RADIUS Servers for AAA

This chapter describes how to configure RADIUS servers for AAA.

About RADIUS Servers for AAA

The ASA supports the following RFC-compliant RADIUS servers for AAA:

  • Cisco Secure ACS 3.2, 4.0, 4.1, 4.2, and 5.x

  • Cisco Identity Services Engine (ISE)

  • RSA RADIUS in RSA Authentication Manager 5.2, 6.1, and 7.x

  • Microsoft

Supported Authentication Methods

The ASA supports the following authentication methods with RADIUS servers:

  • PAP—For all connection types.

  • CHAP and MS-CHAPv1—For L2TP-over-IPsec connections.

  • MS-CHAPv2—For L2TP-over-IPsec connections, and for regular IPsec remote access connections when the password management feature is enabled. You can also use MS-CHAPv2 with clientless connections.

  • Authentication Proxy modes—For RADIUS-to Active-Directory, RADIUS-to-RSA/SDI, RADIUS- to-Token server, and RSA/SDI-to-RADIUS connections,


    Note

    To enable MS-CHAPv2 as the protocol used between the ASA and the RADIUS server for a VPN connection, password management must be enabled in the tunnel group general attributes. Enabling password management generates an MS-CHAPv2 authentication request from the ASA to the RADIUS server. See the description of the password-management command for details.

    If you use double authentication and enable password management in the tunnel group, then the primary and secondary authentication requests include MS-CHAPv2 request attributes. If a RADIUS server does not support MS-CHAPv2, then you can configure that server to send a non-MS-CHAPv2 authentication request by using the no mschapv2-capable command.

User Authorization of VPN Connections

The ASA can use RADIUS servers for user authorization of VPN remote access and firewall cut-through-proxy sessions using dynamic ACLs or ACL names per user. To implement dynamic ACLs, you must configure the RADIUS server to support them. When the user authenticates, the RADIUS server sends a downloadable ACL or ACL name to the ASA. Access to a given service is either permitted or denied by the ACL. The ASA deletes the ACL when the authentication session expires.

In addition to ACLs, the ASA supports many other attributes for authorization and setting of permissions for VPN remote access and firewall cut-through proxy sessions.

Supported Sets of RADIUS Attributes

The ASA supports the following sets of RADIUS attributes:

  • Authentication attributes defined in RFC 2138 and 2865.

  • Accounting attributes defined in RFC 2139 and 2866.

  • RADIUS attributes for tunneled protocol support, defined in RFC 2868 and 6929.

  • Cisco IOS Vendor-Specific Attributes (VSAs), identified by RADIUS vendor ID 9.

  • Cisco VPN-related VSAs, identified by RADIUS vendor ID 3076.

  • Microsoft VSAs, defined in RFC 2548.

Supported RADIUS Authorization Attributes

Authorization refers to the process of enforcing permissions or attributes. A RADIUS server defined as an authentication server enforces permissions or attributes if they are configured. These attributes have vendor ID 3076.

The following table lists the supported RADIUS attributes that can be used for user authorization.


Note

RADIUS attribute names do not contain the cVPN3000 prefix. Cisco Secure ACS 4.x supports this new nomenclature, but attribute names in pre-4.0 ACS releases still include the cVPN3000 prefix. The ASAs enforce the RADIUS attributes based on attribute numeric ID, not attribute name.

All attributes listed in the following table are downstream attributes that are sent from the RADIUS server to the ASA except for the following attribute numbers: 146, 150, 151, and 152. These attribute numbers are upstream attributes that are sent from the ASA to the RADIUS server. RADIUS attributes 146 and 150 are sent from the ASA to the RADIUS server for authentication and authorization requests. All four previously listed attributes are sent from the ASA to the RADIUS server for accounting start, interim-update, and stop requests. Upstream RADIUS attributes 146, 150, 151, and 152 were introduced in Version 8.4(3).

Table 1. Supported RADIUS Authorization Attributes

Attribute Name

ASA

Attr. No.

Syntax/Type

Single or Multi-
Valued

Description or Value

Access-Hours

Y

1

String

Single

Name of the time range, for example, Business-hours

Access-List-Inbound

Y

86

String

Single

ACL ID

Access-List-Outbound

Y

87

String

Single

ACL ID

Address-Pools

Y

217

String

Single

Name of IP local pool

Allow-Network-Extension-Mode

Y

64

Boolean

Single

0 = Disabled
1 = Enabled

Authenticated-User-Idle-Timeout

Y

50

Integer

Single

1-35791394 minutes

Authorization-DN-Field

Y

67

String

Single

Possible values: UID, OU, O, CN, L, SP, C, EA, T, N, GN, SN, I, GENQ, DNQ, SER, use-entire-name

Authorization-Required

66

Integer

Single

0 = No
1 = Yes

Authorization-Type

Y

65

Integer

Single

0 = None
1 = RADIUS
2 = LDAP

Banner1

Y

15

String

Single

Banner string to display for Cisco VPN remote access sessions: IPsec IKEv1, Secure Client SSL-TLS/DTLS/IKEv2, and Clientless SSL

Banner2

Y

36

String

Single

Banner string to display for Cisco VPN remote access sessions: IPsec IKEv1, Secure Client SSL-TLS/DTLS/IKEv2, and Clientless SSL. The Banner2 string is concatenated to the Banner1 string , if configured.

Cisco-IP-Phone-Bypass

Y

51

Integer

Single

0 = Disabled
1 = Enabled

Cisco-LEAP-Bypass

Y

75

Integer

Single

0 = Disabled
1 = Enabled

Client Type

Y

150

Integer

Single

1 = Cisco VPN Client (IKEv1)
2 = Secure Client SSL VPN
3 = Clientless SSL VPN
4 = Cut-Through-Proxy
5 = L2TP/IPsec SSL VPN
6 = Secure Client IPsec VPN (IKEv2)

Client-Type-Version-Limiting

Y

77

String

Single

IPsec VPN version number string

DHCP-Network-Scope

Y

61

String

Single

IP Address

Extended-Authentication-On-Rekey

Y

122

Integer

Single

0 = Disabled
1 = Enabled

Framed-Interface-Id

Y

96

String

Single

Assigned IPv6 interface ID. Combines with Framed-IPv6-Prefix to create a complete assigned IPv6 address. For example: Framed-Interface-ID=1:1:1:1 combined with Framed-IPv6-Prefix=2001:0db8::/64 gives the assigned IP address 2001:0db8::1:1:1:1.

Framed-IPv6-Prefix

Y

97

String

Single

Assigned IPv6 prefix and length. Combines with Framed-Interface-Id to create a complete assigned IPv6 address. For example: prefix 2001:0db8::/64 combined with Framed-Interface-Id=1:1:1:1 gives the IP address 2001:0db8::1:1:1:1. You can use this attribute to assign an IP address without using Framed-Interface-Id, by assigning the full IPv6 address with prefix length /128, for example, Framed-IPv6-Prefix=2001:0db8::1/128.

Group-Policy

Y

25

String

Single

Sets the group policy for the remote access VPN session. For Versions 8.2.x and later, use this attribute instead of IETF-Radius-Class. You can use one of the following formats:

  • group policy name

  • OU=group policy name

  • OU=group policy name;

IE-Proxy-Bypass-Local

83

Integer

Single

0 = None
1 = Local

IE-Proxy-Exception-List

82

String

Single

New line (\n) separated list of DNS domains

IE-Proxy-PAC-URL

Y

133

String

Single

PAC address string

IE-Proxy-Server

80

String

Single

IP address

IE-Proxy-Server-Policy

81

Integer

Single

1 = No Modify
2 = No Proxy
3 = Auto detect
4 = Use Concentrator Setting

IKE-KeepAlive-Confidence-Interval

Y

68

Integer

Single

10-300 seconds

IKE-Keepalive-Retry-Interval

Y

84

Integer

Single

2-10 seconds

IKE-Keep-Alives

Y

41

Boolean

Single

0 = Disabled
1 = Enabled

Intercept-DHCP-Configure-Msg

Y

62

Boolean

Single

0 = Disabled
1 = Enabled

IPsec-Allow-Passwd-Store

Y

16

Boolean

Single

0 = Disabled
1 = Enabled

IPsec-Authentication

13

Integer

Single

0 = None
1 = RADIUS
2 = LDAP (authorization only)
3 = NT Domain
4 = SDI
5 = Internal
6 = RADIUS with Expiry
7 = Active Directory

IPsec-Auth-On-Rekey

Y

42

Boolean

Single

0 = Disabled
1 = Enabled

IPsec-Backup-Server-List

Y

60

String

Single

Server Addresses (space delimited)

IPsec-Backup-Servers

Y

59

String

Single

1 = Use Client-Configured list
2 = Disable and clear client list
3 = Use Backup Server list

IPsec-Client-Firewall-Filter-Name

57

String

Single

Specifies the name of the filter to be pushed to the client as firewall policy

IPsec-Client-Firewall-Filter-Optional

Y

58

Integer

Single

0 = Required
1 = Optional

IPsec-Default-Domain

Y

28

String

Single

Specifies the single default domain name to send to the client (1-255 characters).

IPsec-IKE-Peer-ID-Check

Y

40

Integer

Single

1 = Required
2 = If supported by peer certificate
3 = Do not check

IPsec-IP-Compression

Y

39

Integer

Single

0 = Disabled
1 = Enabled

IPsec-Mode-Config

Y

31

Boolean

Single

0 = Disabled
1 = Enabled

IPsec-Over-UDP

Y

34

Boolean

Single

0 = Disabled
1 = Enabled

IPsec-Over-UDP-Port

Y

35

Integer

Single

4001- 49151. The default is 10000.

IPsec-Required-Client-Firewall-Capability

Y

56

Integer

Single

0 = None
1 = Policy defined by remote FW Are-You-There (AYT)
2 = Policy pushed CPP
4 = Policy from server

IPsec-Sec-Association

12

String

Single

Name of the security association

IPsec-Split-DNS-Names

Y

29

String

Single

Specifies the list of secondary domain names to send to the client (1-255 characters).

IPsec-Split-Tunneling-Policy

Y

55

Integer

Single

0 = No split tunneling
1 = Split tunneling
2 = Local LAN permitted

IPsec-Split-Tunnel-List

Y

27

String

Single

Specifies the name of the network or ACL that describes the split tunnel inclusion list.

IPsec-Tunnel-Type

Y

30

Integer

Single

1 = LAN-to-LAN
2 = Remote access

IPsec-User-Group-Lock

33

Boolean

Single

0 = Disabled
1 = Enabled

IPv6-Address-Pools

Y

218

String

Single

Name of IP local pool-IPv6

IPv6-VPN-Filter

Y

219

String

Single

ACL value

L2TP-Encryption

21

Integer

Single

Bitmap:
1 = Encryption required
2 = 40 bits
4 = 128 bits
8 = Stateless-Req
15= 40/128-Encr/Stateless-Req

L2TP-MPPC-Compression

38

Integer

Single

0 = Disabled
1 = Enabled

Member-Of

Y

145

String

Single

Comma-delimited string, for example: 


Engineering, Sales

An administrative attribute that can be used in dynamic access policies. It does not set a group policy.

MS-Client-Subnet-Mask

Y

63

Boolean

Single

An IP address

NAC-Default-ACL

92

String

ACL

NAC-Enable

89

Integer

Single

0 = No
1 = Yes

NAC-Revalidation-Timer

91

Integer

Single

300-86400 seconds

NAC-Settings

Y

141

String

Single

Name of the NAC policy

NAC-Status-Query-Timer

90

Integer

Single

30-1800 seconds

Perfect-Forward-Secrecy-Enable

Y

88

Boolean

Single

0 = No
1 = Yes

PPTP-Encryption

20

Integer

Single

Bitmap:
1 = Encryption required
2 = 40 bits
4 = 128 bits
8 = Stateless-Required
15= 40/128-Encr/Stateless-Req

PPTP-MPPC-Compression

37

Integer

Single

0 = Disabled
1 = Enabled

Primary-DNS

Y

5

String

Single

An IP address

Primary-WINS

Y

7

String

Single

An IP address

Privilege-Level

Y

220

Integer

Single

An integer between 0 and 15.

Required-Client- Firewall-Vendor-Code

Y

45

Integer

Single

1 = Cisco Systems (with Cisco Integrated Client)
2 = Zone Labs
3 = NetworkICE
4 = Sygate
5 = Cisco Systems (with Cisco Intrusion Prevention Security Agent)

Required-Client-Firewall-Description

Y

47

String

Single

String

Required-Client-Firewall-Product-Code

Y

46

Integer

Single

Cisco Systems Products:

1 = Cisco Intrusion Prevention Security Agent or Cisco Integrated Client (CIC)

Zone Labs Products:
1 = Zone Alarm
2 = Zone AlarmPro
3 = Zone Labs Integrity

NetworkICE Product:
1 = BlackIce Defender/Agent

Sygate Products:
1 = Personal Firewall
2 = Personal Firewall Pro
3 = Security Agent

Required-Individual-User-Auth

Y

49

Integer

Single

0 = Disabled
1 = Enabled

Require-HW-Client-Auth

Y

48

Boolean

Single

0 = Disabled
1 = Enabled

Secondary-DNS

Y

6

String

Single

An IP address

Secondary-WINS

Y

8

String

Single

An IP address

SEP-Card-Assignment

9

Integer

Single

Not used

Session Subtype

Y

152

Integer

Single

0 = None
1 = Clientless
2 = Client
3 = Client Only

Session Subtype applies only when the Session Type (151) attribute has the following values: 1, 2, 3, and 4.

Session Type

Y

151

Integer

Single

0 = None
1 = Secure Client SSL VPN
2 = Secure Client IPSec VPN (IKEv2)
3 = Clientless SSL VPN
4 = Clientless Email Proxy
5 = Cisco VPN Client (IKEv1)
6 = IKEv1 LAN-LAN
7 = IKEv2 LAN-LAN
8 = VPN Load Balancing

Simultaneous-Logins

Y

2

Integer

Single

0-2147483647

Smart-Tunnel

Y

136

String

Single

Name of a Smart Tunnel

Smart-Tunnel-Auto

Y

138

Integer

Single

0 = Disabled
1 = Enabled
2 = AutoStart

Smart-Tunnel-Auto-Signon-Enable

Y

139

String

Single

Name of a Smart Tunnel Auto Signon list appended by the domain name

Strip-Realm

Y

135

Boolean

Single

0 = Disabled
1 = Enabled

SVC-Ask

Y

131

String

Single

0 = Disabled
1 = Enabled
3 = Enable default service
5 = Enable default clientless
(2 and 4 not used)

SVC-Ask-Timeout

Y

132

Integer

Single

5-120 seconds

SVC-DPD-Interval-Client

Y

108

Integer

Single

0 = Off
5-3600 seconds

SVC-DPD-Interval-Gateway

Y

109

Integer

Single

0 = Off)
5-3600 seconds

SVC-DTLS

Y

123

Integer

Single

0 = False
1 = True

SVC-Keepalive

Y

107

Integer

Single

0 = Off 
15-600 seconds

SVC-Modules

Y

127

String

Single

String (name of a module)

SVC-MTU

Y

125

Integer

Single

MTU value
256-1406 in bytes

SVC-Profiles

Y

128

String

Single

String (name of a profile)

SVC-Rekey-Time

Y

110

Integer

Single

0 = Disabled
1-10080 minutes

Tunnel Group Name

Y

146

String

Single

1-253 characters

Tunnel-Group-Lock

Y

85

String

Single

Name of the tunnel group or “none”

Tunneling-Protocols

Y

11

Integer

Single

1 = PPTP
2 = L2TP
4 = IPSec (IKEv1)
8 = L2TP/IPSec
16 = WebVPN
32 = SVC
64 = IPsec (IKEv2)
8 and 4 are mutually exclusive.
0 - 11, 16 - 27, 32 - 43, 48 - 59 are legal values.

Use-Client-Address

17

Boolean

Single

0 = Disabled
1 = Enabled

VLAN

Y

140

Integer

Single

0-4094

WebVPN-Access-List

Y

73

String

Single

Access-List name

WebVPN ACL

Y

73

String

Single

Name of a WebVPN ACL on the device

WebVPN-ActiveX-Relay

Y

137

Integer

Single

0 = Disabled
Otherwise = Enabled

WebVPN-Apply-ACL

Y

102

Integer

Single

0 = Disabled
1 = Enabled

WebVPN-Auto-HTTP-Signon

Y

124

String

Single

Reserved

WebVPN-Citrix-Metaframe-Enable

Y

101

Integer

Single

0 = Disabled
1 = Enabled

WebVPN-Content-Filter-Parameters

Y

69

Integer

Single

1 = Java ActiveX
2 = Java Script
4 = Image
8 = Cookies in images

WebVPN-Customization

Y

113

String

Single

Name of the customization

WebVPN-Default-Homepage

Y

76

String

Single

A URL such as http://example-example.com

WebVPN-Deny-Message

Y

116

String

Single

Valid string (up to 500 characters)

WebVPN-Download_Max-Size

Y

157

Integer

Single

0x7fffffff

WebVPN-File-Access-Enable

Y

94

Integer

Single

0 = Disabled
1 = Enabled

WebVPN-File-Server-Browsing-Enable

Y

96

Integer

Single

0 = Disabled
1 = Enabled

WebVPN-File-Server-Entry-Enable

Y

95

Integer

Single

0 = Disabled
1 = Enabled

WebVPN-Group-based-HTTP/HTTPS-Proxy-Exception-List

Y

78

String

Single

Comma-separated DNS/IP with an optional wildcard (*) (for example *.cisco.com, 192.168.1.*, wwwin.cisco.com)

WebVPN-Hidden-Shares

Y

126

Integer

Single

0 = None
1 = Visible

WebVPN-Home-Page-Use-Smart-Tunnel

Y

228

Boolean

Single

Enabled if clientless home page is to be rendered through Smart Tunnel.

WebVPN-HTML-Filter

Y

69

Bitmap

Single

1 = Java ActiveX
2 = Scripts
4 = Image
8 = Cookies

WebVPN-HTTP-Compression

Y

120

Integer

Single

0 = Off
1 = Deflate Compression

WebVPN-HTTP-Proxy-IP-Address

Y

74

String

Single

Comma-separated DNS/IP:port, with http= or https= prefix (for example http=10.10.10.10:80, https=11.11.11.11:443)

WebVPN-Idle-Timeout-Alert-Interval

Y

148

Integer

Single

0-30. 0 = Disabled.

WebVPN-Keepalive-Ignore

Y

121

Integer

Single

0-900

WebVPN-Macro-Substitution

Y

223

String

Single

Unbounded.

WebVPN-Macro-Substitution

Y

224

String

Single

Unbounded.

WebVPN-Port-Forwarding-Enable

Y

97

Integer

Single

0 = Disabled
1 = Enabled

WebVPN-Port-Forwarding-Exchange-Proxy-Enable

Y

98

Integer

Single

0 = Disabled
1 = Enabled

WebVPN-Port-Forwarding-HTTP-Proxy

Y

99

Integer

Single

0 = Disabled
1 = Enabled

WebVPN-Port-Forwarding-List

Y

72

String

Single

Port forwarding list name

WebVPN-Port-Forwarding-Name

Y

79

String

Single

String name (example, “Corporate-Apps”).

This text replaces the default string, “Application Access,” on the clientless portal home page.

WebVPN-Post-Max-Size

Y

159

Integer

Single

0x7fffffff

WebVPN-Session-Timeout-Alert-Interval

Y

149

Integer

Single

0-30. 0 = Disabled.

WebVPN Smart-Card-Removal-Disconnect

Y

225

Boolean

Single

0 = Disabled
1 = Enabled

WebVPN-Smart-Tunnel

Y

136

String

Single

Name of a Smart Tunnel

WebVPN-Smart-Tunnel-Auto-Sign-On

Y

139

String

Single

Name of a Smart Tunnel auto sign-on list appended by the domain name

WebVPN-Smart-Tunnel-Auto-Start

Y

138

Integer

Single

0 = Disabled
1 = Enabled
2 = Auto Start

WebVPN-Smart-Tunnel-Tunnel-Policy

Y

227

String

Single

One of “e networkname,” “i networkname,” or “a,” where networkname is the name of a Smart Tunnel network list, e indicates the tunnel excluded, i indicates the tunnel specified, and a indicates all tunnels.

WebVPN-SSL-VPN-Client-Enable

Y

103

Integer

Single

0 = Disabled
1 = Enabled

WebVPN-SSL-VPN-Client-Keep- Installation

Y

105

Integer

Single

0 = Disabled
1 = Enabled

WebVPN-SSL-VPN-Client-Required

Y

104

Integer

Single

0 = Disabled
1 = Enabled

WebVPN-SSO-Server-Name

Y

114

String

Single

Valid string

WebVPN-Storage-Key

Y

162

String

Single

WebVPN-Storage-Objects

Y

161

String

Single

WebVPN-SVC-Keepalive-Frequency

Y

107

Integer

Single

15-600 seconds, 0=Off

WebVPN-SVC-Client-DPD-Frequency

Y

108

Integer

Single

5-3600 seconds, 0=Off

WebVPN-SVC-DTLS-Enable

Y

123

Integer

Single

0 = Disabled
1 = Enabled

WebVPN-SVC-DTLS-MTU

Y

125

Integer

Single

MTU value is from 256-1406 bytes.

WebVPN-SVC-Gateway-DPD-Frequency

Y

109

Integer

Single

5-3600 seconds, 0=Off

WebVPN-SVC-Rekey-Time

Y

110

Integer

Single

4-10080 minutes, 0=Off

WebVPN-SVC-Rekey-Method

Y

111

Integer

Single

0 (Off), 1 (SSL), 2 (New Tunnel)

WebVPN-SVC-Compression

Y

112

Integer

Single

0 (Off), 1 (Deflate Compression)

WebVPN-UNIX-Group-ID (GID)

Y

222

Integer

Single

Valid UNIX group IDs

WebVPN-UNIX-User-ID (UIDs)

Y

221

Integer

Single

Valid UNIX user IDs

WebVPN-Upload-Max-Size

Y

158

Integer

Single

0x7fffffff

WebVPN-URL-Entry-Enable

Y

93

Integer

Single

0 = Disabled
1 = Enabled

WebVPN-URL-List

Y

71

String

Single

URL list name

WebVPN-User-Storage

Y

160

String

Single

WebVPN-VDI

Y

163

String

Single

List of settings

Supported IETF RADIUS Authorization Attributes

The following table lists the supported IETF RADIUS attributes.

Table 2. Supported IETF RADIUS Attributes

Attribute Name

ASA

Attr. No.

Syntax/Type

Single or Multi-
Valued

Description or Value

IETF-Radius-Class

Y

25

Single

For Versions 8.2.x and later, we recommend that you use the Group-Policy attribute (VSA 3076, #25):

  • group policy name

  • OU=group policy name

  • OU=group policy name

IETF-Radius-Filter-Id

Y

11

String

Single

ACL name that is defined on the ASA, which applies only to full tunnel IPsec and SSL VPN clients.

IETF-Radius-Framed-IP-Address

Y

n/a

String

Single

An IP address

IETF-Radius-Framed-IP-Netmask

Y

n/a

String

Single

An IP address mask

IETF-Radius-Idle-Timeout

Y

28

Integer

Single

Seconds

IETF-Radius-Service-Type

Y

6

Integer

Single

Seconds. Possible Service Type values:

  • .Administrative—User is allowed access to the configure prompt.

  • .NAS-Prompt—User is allowed access to the exec prompt.

  • .remote-access—User is allowed network access

IETF-Radius-Session-Timeout

Y

27

Integer

Single

Seconds

RADIUS Accounting Disconnect Reason Codes

These codes are returned if the ASA encounters a disconnect when sending packets:

Disconnect Reason Code

ACCT_DISC_USER_REQ = 1

ACCT_DISC_LOST_CARRIER = 2

ACCT_DISC_LOST_SERVICE = 3

ACCT_DISC_IDLE_TIMEOUT = 4

ACCT_DISC_SESS_TIMEOUT = 5

ACCT_DISC_ADMIN_RESET = 6

ACCT_DISC_ADMIN_REBOOT = 7

ACCT_DISC_PORT_ERROR = 8

ACCT_DISC_NAS_ERROR = 9

ACCT_DISC_NAS_REQUEST = 10

ACCT_DISC_NAS_REBOOT = 11

ACCT_DISC_PORT_UNNEEDED = 12

ACCT_DISC_PORT_PREEMPTED = 13

ACCT_DISC_PORT_SUSPENDED = 14

ACCT_DISC_SERV_UNAVAIL = 15

ACCT_DISC_CALLBACK = 16

ACCT_DISC_USER_ERROR = 17

ACCT_DISC_HOST_REQUEST = 18

ACCT_DISC_ADMIN_SHUTDOWN = 19

ACCT_DISC_SA_EXPIRED = 21

ACCT_DISC_MAX_REASONS = 22

Guidelines for RADIUS Servers for AAA

This section describes the guidelines and limitations that you should check before configuring RADIUS servers for AAA.

  • You can have up to 200 server groups in single mode or 4 server groups per context in multiple mode.

  • Each group can have up to 16 servers in single mode or 8 servers in multiple mode.

  • The maximum length of the RADIUS payload is 4096 bytes.

Configure RADIUS Servers for AAA

This section describes how to configure RADIUS servers for AAA.

Procedure

Step 1

Load the ASA attributes into the RADIUS server. The method that you use to load the attributes depends on which type of RADIUS server that you are using:

  • If you are using Cisco ACS: the server already has these attributes integrated. You can skip this step.

  • For RADIUS servers from other vendors (for example, Microsoft Internet Authentication Service): you must manually define each ASA attribute. To define an attribute, use the attribute name or number, type, value, and vendor code (3076).

Step 2

Configure RADIUS Server Groups.

Step 3

Add a RADIUS Server to a Group.

Step 4

(Optional) Add an Authentication Prompt.

Configure RADIUS Server Groups

If you want to use an external RADIUS server for authentication, authorization, or accounting, you must first create at least one RADIUS server group per AAA protocol and add one or more servers to each group.

Procedure

Step 1

Choose Configuration > Device Management > Users/AAA > AAA Server Groups.

Step 2

Click Add in the AAA Server Groups area.

The Add AAA Server Group dialog box appears.

Step 3

Enter a name for the group in the AAA Server Group field.

Step 4

Choose the RADIUS server type from the Protocol drop-down list.

Step 5

Select the Accounting Mode.

  • Simultaneous—Send accounting data to all servers in the group.
  • Single—Send accounting data to only one server.

Step 6

Configure the method (Reactivation Mode) by which failed servers in a group are reactivated.

  • Depletion, Dead Time—Reactivate failed servers only after all of the servers in the group are inactive. This is the default reactivation mode. Specify the amount of time, between 0 and 1440 minutes, that elapses between the disabling of the last server in the group and the subsequent reenabling of all servers. Deadtime applies only if you configure fallback to the local database; authentication is attempted locally until the deadtime elapses. The default is 10 minutes.

  • Timed—Reactivate failed servers after 30 seconds of down time.

Step 7

In Max Failed Attempts, specify the maximum number of failed AAA transactions with a RADIUS server in the group before trying the next server.

The range is from 1 and 5. The default is 3.

If you configure a fallback method using the local database (for management access only), and all the servers in the group fail to respond, or their responses are invalid, then the group is considered to be unresponsive, and the fallback method is tried. The server group remains marked as unresponsive for a period of 10 minutes (if you use the default reactivation mode and dead time), so that additional AAA requests within that period do not attempt to contact the server group, and the fallback method is used immediately. To change the unresponsive period from the default, see change the Dead Time.

If you do not have a fallback method, the ASA continues to retry the servers in the group.

Step 8

(Optional.) Enable the periodic generation of RADIUS interim-accounting-update messages by selecting the desired options.

These options are relevant only if you are using this server group for Secure Client or clientless SSL VPN.

  • Enable interim accounting update—If you use this command without selecting the Update Interval option, the ASA sends interim-accounting-update messages only when a VPN tunnel connection is added to a clientless VPN session. When this happens the accounting update is generated in order to inform the RADIUS server of the newly assigned IP address.

  • Update Interval—Enables the periodic generation and transmission of accounting records for every VPN session that is configured to send accounting records to the server group in question. You can change the interval, in hours, for sending these updates. The default is 24 hours, the range is 1 to 120.

Note

 

For server groups containing ISE servers, select both options. ISE maintains a directory of active sessions based on the accounting records that it receives from NAS devices like the ASA. However, if ISE does not receive any indication that the session is still active (accounting message or posture transactions) for a period of 5 days, it will remove the session record from its database. To ensure that long-lived VPN connections are not removed, configure the group to send periodic interim-accounting-update messages to ISE for all active sessions.

Step 9

(Optional.) If this group contains AD Agents or Cisco Directory Agent (CDA) servers only, select Enable Active Directory Agent Mode.

CDA or AD Agents are used in identity firewall, and are not full-featured RADIUS servers. If you select this option, you can use this group for identity firewall purposes only.

Step 10

(Optional) If you are using this server group for ISE Policy Enforcement in remote access VPN, configure the following options:

  • Enable dynamic authorization—Enable the RADIUS Dynamic Authorization (ISE Change of Authorization, CoA) services for the AAA server group. When you use the server group in a VPN tunnel, the RADIUS server group will be registered for CoA notification and the ASA will listen to the port for the CoA policy updates from ISE. Enable dynamic authorization only if you are using this server group in a remote access VPN in conjunction with ISE.

  • Dynamic Authorization Port—If you enable dynamic authorization, you can specify the listening port for RADIUS CoA requests. The default is 1700. The valid range is 1024 to 65535.

  • Use authorization only mode—If you do not want to use ISE for authentication, enable authorize-only mode for the RADIUS server group. This indicates that when this server group is used for authorization, the RADIUS Access Request message will be built as an “Authorize Only” request as opposed to the configured password methods defined for the AAA server. If you do configure a common password for the RADIUS server, it will be ignored.

    For example, you would use authorize-only mode if you want to use certificates for authentication rather than this server group. You would still use this server group for authorization and accounting in the VPN tunnel.

Step 11

(Optional.) Configure the VPN3K Compatibility Option to specify whether or not a downloadable ACL received from a RADIUS packet should be merged with a Cisco AV pair ACL.

This option applies only to VPN connections. For VPN users, ACLs can be in the form of Cisco AV pair ACLs, downloadable ACLs, and an ACL that is configured on the ASA. This option determines whether or not the downloadable ACL and the AV pair ACL are merged, and does not apply to any ACLs configured on the ASA.

  • Do not merge —Downloadable ACLs will not be merged with Cisco AV pair ACLs. If both an AV pair and a downloadable ACL are received, the AV pair has priority and is used. This is the default option.

  • Place the downloadable ACL after Cisco AV-pair ACL

  • Place the downloadable ACL before Cisco AV-pair ACL

Step 12

Click OK.

The Add AAA Server Group dialog box closes, and the new server group is added to the AAA Server Groups table.

Step 13

Click Apply to save the changes to the running configuration.

Add a RADIUS Server to a Group

To add a RADIUS server to a group, perform the following steps:

Procedure

Step 1

Choose Configuration > Device Management > Users/AAA > AAA Server Groups, and in the AAA Server Groups area, click the server group to which you want to add a server.

Step 2

Click Add in the Servers in the Selected Group area (lower pane).

The Add AAA Server Group dialog box appears for the server group.

Step 3

Choose the interface name on which the authentication server resides.

Step 4

Add either a server name or IP address for the server that you are adding to the group.

Step 5

Specify the timeout value for connection attempts to the server.

Specify the timeout interval (1-300 seconds) for the server; the default is 10 seconds. For each AAA transaction the ASA retries connection attempts (based on the retry interval) until the timeout is reached. If the number of consecutive failed transactions reaches the maximum-failed-attempts limit specified in the AAA server group, the AAA server is deactivated and the ASA starts sending requests to another AAA server if it is configured.

Step 6

Specify how you want the ASA to handle netmasks received in downloadable ACLs. Choose from the following options:

  • Detect automatically—The ASA attempts to determine the type of netmask expression used. If the ASA detects a wildcard netmask expression, the ASA converts it to a standard netmask expression.

    Note

     

    Because some wildcard expressions are difficult to detect clearly, this setting may misinterpret a wildcard netmask expression as a standard netmask expression.

  • Standard—The ASA assumes downloadable ACLs received from the RADIUS server contain only standard netmask expressions. No translation from wildcard netmask expressions is performed.

  • Wildcard—The ASA assumes downloadable ACLs received from the RADIUS server contain only wildcard netmask expressions, and it converts them all to standard netmask expressions when the ACLs are downloaded.

Step 7

Specify a case-sensitive password that is common among users who access this RADIUS authorization server through this ASA. Be sure to provide this information to your RADIUS server administrator.

Note

 

For an authentication RADIUS server (rather than authorization), do not configure a common password.

If you leave this field blank, the username is the password for accessing this RADIUS authorization server.

Never use a RADIUS authorization server for authentication. Common passwords or usernames as passwords are less secure than assigning unique user passwords.

Although the password is required by the RADIUS protocol and the RADIUS server, users do not need to know it.

Step 8

If you use double authentication and enable password management in the tunnel group, then the primary and secondary authentication requests include MS-CHAPv2 request attributes. If a RADIUS server does not support MS-CHAPv2, then you can configure that server to send a non-MS-CHAPv2 authentication request by unchecking this check box.

Step 9

Specify the length of time, from 1 to 10 seconds, that the ASA waits between attempts to contact the server.

Note

 

For the RADIUS protocol, if the server responds with an ICMP Port Unreachable message, the retry-interval setting is ignored and the AAA server is immediately moved to the failed state. If this is the only server in the AAA group, it is reactivated and another request is sent to it. This is the intended behavior.

Step 10

Click Simultaneous or Single.

In Single mode, the ASA sends accounting data to only one server.

In Simultaneous mode, the ASA sends accounting data to all servers in the group.

Step 11

Specify the server port to be used for accounting of users. The default port is 1646.

Step 12

Specify the server port to be used for authentication of users. The default port is 1645.

Step 13

Specify the shared secret key used to authenticate the RADIUS server to the ASA. The server secret that you configure should match the one configured on the RADIUS server. If you do not know the server secret, ask the RADIUS server administrator. The maximum field length is 64 characters.

Step 14

Click OK.

The Add AAA Server Group dialog box closes, and the AAA server is added to the AAA server group.

Step 15

In the AAA Server Groups pane, click Apply to save the changes to the running configuration.

Add an Authentication Prompt

You can specify the AAA challenge text for HTTP, FTP, and Telnet access through the ASA when requiring user authentication from RADIUS servers. This text is primarily for cosmetic purposes and appears above the username and password prompts that users see when they log in. If you do not specify an authentication prompt, users see the following when authenticating with a RADIUS server:

Connection Type

Default Prompt

FTP

FTP authentication

HTTP

HTTP authentication

Telnet

None

To add an authentication prompt, perform the following steps:

Procedure

Step 1

Choose Configuration > Device Management > Users/AAA > Authentication Prompt.

Step 2

Enter text in the Prompt field to add as a message to appear above the username and password prompts that users see when they log in.

The following table shows the allowed character limits for authentication prompts:

Application

Character Limit

Microsoft Internet Explorer

37

Telnet

235

FTP

235

Step 3

Add messages in the User accepted message and User rejected message fields.

If the user authentication occurs from Telnet, you can use the User accepted message and User rejected message options to display different status prompts to indicate that the authentication attempt is either accepted or rejected by the RADIUS server.

If the RADIUS server authenticates the user, the ASA displays the User accepted message text, if specified, to the user; otherwise, the ASA displays the User rejected message text, if specified. Authentication of HTTP and FTP sessions displays only the challenge text at the prompt. The User accepted message and User rejected message text are not displayed.

Step 4

Click Apply to save the changes to the running configuration.

Test RADIUS Server Authentication and Authorization

To determine whether the ASA can contact a RADIUS server and authenticate or authorize a user, perform the following steps:

Procedure

Step 1

Choose Configuration > Device Management > Users/AAA > AAA Server Groups.

Step 2

Click the server group in which the server resides in the AAA Server Groups table.

Step 3

Click the server that you want to test in the Servers in the Selected Group table.

Step 4

Click Test.

The Test AAA Server dialog box appears for the selected server.

Step 5

Click the type of test that you want to perform—Authentication or Authorization.

Step 6

Enter a username.

Step 7

Enter the password for the username if you are testing authentication.

Step 8

Click OK.

The ASA sends an authentication or authorization test message to the server. If the test fails, an error message appears.

Monitoring RADIUS Servers for AAA

See the following commands for monitoring the status of RADIUS servers for AAA:

  • Monitoring > Properties > AAA Servers

    This pane shows the RADIUS server running configuration.

  • Tools > Command Line Interface

    This pane allows you to issue various non-interactive commands and view results.

History for RADIUS Servers for AAA

Table 3. History for RADIUS Servers for AAA

Feature Name

Platform Releases

Description

RADIUS Servers for AAA

7.0(1)

Describes how to configure RADIUS servers for AAA.

We introduced the following screens:

Configuration > Device Management > Users/AAA > AAA Server Groups
Configuration > Device Management > Users/AAA > Authentication Prompt.

Key vendor-specific attributes (VSAs) sent in RADIUS access request and accounting request packets from the ASA

8.4(3)

Four New VSAs—Tunnel Group Name (146) and Client Type (150) are sent in RADIUS access request packets from the ASA. Session Type (151) and Session Subtype (152) are sent in RADIUS accounting request packets from the ASA. All four attributes are sent for all accounting request packet types: Start, Interim-Update, and Stop. The RADIUS server (for example, ACS and ISE) can then enforce authorization and policy attributes or use them for accounting and billing purposes.

Increased limits for AAA server groups and servers per group.

9.13(1)

You can configure more AAA server groups. In single context mode, you can configure 200 AAA server groups (the former limit was 100). In multiple context mode, you can configure 8 (the former limit was 4).

In addition, in multiple context mode, you can configure 8 servers per group (the former limit was 4 servers per group). The single context mode per-group limit of 16 remains unchanged.

We modified the AAA screens to accept these new limits.