Remote Access VPN Does Not Work When RADIUS Authentication and Authorization is Configured

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Updated:April 11, 2014

Document ID:117622

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Introduction

Prerequisites

Requirements

Components Used

Problem

Solution

Local Authorization Versus RADIUS Authorization

Working Configuration

Router Configuration

RADIUS Server Configuration

Troubleshoot

Internet Security Association and Key Management Protocol (ISAKMP) Debugs

AAA debugs

Introduction

This document describes the behavior for Extended Authentication (XAUTH) for VPN users when both Authentication and Authorization are configured.

Prerequisites

Requirements

Cisco recommends that you have knowledge of these topics:

Authentication, Authorization, and Accounting (AAA)
Remote Access VPN

Components Used

The information in this document is based on a Cisco Aggregation Services Router (ASR)1000 Series that runs Cisco IOS^® XE software.

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.

Problem

VPN users are configured in order to be authenticated and authorized by a RADIUS server. The configuration on the ASR is shown here:

aaa group server radius ACS-Rad
 server-private 10.88.171.27 key cisco123
 ip vrf forwarding Mgmt-intf
aaa group server tacacs+ ACS-Tac
 server-private 10.88.171.27 key cisco123
 ip vrf forwarding Mgmt-intf
aaa authentication login VPN_Client group ACS-Rad
aaa authentication login login_local local
aaa authorization network VPN_Client group ACS-Rad 
aaa authorization network login_local local 
aaa accounting network VPN_Client start-stop group ACS-Rad
aaa accounting network login_local start-stop group ACS-Rad
aaa session-id common

However, whenever you try to authenticate, you never get prompted for your credentials. On the client, this error message is seen in the log messages:

Unable to establish Phase 1 SA with server "X.X.X.X" because of
"DEL_REASON_PEER_NOT_RESPONDING"

The debugs on the ASR indicate that the VPN group name is used as the User-Name for the authorization attempt.

Sep 26 20:01:49.298: RADIUS(000025EA): Sending a IPv4 Radius Packet
Sep 26 20:01:49.298: RADIUS(000025EA): Send Access-Request to X.X.X.X id
1645/88,len 123
Sep 26 20:01:49.298: RADIUS:  authenticator 0B 18 41 30 23 35 91 D5 - C3 DE 78
4E BB AC 30 4C
Sep 26 20:01:49.298: RADIUS:  User-Name           [1]   19  "vpnclient.cisco.com"
Sep 26 20:01:49.298: RADIUS:  User-Password       [2]   18  *
Sep 26 20:01:49.298: RADIUS:  Calling-Station-Id  [31]  16  "X.X.X.X"
Sep 26 20:01:49.298: RADIUS:  NAS-Port-Type       [61]  6   Virtual              [5]
Sep 26 20:01:49.298: RADIUS:  NAS-Port            [5]   6   0
Sep 26 20:01:49.299: RADIUS:  NAS-Port-Id         [87]  16  "X.X.X.X"
Sep 26 20:01:49.299: RADIUS:  Service-Type        [6]   6   Outbound             [5]
Sep 26 20:01:49.299: RADIUS:  NAS-IP-Address      [4]   6   192.168.0.55
Sep 26 20:01:49.299: RADIUS:  Acct-Session-Id     [44]  10  "00002CD6"
Sep 26 20:01:49.299: RADIUS(000025EA): Started 5 sec timeout
Sep 26 20:01:49.326: RADIUS: Received from id 1645/88 X.X.X.X:1812, Access-Accept,
len 26
Sep 26 20:01:49.326: RADIUS:  authenticator D3 9D 20 7E 09 89 68 BD - 1A DF A3
B6 6E 25 8D 77
Sep 26 20:01:49.326: RADIUS:  Service-Type        [6]   6   Framed                [2]
Sep 26 20:01:49.326: RADIUS(000025EA): Received from id 1645/88
Sep 26 
iacc02.crt#20:01:49.326: ISAKMP:(0):ISAKMP/tunnel: received callback from AAA
Sep 26 20:01:49.326: ISAKMP/tunnel: received tunnel atts
Sep 26 20:01:49.326: ISAKMP:Error - skey id.

Note: However, everything works fine when local authorization is configured.

Solution

The reported behavior is expected and not a bug. Remote Access VPN has two separate authentication processess:

Preshared key authentication for the tunnel to which the user connects.
XAUTH which authenticates the individual user.

XAUTH is Phase 1.5 and occurs only after the preshared key authentication succeeds in Phase 1. The reason you are not able to see a user prompt for a password is because Phase 1 has not yet completed. The username that is sent in the debugs is actually for the Phase 1 preshared key authentication.

Local Authorization Versus RADIUS Authorization

When local authoriation is configured, the VPN headend picks up the key value configured under the group configuration in order to complete Phase 1. This allows phase 1 to complete, so the router can proceed to XAUTH:

*Dec 26 12:42:13.926: ISAKMP:(0):ISAKMP/tunnel: setting up tunnel vpnclient
pw request
*Dec 26 12:42:13.926: AAA/AUTHOR (0x12): Pick method list 'login_local'
*Dec 26 12:42:13.926: ISAKMP:(0):ISAKMP/tunnel: Tunnel vpnclient PW Request
successfully sent to AAA
*Dec 26 12:42:13.926: ISAKMP:(0):Input = IKE_MESG_FROM_PEER, IKE_AM_EXCH
*Dec 26 12:42:13.926: ISAKMP:(0):Old State = IKE_READY  New State =
IKE_R_AM_AAA_AWAIT 

*Dec 26 12:42:13.927: ISAKMP:(0):ISAKMP/tunnel: received callback from AAA
AAA/AUTHOR/IKE: Processing AV tunnel-password
AAA/AUTHOR/IKE: Processing AV default-domain
AAA/AUTHOR/IKE: Processing AV addr-pool
AAA/AUTHOR/IKE: Processing AV dns-servers
AAA/AUTHOR/IKE: Processing AV wins-servers
AAA/AUTHOR/IKE: Processing AV route-metric
AAA/AUTHOR/IKE: Processing AV max-users
AAA/AUTHOR/IKE: Processing AV max-logins
AAA/AUTHOR/IKE: Processing AV netmask
*Dec 26 12:42:13.927: ISAKMP/tunnel: received tunnel atts
*Dec 26 12:42:13.927: ISAKMP:(35002): constructed NAT-T vendor-02 ID
*Dec 26 12:42:13.927: ISAKMP:(35002):SA is doing pre-shared key authentication
plus XAUTH using id type ID_IPV4_ADDR
*Dec 26 12:42:13.927: ISAKMP (35002): ID payload 
        next-payload : 10
        type         : 1 
        address      : 172.16.161.24 
        protocol     : 0 
        port         : 0 
        length       : 12
*Dec 26 12:42:13.927: ISAKMP:(35002):Total payload length: 12
*Dec 26 12:42:13.927: ISAKMP:(35002): sending packet to X.X.X.X my_port 500
peer_port 65328 (R) AG_INIT_EXCH
*Dec 26 12:42:13.927: ISAKMP:(35002):Sending an IKE IPv4 Packet.
*Dec 26 12:42:13.927: ISAKMP:(35002):Input = IKE_MESG_FROM_AAA, PRESHARED_KEY_REPLY
*Dec 26 12:42:13.927: ISAKMP:(35002):Old State = IKE_R_AM_AAA_AWAIT  New State =
IKE_R_AM2 

*Dec 26 12:42:14.017: ISAKMP (35002): received packet from X.X.X.X dport 4500 sport
59464 Mgmt-intf (R) AG_INIT_EXCH
*Dec 26 12:42:14.017: ISAKMP:(35002): processing HASH payload. message ID = 0
*Dec 26 12:42:14.017: ISAKMP:(35002): processing NOTIFY INITIAL_CONTACT protocol 1
        spi 0, message ID = 0, sa = 0x7F7796C1DDC0
*Dec 26 12:42:14.018: ISAKMP:received payload type 20
*Dec 26 12:42:14.018: ISAKMP (35002): His hash no match - this node outside NAT
*Dec 26 12:42:14.018: ISAKMP:received payload type 20
*Dec 26 12:42:14.018: ISAKMP (35002): His hash no match - this node outside NAT
*Dec 26 12:42:14.018: ISAKMP:(35002):SA authentication status:
        authenticated
*Dec 26 12:42:14.018: ISAKMP:(35002):SA has been authenticated with X.X.X.X
*Dec 26 12:42:14.018: ISAKMP:(35002):Detected port,floating to port = 59464
*Dec 26 12:42:14.018: ISAKMP: Trying to find existing peer
X.X.X.X/X.X.X.X/59464/Outside
*Dec 26 12:42:14.018: ISAKMP:(35002):SA authentication status:
        authenticated

*Dec 26 12:42:14.018: ISAKMP AAA: Profile vpnclient.cisco.com in use with AAA list
VPN_Client for peer X.X.X.X
*Dec 26 12:42:14.018: ISAKMP AAA: No peer record for address X.X.X.X, port 59464.
Create Accounting Record
*Dec 26 12:42:14.018: ISAKMP: Attempting to insert peer index node : 0x2
*Dec 26 12:42:14.018: ISAKMP AAA: Create Accounting Record 0x7F779645B5E0 for peer
X.X.X.X/59464 - peer-index 0x2
*Dec 26 12:42:14.018: ISAKMP AAA: NAS Port Id is already set to X.X.X.X
*Dec 26 12:42:14.018: ISAKMP AAA: crypto_ikmp_aaa_acct_rec_create: pki_sd 0

*Dec 26 12:42:14.018: ISAKMP:(35002):Input = IKE_MESG_FROM_PEER, IKE_AM_EXCH
*Dec 26 12:42:14.018: ISAKMP:(35002):Old State = IKE_R_AM2  New State =
IKE_P1_COMPLETE 

*Dec 26 12:42:14.018: ISAKMP:(35002):Need XAUTH
*Dec 26 12:42:14.018: ISAKMP: set new node 2793554424 to CONF_XAUTH   
*Dec 26 12:42:14.018: ISAKMP/xauth: request attribute XAUTH_USER_NAME_V2
*Dec 26 12:42:14.018: ISAKMP/xauth: request attribute XAUTH_USER_PASSWORD_V2
*Dec 26 12:42:14.018: ISAKMP:(35002): initiating peer config to X.X.X.X.
ID = 2793554424
*Dec 26 12:42:14.018: ISAKMP:(35002): sending packet to X.X.X.X my_port 4500
peer_port 59464 (R) CONF_XAUTH   
*Dec 26 12:42:14.018: ISAKMP:(35002):Sending an IKE IPv4 Packet.
*Dec 26 12:42:14.018: ISAKMP:(35002):Input = IKE_MESG_INTERNAL,
IKE_PHASE1_COMPLETE
*Dec 26 12:42:14.018: ISAKMP:(35002):Old State = IKE_P1_COMPLETE  New State =
IKE_XAUTH_REQ_SENT 

*Dec 26 12:42:21.572: ISAKMP (35002): received packet from X.X.X.X dport 4500
sport 59464 Mgmt-intf (R) CONF_XAUTH   
*Dec 26 12:42:21.572: ISAKMP:(35002):processing transaction payload from
X.X.X.X. message ID = 2793554424
*Dec 26 12:42:21.572: ISAKMP: Config payload REPLY
*Dec 26 12:42:21.572: ISAKMP/xauth: reply attribute XAUTH_USER_NAME_V2
*Dec 26 12:42:21.572: ISAKMP/xauth: reply attribute XAUTH_USER_PASSWORD_V2
*Dec 26 12:42:21.572: ISAKMP AAA: NAS Port Id is already set to X.X.X.X
*Dec 26 12:42:21.572: ISAKMP/Authen: unique id = 19
*Dec 26 12:42:21.572: ISAKMP:(35002):AAA Authen: setting up authen_request
*Dec 26 12:42:21.572: AAA/AUTHEN/LOGIN (00000013): Pick method list 'VPN_Client' 
*Dec 26 12:42:21.572: ISAKMP:(35002):AAA Authen: Successfully sent authen
info to AAA

*Dec 26 12:42:21.572: ISAKMP:(35002):deleting node 2793554424 error FALSE
reason "Done with xauth request/reply exchange"
*Dec 26 12:42:21.572: ISAKMP:(35002):Input = IKE_MESG_FROM_PEER, IKE_CFG_REPLY
*Dec 26 12:42:21.572: ISAKMP:(35002):Old State = IKE_XAUTH_REQ_SENT  New
State = IKE_XAUTH_AAA_CONT_LOGIN_AWAIT 

*Dec 26 12:42:21.573: RADIUS/ENCODE(00000013):Orig. component type = VPN IPSEC
*Dec 26 12:42:21.573: RADIUS:  AAA Unsupported Attr: interface         [221]
13  32631
*Dec 26 12:42:21.573: RADIUS/ENCODE(00000013): dropping service type,
"radius-server attribute 6 on-for-login-auth" is off
*Dec 26 12:42:21.573: RADIUS(00000013): Config NAS IP: 0.0.0.0
*Dec 26 12:42:21.573: RADIUS(00000013): Config NAS IPv6: ::
*Dec 26 12:42:21.573: Getting session id for EXEC(00000013) : db=7F7792DEEAB8
*Dec 26 12:42:21.573: RADIUS/ENCODE(00000013): acct_session_id: 8
*Dec 26 12:42:21.573: RADIUS(00000013): sending
*Dec 26 12:42:21.573: RADIUS/ENCODE: Best Local IP-Address X.X.X.X for
Radius-Server X.X.X.X
*Dec 26 12:42:21.573: RADIUS(00000013): Sending a IPv4 Radius Packet
*Dec 26 12:42:21.573: RADIUS(00000013): Send Access-Request to 10.88.171.27:1645
id 1645/1,len 95
*Dec 26 12:42:21.573: RADIUS:  authenticator B6 8C 79 D9 91 0C 79 50 - CB B0
2A 87 2A 61 03 E8
*Dec 26 12:42:21.573: RADIUS:  User-Name           [1]   10  "vpnclient-user"
*Dec 26 12:42:21.573: RADIUS:  User-Password       [2]   18  *
*Dec 26 12:42:21.573: RADIUS:  Calling-Station-Id  [31]  14  "X.X.X.X"
*Dec 26 12:42:21.573: RADIUS:  NAS-Port-Type       [61]  6   Virtual          [5]
*Dec 26 12:42:21.573: RADIUS:  NAS-Port            [5]   6   0                         
*Dec 26 12:42:21.573: RADIUS:  NAS-Port-Id         [87]  15  "X.X.X.X"
*Dec 26 12:42:21.573: RADIUS:  NAS-IP-Address      [4]   6   X.X.X.X             
*Dec 26 12:42:21.573: RADIUS(00000013): Started 5 sec timeout
*Dec 26 12:42:21.671: RADIUS: Received from id 1645/1 X.X.X.X:1645, Access-Accept,
len 56
*Dec 26 12:42:21.671: RADIUS:  authenticator E7 C1 B1 3D 04 59 48 22 - 4B 80 9D
1A 5E CA 0A A6
*Dec 26 12:42:21.671: RADIUS:  User-Name           [1]   10  "vpnclient-user"
*Dec 26 12:42:21.671: RADIUS:  Class               [25]  26  
*Dec 26 12:42:21.671: RADIUS:   43 41 43 53 3A 41 43 53 2D 35 78 2F 31 37 33 32 
[CACS:ACS-5x/1732]
*Dec 26 12:42:21.671: RADIUS:   37 32 35 30 33 2F 31 34          [ 72503/14]
*Dec 26 12:42:21.671: RADIUS(00000013): Received from id 1645/1
*Dec 26 12:42:21.672: ISAKMP:(35002):ISAKMP/author: Class attribute (len=24)
'CACS:ACS-5x/173272503/14'
*Dec 26 12:42:21.672: ISAKMP:(35002):AAA Authen: No group atts added
*Dec 26 12:42:21.672: ISAKMP: set new node 1771945814 to CONF_XAUTH   
*Dec 26 12:42:21.672: ISAKMP:(35002): initiating peer config to X.X.X.X. ID =
1771945814
*Dec 26 12:42:21.672: ISAKMP:(35002): sending packet to X.X.X.X my_port 4500
peer_port 59464 (R) CONF_XAUTH   
*Dec 26 12:42:21.672: ISAKMP:(35002):Sending an IKE IPv4 Packet.
*Dec 26 12:42:21.672: ISAKMP:(35002):Input = IKE_MESG_FROM_AAA,
IKE_AAA_CONT_LOGIN
*Dec 26 12:42:21.672: ISAKMP:(35002):Old State = IKE_XAUTH_AAA_CONT_LOGIN_AWAIT 
New State = IKE_XAUTH_SET_SENT 

*Dec 26 12:42:21.759: ISAKMP (35002): received packet from X.X.X.X dport 4500 sport
59464 Mgmt-intf (R) CONF_XAUTH   
*Dec 26 12:42:21.759: ISAKMP:(35002):processing transaction payload from X.X.X.X.
message ID = 1771945814
*Dec 26 12:42:21.759: ISAKMP: Config payload ACK
*Dec 26 12:42:21.759: ISAKMP:(35002):       (blank) XAUTH ACK Processed
*Dec 26 12:42:21.759: ISAKMP:(35002):deleting node 1771945814 error FALSE reason
"Transaction mode done"
*Dec 26 12:42:21.759: ISAKMP:(35002):Talking to a Unity Client
*Dec 26 12:42:21.759: ISAKMP:(35002):Input = IKE_MESG_FROM_PEER, IKE_CFG_ACK
*Dec 26 12:42:21.759: ISAKMP:(35002):Old State = IKE_XAUTH_SET_SENT  New State =
IKE_P1_COMPLETE 

*Dec 26 12:42:21.759: ISAKMP:(35002):Input = IKE_MESG_INTERNAL, IKE_PHASE1_COMPLETE
*Dec 26 12:42:21.759: ISAKMP:(35002):Old State = IKE_P1_COMPLETE  New State =
IKE_P1_COMPLETE 

*Dec 26 12:42:21.763: ISAKMP (35002): received packet from X.X.X.X dport 4500 sport
59464 Mgmt-intf (R) QM_IDLE      
*Dec 26 12:42:21.763: ISAKMP: set new node 3504137478 to QM_IDLE      
*Dec 26 12:42:21.763: ISAKMP:(35002):processing transaction payload from X.X.X.X.
message ID = 3504137478
*Dec 26 12:42:21.763: ISAKMP: Config payload REQUEST
*Dec 26 12:42:21.763: ISAKMP:(35002):checking request:
*Dec 26 12:42:21.763: ISAKMP:    IP4_ADDRESS
*Dec 26 12:42:21.763: ISAKMP:    IP4_NETMASK
*Dec 26 12:42:21.763: ISAKMP:    IP4_DNS
*Dec 26 12:42:21.763: ISAKMP:    IP4_NBNS
*Dec 26 12:42:21.763: ISAKMP:    ADDRESS_EXPIRY
*Dec 26 12:42:21.763: ISAKMP:    MODECFG_BANNER
*Dec 26 12:42:21.763: ISAKMP:    MODECFG_SAVEPWD
*Dec 26 12:42:21.763: ISAKMP:    DEFAULT_DOMAIN
*Dec 26 12:42:21.763: ISAKMP:    SPLIT_INCLUDE
*Dec 26 12:42:21.763: ISAKMP:    SPLIT_DNS
*Dec 26 12:42:21.763: ISAKMP:    PFS
*Dec 26 12:42:21.763: ISAKMP:    MODECFG_BROWSER_PROXY
*Dec 26 12:42:21.763: ISAKMP:    BACKUP_SERVER
*Dec 26 12:42:21.763: ISAKMP:    MODECFG_SMARTCARD_REMOVAL_DISCONNECT
*Dec 26 12:42:21.763: ISAKMP:    APPLICATION_VERSION
*Dec 26 12:42:21.763: ISAKMP: Client Version is : Cisco Systems VPN Client
5.0.07.0440:WinNTp
*Dec 26 12:42:21.763: ISAKMP:    FW_RECORD
*Dec 26 12:42:21.763: ISAKMP:    MODECFG_HOSTNAME
*Dec 26 12:42:21.763: ISAKMP:(35002):ISAKMP/author: setting up the authorization
request for vpnclient
*Dec 26 12:42:21.763: AAA/AUTHOR (0x13): Pick method list 'login_local'
*Dec 26 12:42:21.763: ISAKMP/author: Author request for group vpnclientsuccessfully
sent to AAA
*Dec 26 12:42:21.763: ISAKMP:(35002):Input = IKE_MESG_FROM_PEER, IKE_CFG_REQUEST
*Dec 26 12:42:21.763: ISAKMP:(35002):Old State = IKE_P1_COMPLETE  New State =
IKE_CONFIG_AUTHOR_AAA_AWAIT 

*Dec 26 12:42:21.764: ISAKMP:(0):ISAKMP/author: received callback from AAA
AAA/AUTHOR/IKE: Processing AV tunnel-password
AAA/AUTHOR/IKE: Processing AV default-domain
AAA/AUTHOR/IKE: Processing AV addr-pool
AAA/AUTHOR/IKE: Processing AV dns-servers
AAA/AUTHOR/IKE: Processing AV wins-servers
*Dec 26 12:42:21.764: 
AAA/AUTHOR/IKE: no WINS addresses
AAA/AUTHOR/IKE: Processing AV route-metric
AAA/AUTHOR/IKE: Processing AV max-users
AAA/AUTHOR/IKE: Processing AV max-logins
AAA/AUTHOR/IKE: Processing AV netmask
*Dec 26 12:42:21.764: ISAKMP:(35002):ISAKMP/author: No Class attributes
*Dec 26 12:42:21.764: ISAKMP:(35002):attributes sent in message:
*Dec 26 12:42:21.764:         Address: 0.2.0.0
*Dec 26 12:42:21.766: ISAKMP:(35002):allocating address X.X.X.X
*Dec 26 12:42:21.766: ISAKMP: Sending private address: X.X.X.X
*Dec 26 12:42:21.766: ISAKMP: Sending subnet mask: 255.255.255.0
*Dec 26 12:42:21.766: ISAKMP: Sending IP4_DNS server address: X.X.X.X
*Dec 26 12:42:21.766: ISAKMP: Sending ADDRESS_EXPIRY seconds left to use the
address: 86392
*Dec 26 12:42:21.766: ISAKMP: Sending save password reply value 0
*Dec 26 12:42:21.766: ISAKMP: Sending DEFAULT_DOMAIN default domain name:
vpnclient.cisco.com
*Dec 26 12:42:21.766: ISAKMP: Sending smartcard_removal_disconnect reply
                  value 0
*Dec 26 12:42:21.766: ISAKMP: Sending APPLICATION_VERSION string: Cisco IOS Software,
IOS-XE Software (X86_64_LINUX_IOSD-ADVENTERPRISEK9-M), Version 15.2(4)S,
RELEASE SOFTWARE (fc4)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2012 by Cisco Systems, Inc.
Compiled Mon 23-Jul-12 20:02 by mcpre
*Dec 26 12:42:21.766: ISAKMP (35002): Unknown Attr: MODECFG_HOSTNAME (0x700A)
*Dec 26 12:42:21.766: ISAKMP:(35002): responding to peer config from 72.163.84.76.
ID = 3504137478
*Dec 26 12:42:21.766: ISAKMP: Marking node 3504137478 for late deletion
*Dec 26 12:42:21.766: ISAKMP:(35002): sending packet to X.X.X.X my_port 4500 peer_port
59464 (R) CONF_ADDR    
*Dec 26 12:42:21.766: ISAKMP:(35002):Sending an IKE IPv4 Packet.
*Dec 26 12:42:21.766: ISAKMP:(35002):Talking to a Unity Client
*Dec 26 12:42:21.766: ISAKMP:(35002):Input = IKE_MESG_FROM_AAA, IKE_AAA_GROUP_ATTR
*Dec 26 12:42:21.766: ISAKMP:(35002):Old State = IKE_CONFIG_AUTHOR_AAA_AWAIT  New
State = IKE_P1_COMPLETE 

*Dec 26 12:42:21.766: ISAKMP:FSM error - Message from AAA grp/user.

*Dec 26 12:42:21.766: ISAKMP:(35002):Input = IKE_MESG_INTERNAL, IKE_PHASE1_COMPLETE
*Dec 26 12:42:21.766: ISAKMP:(35002):Old State = IKE_P1_COMPLETE  New State =
IKE_P1_COMPLETE

When the router is configured to authorize against the RADIUS server, it does not work because in order to get the key (for preshared authentication), it must do a access-request query to the RADIUS server. However, the access-request query requires a username to be sent to RADIUSA and since XAUTH is not done yet, it cannot use the client user name. In this situation, it uses the group name as the user name instead. However, since the RADIUS server has not been set up to verify any user by that ID, it rejects the request. Because of this, Phase 1 never completes, and the user is never prompted for credentials.

Working Configuration

Router Configuration

Here is the configuration for the router.

aaa group server radius Radius-Server
 server-private X.X.X.X auth-port 1812 acct-port 1813 key 7 <removed>


aaa authentication login VPN_Client group Radius-Server
aaa authorization network VPN_Client Radius-Server
aaa accounting network VPN_Client start-stop group Radius-Server


crypto isakmp policy 10
 encr 3des
 authentication pre-share
 group 2


crypto isakmp client configuration group vpnclient
 key <removed>
 dns x.x.x.x
 wins x.x.x.x
 domain cisco.com
 pool VPN_Pool
 acl 101
 group-lock


crypto isakmp profile vpnclient.cisco.com
 match identity group vpnclinet
 client authentication list VPN_Client
 isakmp authorization list VPN_Client
 client configuration address respond
 accounting VPN_Client


crypto ipsec transform-set TRANS-DES esp-des esp-md5-hmac 
 mode tunnel


crypto dynamic-map DYN-MAP 10
 set transform-set TRANS-DES
 set isakmp-profile vpnclient.cisco.com
 reverse-route


crypto map VPN local-address TenGigabitEthernet 0/0/0
crypto map VPN 10 ipsec-isakmp dynamic DYN-MAP


interface TenGigabitEthernet0/0/0
 ip address X.X.X.X 255.255.255.0
 crypto map VPN

RADIUS Server Configuration

Complete these steps in order to configure the RADIUS server.

Configure the Groupname user:
Configure an Authorization profile in order to give all Attribute Value (AV) Pairs:
Configure an Access policy in order to permit the connection and use that profile:

Troubleshoot

The Output Interpreter Tool (registered customers only) supports certain show commands. Use the Output Interpreter Tool in order to view an analysis of show command output.

Note: Refer to Important Information on Debug Commands before you use debug commands.

These debugs are enabled on the VPN headend:

Internet Security Association and Key Management Protocol (ISAKMP) Debugs

debug crypto isakmp

AAA debugs

debug aaa authentication
debug aaa authorization
debug aaa accounting
debug radius authentication

Revision History

Revision	Publish Date	Comments
1.0	11-Apr-2014	Initial Release

Contributed by Cisco Engineers

Osvaldo Garcia and Atri Basu
Cisco TAC Engineers.

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Remote Access VPN Does Not Work When RADIUS Authentication and Authorization is Configured

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Contents

Introduction

Prerequisites

Requirements

Components Used

Problem

Solution

Local Authorization Versus RADIUS Authorization

Working Configuration

Router Configuration

RADIUS Server Configuration

Troubleshoot

Internet Security Association and Key Management Protocol (ISAKMP) Debugs

AAA debugs

Revision History

Contributed by Cisco Engineers

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