDN template configuration mode. The speed values are configured in kbps.
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Configuring rx-speed and tx-speed Values When the RADIUS Server Is Not Used
When the RADIUS server is not used, the rx-speed and the tx-speed values can be configured in VPDN group configuration or VPDN template configuration mode. The rx-speed and tx-speed values configured in VPDN group configuration mode are specific to the tunnel and are sent to all sessions under the tunnel.
Perform this task to configure rx-speed and tx-speed values in VPDN group configuration or VPDN template configuration mode when the RADIUS server is not used.
SUMMARY STEPS
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vpdn-template name5.
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DETAILED STEPS
Configuring rx-speed and tx-speed Values on the RADIUS Server
You can configure the rx-speed and tx-speed values on the RADIUS server by:
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The values configured for rx-speed and tx-speed are session oriented. L2TP stores the rx-speed and tx-speed values for every session by using the vpdn-authen-before-forward command configured on LAC.
The steps for configuring the default rx-speed and tx-speed values on the RADIUS server are the same as configuring the rx-speed and tx-speed values when the RADIUS server is not used. For configuring rx-speed and tx-speed values on the RADIUS server, see the "Configuring rx-speed and tx-speed Values When the RADIUS Server Is Not Used" section.
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Configuring rx-speed and tx-speed Values from ANCP on the RADIUS Server
ANCP sends the upstream and downstream values to L2TP. The upstream value is the rx-speed value and the downstream value is the tx-speed value.
Perform this task on the RADIUS server to configure rx-speed and tx-speed values from ANCP.
Prerequisites
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SUMMARY STEPS
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vpdn-template name5.
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DETAILED STEPS
Configuring rx-speed and tx-speed Values from RAM-min on the RADIUS Server
Perform this task on the RADIUS server to configure the rx-speed and tx-speed values from RAM-min.
Prerequisites
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SUMMARY STEPS
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vpdn-template name5.
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DETAILED STEPS
Configuring LNS Address Checking
To allow a LAC to check the IP address of the LNS sending traffic to it during the setup of an L2TP tunnel, thus providing a check for uplink and downlink traffic arriving from different interfaces, follow this procedure.
SUMMARY STEPS
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Configuring Modified LNS Dead-Cache Handling
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Identifying an LNS in a Dead-Cache State
With the Modified LNS Dead-Cache Handling feature, you can use the show vpdn dead-cache command to display the status of an LNS in an LSG on a LAC and determine if an LNS is not responding (dead-cache state). The show vpdn dead-cache command displays the IP address of the nonresponding LNS, and a time entry showing how long the LNS has been down.
This procedure shows how to use the show vpdn dead-cache command to display the status of an LNS to determine if it is in a dead-cache state. An LNS in a dead-cache state cannot establish new sessions or calls.
SUMMARY STEPS
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DETAILED STEPS
Clearing an LNS in a Dead-Cache State
With the Modified LNS Dead-Cache Handling feature, you can use the clear vpdn dead-cache command to clear an LNS entry in the dead-cache based on the IP address of the LNS, clear all LNS dead-cache states in a VPDN group, or clear all dead-cache LNS entries. If you clear an LNS based on its IP address, and the LNS is associated with more than one VPDN group, the LNS is cleared in all the associated VPDN groups.
This procedure shows how to clear an LNS in a dead-cache state. Once an entry clears from the dead-cache state, the entry is available for new session establishments and calls.
Prerequisites
Perform this procedure on the LAC.
SUMMARY STEPS
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DETAILED STEPS
Generating an SNMP Event for a Dead-Cache Entry
If you are a manager responsible for a large number of devices, and each device has a large number of objects, it is impractical for you to poll or request information from every object on every device. SNMP trap-directed notification alerts you without solicitation, by sending a message known as a trap of the event. After you receive the event, you can display it and can choose to take an appropriate action based on the event.
To generate an SNMP event when an LNS exits or enters the dead-cache state, follow this procedure.
SUMMARY STEPS
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DETAILED STEPS
Generating a Syslog Event for a Dead-Cache Entry
To view a syslog event when an LNS is added, deleted, or cleared from a dead-cache state, configure the vpdn logging dead-cache command. You can use syslog events to help troubleshoot networks.
Table 3 summarizes the syslog messages generated by using the vpdn logging dead-cache command.
To generate a syslog event when an LNS enters or exits the dead-cache state, follow this procedure.
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Configuration Examples for AAA for VPDNs
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Examples: Configuring the VPDN Tunnel Authorization Search Order
The following configuration example enables VPDN and configures a tunnel authorization search order that will be used instead of the default search order of DNIS number, then domain.
vpdn enablevpdn search-order domain dnisThe following example enables VPDN and multihop, and configures a tunnel authorization search order of multihop hostname first, then domain, then DNIS number. This configuration is used only on a tunnel switch.
vpdn enablevpdn multihopvpdn search-order multihop-hostname domain dnisExamples: Configuring per-User VPDN on the NAS
The following example enables VPDN and configures global per-user VPDN on the NAS for all dial-in VPDN tunnels. The first time the NAS contacts the remote RADIUS AAA server, the entire structured username will be sent rather than just the domain name or DNIS number.
vpdn enablevpdn authen-before-forwardThe following example enables VPDN and configures per-user VPDN on the NAS for dial-in VPDN tunnels belonging to the VPDN group named cisco1. The first time the NAS contacts the remote RADIUS AAA server, the entire structured username will be sent rather than just the domain name or DNIS number.
vpdn enablevpdn-group cisco1request-dialinprotocol l2tpexitauthen-before-forwardExamples: Configuring AAA on the NAS and the Tunnel Server
The following example enables VPDN and local authentication and authorization on the NAS or the tunnel server:
vpdn enable!aaa new-modelaaa authentication login default localaaa authentication ppp default localaaa authorization network default localThe following examples enables VPDN and configures the NAS and the tunnel server for dial-in VPDN tunnels when remote RADIUS AAA authentication occurs at the NAS:
NAS Configuration
vpdn enable!aaa new-modelaaa authentication login default radiusaaa authentication ppp default radiusaaa authorization network default radiusaaa accounting network default start-stop radiusradius-server host 10.1.1.1 auth-port 1939 acct-port 1443vpdn aaa untaggedTunnel Server Configuration
vpdn enable!aaa new-modelaaa authentication login default radiusaaa authentication ppp default radiusaaa authorization network default radiusaaa accounting network default start-stop radiusvpdn aaa attribute nas-ip-address vpdn-nasvpdn aaa untaggedThe Basic TACACS+ Configuration Example document provides a basic configuration of TACACS+ for user dialup authentication to a NAS.
Examples: Configuring Remote AAA for VPDNs on the L2TP Tunnel Terminator
The following example enables VPDN and configures the NAS and the tunnel server for dial-in VPDN tunnels with remote RADIUS AAA authentication occurring at the tunnel server. A sample RADIUS user profile for the remote RADIUS AAA server is also shown.
NAS Configuration
vpdn enable!aaa new-modelaaa authentication login default radiusaaa authentication ppp default radiusaaa authorization network default radiusaaa accounting network default start-stop radiusradius-server host 10.1.1.1 auth-port 1939 acct-port 1443vpdn aaa untaggedTunnel Server Configuration
vpdn enable!aaa new-modelaaa authentication login default radiusaaa authentication ppp default radiusaaa authorization network default mymethodlist group myvpdngroupradius-server host 10.2.2.2 auth-port 1939 acct-port 1443aaa group server radius myvpdngroupserver 10.2.2.2 auth-port 1939 acct-port 1443!vpdn tunnel authorization network mymethodlistvpdn tunnel authorization virtual-template 1RADIUS User Profile
csidtw13 Password = "cisco"Service-Type = Outbound,Tunnel-Type = :0:L2TP,Tunnel-Medium-Type = :0:IP,Tunnel-Client-Auth-ID = :0:"csidtw13",Tunnel-Password = :0:"cisco"Cisco:Cisco-Avpair = "vpdn:vpdn-vtemplate=1"Examples: Configuring Directed Request Authorization of VPDN Users
The following example enables VPDN and configures remote RADIUS AAA with VPDN authentication of directed request users on the tunnel server:
vpdn enable!aaa new-modelaaa authentication login default radiusaaa authentication ppp default radiusaaa authorization network default mymethodlist group myvpdngroupradius-server host 10.3.3.3 auth-port 1939 acct-port 1443aaa group server radius myvpdngroupserver 10.3.3.3 auth-port 1939 acct-port 1443!ip host example.com 10.3.3.3radius-server directed-requestvpdn authorize directed-requestThe following example enables VPDN and configures per-user VPDN, remote TACACS+ AAA, and VPDN authentication of directed request users on the NAS:
vpdn enablevpdn-group 1request-dialinprotocol l2tpdomain example.com!initiate-to 10.3.3.3local name local1authen-before-forward!aaa new-modelaaa authentication login default tacacsaaa authentication ppp default tacacsaaa authorization network default mymethod group mygroupradius-server host 10.4.4.4 auth-port 1201 acct-port 1450aaa group server tacacs mygroupserver 10.3.3.3 auth-port 1201 acct-port 1450!ip host example.com 10.3.3.3radius-server directed-requestvpdn authorize directed-requestExamples: Configuring Domain Name Prefix and Suffix Stripping
The following example configures the router to parse the username from right to left and sets the valid suffix delimiter characters as @, \, and $. If the full username is cisco/user@cisco.com$cisco.net, the username "cisco/user@cisco.com" will be forwarded to the RADIUS server because the $ character is the first valid delimiter encountered by the NAS when parsing the username from right to left.
radius-server domain-stripping right-to-left delimiter @\$The following example configures the router to strip the domain name from usernames only for users associated with the VRF instance named abc. The default suffix delimiter @ will be used for generic suffix stripping.
radius-server domain-stripping vrf abcThe following example enables prefix stripping using the character / as the prefix delimiter. The default suffix delimiter character @ will be used for generic suffix stripping. If the full username is cisco/user@cisco.com, the username "user" will be forwarded to the TACACS+ server.
tacacs-server domain-stripping prefix-delimiter /The following example enables prefix stripping, specifies the character / as the prefix delimiter, and specifies the character # as the suffix delimiter. If the full username is cisco/user@cisco.com#cisco.net, the username "user@cisco.com" will be forwarded to the RADIUS server.
radius-server domain-stripping prefix-delimiter / delimiter #The following example enables prefix stripping, configures the character / as the prefix delimiter, configures the characters $, @, and # as suffix delimiters, and configures per-suffix stripping of the suffix cisco.com. If the full username is cisco/user@cisco.com, the username "user" will be forwarded to the TACACS+ server. If the full username is cisco/user@cisco.com#cisco.com, the username "user@cisco.com" will be forwarded.
tacacs-server domain-stripping prefix-delimiter / delimiter $@#tacacs-server domain-stripping strip-suffix cisco.comThe following example configures the router to parse the username from right to left and enables suffix stripping for usernames with the suffix cisco.com. If the full username is cisco/user@cisco.net@cisco.com, the username "cisco/user@cisco.net" will be forwarded to the RADIUS server. If the full username is cisco/user@cisco.com@cisco.net, the full username will be forwarded.
radius-server domain-stripping right-to-leftradius-server domain-stripping strip-suffix cisco.comThe following example configures a set of global stripping rules that will strip the suffix cisco.com using the delimiter @, and a different set of stripping rules for usernames associated with the VRF named myvrf:
radius-server domain-stripping strip-suffix cisco.com!radius-server domain-stripping prefix-delimiter # vrf myvrfradius-server domain-stripping strip-suffix cisco.net vrf myvrfExamples: Configuring VPDN Tunnel Authentication
The following example configures VPDN tunnel authentication using the hostname on a NAS and the local name on the tunnel server. Note that the secret password configured for each device matches.
NAS Configuration
hostname NAS1username tunnelserver1 password supersecretTunnel Server Configuration
vpdn-group 1local name tunnelserver1exitusername NAS1 password supersecretThe following example configures VPDN tunnel authentication using the local name on the NAS and the L2TP tunnel password on the tunnel server. Note that the secret password configured for each device matches.
NAS Configuration
vpdn-group 2local name NAS6!username tunnelserver12 password verysecretTunnel Server Configuration
vpdn-group 4l2tp tunnel password verysecretlocal name tunnelserver12exitusername NAS6 password verysecretThe following example configures VPDN tunnel authentication using the L2TP tunnel password on both the NAS and the tunnel server. Note that the secret password configured for each device matches.
NAS Configuration
vpdn-group l2tpl2tp tunnel password rathersecretTunnel Server Configuration
vpdn-group 46l2tp tunnel password rathersecretExample: Configuring RADIUS Tunnel Accounting on a NAS
The following example configures a NAS for remote AAA, configures a dial-in VPDN deployment, and enables the sending of tunnel and tunnel-link accounting records to the RADIUS server:
aaa new-model!aaa authentication ppp default group radiusaaa authorization network default localaaa accounting network m1 start-stop group radiusaaa accounting network m2 stop-only group radiusaaa session-id commonenable secret 5 $1$IDjH$iL7puCja1RMlyOM.JAeuf/enable password secret!username ISP-LAC password 0 tunnelpass!resource-pool disable!ip subnet-zeroip cefno ip domain-lookupip host myhost 172.16.1.129!vpdn enablevpdn tunnel accounting network m1vpdn session accounting network m1vpdn search-order domain dnis!vpdn-group 1request-dialinprotocol l2tpdomain cisco.cominitiate-to ip 10.1.26.71local name ISP-LAC!isdn switch-type primary-5ess!fax interface-type fax-mailmta receive maximum-recipients 0!controller T1 7/4framing esflinecode b8zspri-group timeslots 1-24!interface GigabitEthernet0/0/0ip address 10.1.27.74 255.255.255.0no ip mroute-cacheduplex halfspeed autono cdp enable!interface GigabitEthernet0/1/0no ip addressno ip mroute-cacheshutdownduplex autospeed autono cdp enable!interface Serial7/4:23ip address 10.0.0.2 255.255.255.0encapsulation pppdialer string 2000dialer-group 1isdn switch-type primary-5essppp authentication chap!interface Group-Async0no ip addressshutdowngroup-range 1/00 3/107!ip default-gateway 10.1.27.254ip classlessip route 0.0.0.0 0.0.0.0 10.1.27.254no ip http serverip pim bidir-enable!dialer-list 1 protocol ip permitno cdp run!radius-server host 172.19.192.26 auth-port 1645 acct-port 1646 key rad123radius-server retransmit 3call rsvp-syncExample: Configuring RADIUS Tunnel Accounting on a Tunnel Server
The following example configures a tunnel server for remote AAA, configures a dial-in VPDN deployment, and enables the sending of tunnel and tunnel-link accounting records to the RADIUS server:
aaa new-model!aaa accounting network m1 start-stop group radiusaaa accounting network m2 stop-only group radiusaaa session-id commonenable secret 5 $1$ftf.$wE6Q5Yv6hmQiwL9pizPCg1!username ENT_LNS password 0 tunnelpassusername user1@cisco.com password 0 labusername user2@cisco.com password 0 lab!spe 1/0 1/7firmware location system:/ucode/mica_port_firmware!spe 2/0 2/9firmware location system:/ucode/mica_port_firmware!resource-pool disableclock timezone est 2!ip subnet-zerono ip domain-lookupip host CALLGEN-SECURITY-V2 10.24.80.28 10.47.0.0ip host myhost 172.16.1.129!vpdn enablevpdn tunnel accounting network m1vpdn session accounting network m1!vpdn-group 1accept-dialinprotocol l2tpvirtual-template 1terminate-from hostname ISP_NASlocal name ENT_TS!isdn switch-type primary-5ess!fax interface-type modemmta receive maximum-recipients 0!interface Loopback0ip address 10.0.0.101 255.255.255.0!interface Loopback1ip address 10.0.0.201 255.255.255.0!interface Ethernet0ip address 10.1.26.71 255.255.255.0no ip mroute-cacheno cdp enable!interface Virtual-Template1ip unnumbered Loopback0peer default ip address pool vpdn-pool1ppp authentication chap!interface Virtual-Template2ip unnumbered Loopback1peer default ip address pool vpdn-pool2ppp authentication chap!interface FastEthernet0no ip addressno ip mroute-cacheshutdownduplex autospeed autono cdp enable!ip local pool vpdn-pool1 10.0.0.2 10.0.0.200ip local pool vpdn-pool2 10.0.0.1 10.0.0.100ip default-gateway 10.1.26.254ip classlessip route 0.0.0.0 0.0.0.0 10.1.26.254ip route 10.1.1.2 255.255.255.255 10.1.26.254no ip http serverip pim bidir-enable!dialer-list 1 protocol ip permitno cdp run!radius-server host 172.16.192.80 auth-port 1645 acct-port 1646 key rad123radius-server retransmit 3call rsvp-syncExample: Configuring Tunnel Assignments on the NAS RADIUS AAA Server
The following examples configure the RADIUS server to group sessions in a tunnel:
Per-User Configuration
user@cisco.com Password = "cisco" Service-Type = Outbound,tunnel-type = :1:L2TP,tunnel-server-endpoint = :1:"10.14.10.54",tunnel-assignment-Id = :1:"router"client@cisco.com Password = "cisco" Service-Type = Outbound,tunnel-type = :1:L2TP,tunnel-server-endpoint = :1:"10.14.10.54",tunnel-assignment-Id = :1:"router"Domain Configuration
eng.cisco.com Password = "cisco" Service-Type = Outbound,tunnel-type = :1:L2TP,tunnel-server-endpoint = :1:"10.14.10.54",tunnel-assignment-Id = :1:"router"sales.cisco.com Password = "cisco" Service-Type = Outbound,tunnel-type = :1:L2TP,tunnel-server-endpoint = :1:"10.14.10.54",tunnel-assignment-Id = :1:"router"Examples: Configuring rx-speed and tx-speed Values
The following example shows how to configure average rate traffic shaping value for the default class in policy-map class configuration mode:
interface GigabitEthernet3/1/0.30880387encapsulation dot1Q 3088 second-dot1q 20ancp neighbor name ancp-neighbor id 0016.fa11.0488 client-ID "12.124.234.132/0.0.0.0 eth 3/4/1.32"pppoe enable group test2service-policy output speed:ether:22000:1200:06/0!policy-map speed:ether:22000:1200:06/0class class-defaultshape average 10281000 !10,281 Mbps is so-called Rate Adaptive Mode (RAM) MIN value!!The following example shows how to configure rx-speed and tx-speed values for an ATM interface when the rx-speed and tx-speed values, including 0, 0, are not configured in the RADIUS server. The average rate traffic shaping value is configured for the Ethernet interface. If the average rate traffic shaping value for the default class in policy-map class configuration mode is not configured, the rx-speed and tx-speed values specified in the l2tp rx-speed and l2tp tx-speed commands are configured for the ATM interface.
Interface ATM 1/0/4.2vpdn-template 2l2tp rx-speed ram-min 8000l2tp tx-speed ram-min 8000The following example shows how to configure rx-speed and tx-speed values for an Ethernet interface when the rx-speed and tx-speed values, including 0, 0, are not configured in the RADIUS server. The rx-speed and tx-speed values configured for ANCP is configured for the Ethernet interface. If the rx-speed and tx-speed values are not configured for ANCP, the rx-speed and tx-speed values specified in the l2tp rx-speed and l2tp tx-speed commands are configured for the Ethernet interface.
Interface Ethernet 3/0/1.3vpdn-template 1l2tp rx-speed ancp 15000l2tp tx-speed ancp 15000Example: Configuring Secure Authentication Names
The following is an example of a RADIUS user profile that includes RADIUS tunneling attributes 90 and 91. This entry supports two tunnels, one for L2F and the other for L2TP. The tag entries with :1 support L2F tunnels, and the tag entries with :2 support L2TP tunnels.
cisco.com Password = "cisco", Service-Type = OutboundService-Type = Outbound,Tunnel-Type = :1:L2F,Tunnel-Medium-Type = :1:IP,Tunnel-Client-Endpoint = :1:"10.0.0.2",Tunnel-Server-Endpoint = :1:"10.0.0.3",Tunnel-Client-Auth-Id = :1:"l2f-cli-auth-id",Tunnel-Server-Auth-Id = :1:"l2f-svr-auth-id",Tunnel-Assignment-Id = :1:"l2f-assignment-id",Cisco-Avpair = "vpdn:nas-password=l2f-cli-pass",Cisco-Avpair = "vpdn:gw-password=l2f-svr-pass",Tunnel-Preference = :1:1,Tunnel-Type = :2:L2TP,Tunnel-Medium-Type = :2:IP,Tunnel-Client-Endpoint = :2:"10.0.0.2",Tunnel-Server-Endpoint = :2:"10.0.0.3",Tunnel-Client-Auth-Id = :2:"l2tp-cli-auth-id",Tunnel-Server-Auth-Id = :2:"l2tp-svr-auth-id",Tunnel-Assignment-Id = :2:"l2tp-assignment-id",Cisco-Avpair = "vpdn:l2tp-tunnel-password=l2tp-tnl-pass",Tunnel-Preference = :2:2Examples: Configuring LNS Address Checking
The following shows an example configuration for the client router.
hostname Client!enable password example!no aaa new-model!vpdn enable!bba-group pppoe 1virtual-template 1!interface <interface toward LAC>pppoe enable group 1!interface Virtual-Template 1ip unnumbered <interface>ppp pap sent-username@example.com!endThe following shows an example configuration for the LAC.
hostname LAC!enable password example!no aaa new-model!vpdn enable!vpdn-group 1request-dialinprotocol l2tpdomain example.cominitiate-to ip <lns 1 IP address>l2tp tunnel password 0 example!bba-group pppoe 1virtual-template 1!interface Virtual-Template 1no ip addressppp authentication pap!interface <interface>pppoe enable group 1!endThe following shows an example configuration for the LNS 1.
hostname LNS1!enable password example!aaa authentication ppp default local!vpdn enable!vpdn-group 1!Default L2TP VPDN groupaccept-dialinprotocol l2tpvirtual-template 1l2tp tunnel password 0 example!vpdn-group 2request-dialinprotocol l2tpdomain example.cominitiate-to ip <lns 2 IP address>l2tp tunnel password 0 example!interface Virtual-Template 1ip unnumbered <interface>ppp authentication pap!endExamples: Configuring Modified LNS Dead-Cache Handling
The following show an example configuration from the show vpdn dead-cache all command:
Router# show vpdn dead-cache allvpdn-group ip address down timeexampleA 192.168.2.2 00:10:23exampleB 192.168.4.2 00:10:16exampleB 192.168.4.3 00:10:15exampleB 192.168.4.4 00:10:12The following shows an example configuration to clear an LNS, based on its IP address, from the dead-cache state.
Router# clear vpdn dead-cache ip-address 192.168.4.4Router#*Sept. 30 22:58:32 %VPDN-6-VPDN_DEADCACHE_CHANGE: LSG dead cache entry 192.168.4.4 clearedRouter# show vpdn dead-cache allvpdn-group ip address down timeexampleA 192.168.2.2 00:10:28exampleB 192.168.4.2 00:10:21exampleB 192.168.4.3 00:10:20The following shows an example configuration to clear an LNS group from the dead-cache state.
Router# clear vpdn dead-cache group exampleBRouter#*Sept. 30 22:58:32 %VPDN-6-VPDN_DEADCACHE_CHANGE: LSG dead cache entry 192.168.4.2 cleared*Sept. 30 22:58:32 %VPDN-6-VPDN_DEADCACHE_CHANGE: LSG dead cache entry 192.168.4.3 clearedRouter# show vpdn dead-cache allvpdn-group ip address down timeexampleA 192.168.2.2 00:10:31Where to Go Next
Depending on the type of VPDN deployment you are configuring, you should perform the tasks in one of these modules:
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Additional References
Related Documents
Cisco IOS commands
VPDN technology overview
"VPDN Technology Overview" module
VPDN commands: complete command syntax, command mode, defaults, usage guidelines, and examples
Information about configuring AAA
"Authentication, Authorization, and Accounting (AAA)" module
Layer 2 Tunnel Protocol
Information about configuring RADIUS and TACACS
"Security Server Protocols" module
Security commands: complete command syntax, command mode, defaults, usage guidelines, and examples
Dial Technologies commands: complete command syntax, command mode, defaults, usage guidelines, and examples
Standards
MIBs
RFCs
RFC 2516
A Method for Transmitting PPP Over Ethernet (PPPoE)
RFC 2867
RADIUS Accounting Modifications for Tunnel Protocol Support
RFC 2868
RADIUS Tunnel Authentication Attributes
Technical Assistance
Feature Information for AAA for VPDNs
Table 4 lists the features in this module and provides links to specific configuration information.
Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Note
Table 4 Feature Information for AAA for VPDNs
Configurable Domain Name Prefix and Suffix Stripping for the RADIUS server
Cisco IOS XE Release 2.1
This feature allows the NAS to be configured to strip prefixes, suffixes, or both from the full username. The reformatted username is then forwarded to the remote AAA server.
The following sections provide information about this feature:
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The following command was introduced or modified by this feature: radius-server domain-stripping.
RADIUS Attribute 82: Tunnel Assignment ID
Cisco IOS XE Release 2.1
This feature allows the L2TP NAS to group users from different per-user or domain RADIUS profiles into the same active tunnel if the tunnel endpoints, tunnel type, and Tunnel-Assignment-ID are identical.
The following sections provide information about this feature:
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No commands were introduced or modified by this feature.
RADIUS Tunnel Attribute Extensions
Cisco IOS XE Release 2.1
This feature introduces RADIUS attribute 90 and RADIUS attribute 91. Both attributes help support the provision of compulsory tunneling in VPDNs by allowing the user to specify authentication names for the NAS and the RADIUS server.
The following sections provide information about this feature:
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No commands were introduced or modified by this feature.
RFC-2867 RADIUS Tunnel Accounting
Cisco IOS XE Release 2.1
This feature introduces six new RADIUS accounting types that are used with the RADIUS accounting attribute Acct-Status-Type (attribute 40), which indicates whether an accounting request marks the beginning of user service (start) or the end (stop).
The following sections provide information about this feature:
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The following commands were introduced or modified by this feature: aaa accounting, vpdn session accounting network, vpdn tunnel accounting network.
Tunnel Authentication via RADIUS on Tunnel Terminator
Cisco IOS XE Release 2.1
This feature allows the L2TP tunnel server to perform remote authentication and authorization with RADIUS on incoming L2TP NAS dial-in connection requests. This feature also allows the L2TP NAS to perform remote authentication and authorization with RADIUS on incoming L2TP tunnel server dial-out connection requests.
The following sections provide information about this feature:
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The following commands were introduced by this feature: vpdn tunnel authorization network, vpdn tunnel authorization password, vpdn tunnel authorization virtual-template.
L2TP Forwarding of PPPoE Tagging Information
Cisco IOS XE Release 2.4
This feature was introduced on Cisco ASR 1000 Series Routers.
LNS Address Checking
Cisco IOS XE Release 2.4
This feature allows an LAC, which is receiving data from a LNS, to check the IP address of the LNS prior to establishing an L2TP tunnel.
The following sections provide information about this feature:
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The following command was introduced by this feature: l2tp security ip address-check.
Modified LNS Dead-Cache Handling
Cisco IOS XE Release 2.4
This feature displays and clears (restarts) any LNS entry in a dead-cache (DOWN) state.
The following sections provide information about this feature:
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The following commands were introduced by this feature: clear vpdn dead-cache, show vpdn dead-cache.
The following commands were modified by this feature: snmp-server enable traps, vpdn logging.
Configurable Domain Name Prefix and Suffix Stripping for the TACACS+ server
Cisco IOS XE Release 2.5
This feature allows the NAS to be configured to strip prefixes, suffixes, or both from the full username. The reformatted username is then forwarded to the remote AAA server.
The following sections provide information about this feature:
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The following command was introduced or modified by this feature: tacacs-server domain-stripping.
ANCP values configuration support on LNS
Cisco IOS XE Release 3.2S
This feature allows L2TP to send the rx-speed and tx-speed values configured in VPDN group configuration or VPDN template configuration mode, or the rx-speed and the tx-speed values configured on the RADIUS server, to LNS.
The following sections provide information about this feature:
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The following commands were introduced by this feature: l2tp rx-speed, l2tp tx-speed.
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Any Internet Protocol (IP) addresses and phone numbers used in this document are not intended to be actual addresses and phone numbers. Any examples, command display output, network topology diagrams, and other figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses or phone numbers in illustrative content is unintentional and coincidental.
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