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.

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

Create the RADIUS AAA server group.

aaa-server group_name protocol radius

Example:


ciscoasa(config)# aaa-server servergroup1 protocol radius
ciscoasa(config-aaa-server-group)#

When you enter the aaa-server protocol command, you enter aaa-server group configuration mode.

Step 2

(Optional.) Specify the maximum number of failed AAA transactions with a RADIUS server in the group before trying the next server.

max-failed-attempts number

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

If you configured 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 (by default), 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 the reactivation-mode command in the next step.

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

Example:


ciscoasa(config-aaa-server-group)# max-failed-attempts 2

Step 3

(Optional.) Specify the method (reactivation policy) by which failed servers in a group are reactivated.

reactivation-mode {depletion [deadtime minutes] | timed}

Where:

  • depletion [deadtime minutes] reactivates failed servers only after all of the servers in the group are inactive. This is the default reactivation mode. You can 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 reactivates failed servers after 30 seconds of down time.

Example:


ciscoasa(config-aaa-server-group)# reactivation-mode deadtime 20

Step 4

(Optional.) Send accounting messages to all servers in the group.

accounting-mode simultaneous

To restore the default of sending messages only to the active server, enter the accounting-mode single command.

Example:


ciscoasa(config-aaa-server-group)# accounting-mode simultaneous

Step 5

(Optional.) Enable the periodic generation of RADIUS interim-accounting-update messages.

interim-accounting-update [periodic [hours]]

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.

  • periodic [hours] 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 optionally include the interval, in hours, for sending these updates. The default is 24 hours, the range is 1 to 120.

  • (No parameters.) If you use this command without the periodic keyword, 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.

Example:


hostname(config-aaa-server-group)# interim-accounting-update periodic 12

Step 6

(Optional.) Enable the RADIUS Dynamic Authorization (ISE Change of Authorization, CoA) services for the AAA server group.

dynamic-authorization [port number]

Specifying a port is optional. The default is 1700, the range is 1024 to 65535.

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.

Example:


ciscoasa(config-aaa-server-group)# dynamic-authorization

Step 7

(Optional.) If you do not want to use ISE for authentication, enable authorize-only mode for the RADIUS server group. (Enable authorize-only mode only if you are using this server group in a remote access VPN in conjunction with ISE.)

authorize-only

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 using radius-common-pw command 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.

Example:


ciscoasa(config-aaa-server-group)# authorize-only

Step 8

(Optional.) Merge a downloadable ACL with the ACL received in the Cisco AV pair from a RADIUS packet.

merge-dacl {before-avpair | after-avpair}

Example:


ciscoasa(config-aaa-server-group)# merge-dacl before-avpair

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.

The default setting is no merge dacl , which specifies that 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.

The before-avpair option specifies that the downloadable ACL entries should be placed before the Cisco AV pair entries.

The after-avpair option specifies that the downloadable ACL entries should be placed after the Cisco AV pair entries.

Examples

The following example shows how to add one RADIUS group with a single server: 


ciscoasa(config)# aaa-server AuthOutbound protocol radius
ciscoasa(config-aaa-server-group)# exit
ciscoasa(config)# aaa-server AuthOutbound (inside) host 10.1.1.3
ciscoasa(config-aaa-server-host)# key RadUauthKey
ciscoasa(config-aaa-server-host)# exit

The following example shows how to configure an ISE server group for dynamic authorization (CoA) updates and hourly periodic accounting. Included is the tunnel group configuration that configures password authentication with ISE. 


ciscoasa(config)# aaa-server ise protocol radius
ciscoasa(config-aaa-server-group)# interim-accounting-update periodic 1
ciscoasa(config-aaa-server-group)# dynamic-authorization
ciscoasa(config-aaa-server-group)# exit
ciscoasa(config)# aaa-server ise (inside) host 10.1.1.3
ciscoasa(config-aaa-server-host)# key sharedsecret
ciscoasa(config-aaa-server-host)# exit
ciscoasa(config)# tunnel-group aaa-coa general-attributes
ciscoasa(config-tunnel-general)# address-pool vpn
ciscoasa(config-tunnel-general)# authentication-server-group ise
ciscoasa(config-tunnel-general)# accounting-server-group ise
ciscoasa(config-tunnel-general)# exit

The following example shows how to configure a tunnel group for local certificate validation and authorization with ISE. Include the authorize-only command in the server group configuration, because the server group will not be used for authentication. 


ciscoasa(config)# aaa-server ise protocol radius
ciscoasa(config-aaa-server-group)# authorize-only
ciscoasa(config-aaa-server-group)# interim-accounting-update periodic 1
ciscoasa(config-aaa-server-group)# dynamic-authorization
ciscoasa(config-aaa-server-group)# exit
ciscoasa(config)# aaa-server ise (inside) host 10.1.1.3
ciscoasa(config-aaa-server-host)# key sharedsecret
ciscoasa(config-aaa-server-host)# exit
ciscoasa(config)# tunnel-group aaa-coa general-attributes
ciscoasa(config-tunnel-general)# address-pool vpn
ciscoasa(config-tunnel-general)# authentication certificate
ciscoasa(config-tunnel-general)# authorization-server-group ise
ciscoasa(config-tunnel-general)# accounting-server-group ise
ciscoasa(config-tunnel-general)# exit

Add a RADIUS Server to a Group

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

Procedure

Step 1

Identify the RADIUS server and the AAA server group to which it belongs.

aaa-server server_group [(interface_name)] host server_ip

Example:


ciscoasa(config-aaa-server-group)# aaa-server servergroup1 outside host 10.10.1.1

If you do not specify an (interface_name) , then the ASA uses the inside interface by default.

Step 2

Specify how the ASA treats netmasks received in a downloadable ACL from a RADIUS server.

acl-netmask-convert {auto-detect | standard | wildcard}

Example:


ciscoasa(config-aaa-server-host)# acl-netmask-convert standard

Theauto-detect keyword specifies that the ASA should attempt to determine the type of netmask expression used. If the ASA detects a wildcard netmask expression, it converts it to a standard netmask expression.

The standard keyword specifies that the ASA assumes downloadable ACLs received from the RADIUS server contain only standard netmask expressions. No translation from wildcard netmask expressions is performed.

The wildcard keyword specifies that the ASA assumes downloadable ACLs received from the RADIUS server contain only wildcard netmask expressions and converts them all to standard netmask expressions when the ACLs are downloaded.

Step 3

Specify a common password to be used for all users who are accessing a RADIUS authorization server through the ASA.

radius-common-pw string

Example:


ciscoasa(config-aaa-server-host)# radius-common-pw examplepassword123abc

The string argument is a case-sensitive, alphanumeric keyword of up to 127 characters to be used as a common password for all authorization transactions with the RADIUS server.

Step 4

Enable MS-CHAPv2 authentication requests to the RADIUS server.

mschapv2-capable

Example:


ciscoasa(config-aaa-server-host)# mschapv2-capable

Step 5

Specify the timeout value for connection attempts to the server.

timeout seconds

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 interval defined on the retry-interval command) until the timeout is reached. If the number of consecutive failed transactions reaches the limit specified on the max-failed-attempts command in the AAA server group, the AAA server is deactivated and the ASA starts sending requests to another AAA server if it is configured.

Example:


ciscoasa(config-aaa-server-host)# timeout 15

Step 6

Configure the amount of time between retry attempts for a particular AAA server designated in a previous command.

retry-interval seconds

Example:


ciscoasa(config-aaa-server-host)# retry-interval 8

The seconds argument specifies the retry interval (1-10 seconds) for the request. This is the time that the ASA waits before retrying a connection request.

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 7

Send accounting messages to all servers in the group.

accounting-mode simultaneous

Example:


ciscoasa(config-aaa-server-group)# accounting-mode simultaneous

Enter the accounting-mode single command to restore the default of sending messages only to the active server.

Step 8

Specify the authentication port as port number1645, or the server port to be used for authentication of users.

authentication-port port

Example:


ciscoasa(config-aaa-server-host)# authentication-port 1646

Step 9

Specify the accounting port as port number 1646, or the server port to be used for accounting for this host.

accounting-port port

Example:


ciscoasa(config-aaa-server-host)# accounting-port 1646

Step 10

Specify the server secret value 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 value, ask the RADIUS server administrator. The maximum length is 64 characters.

key

Example:


ciscoasa(config-aaa-host)# key myexamplekey1

The server secret that you configure should match the one configured on the RADIUS server. If you do not know the server secret value, ask the RADIUS server administrator. The maximum length is 64 characters.

Example

The following example shows how to add a RADIUS server to an existing RADIUS server group: 


ciscoasa(config)# aaa-server svrgrp1 protocol radius
ciscoasa(config-aaa-server-group)# aaa-server svrgrp1 host 192.168.3.4
ciscoasa(config-aaa-server-host)# acl-netmask-convert wildcard
ciscoasa(config-aaa-server-host)# radius-common-pw myexaplepasswordabc123
ciscoasa(config-aaa-server-host)# mschapv2-capable
ciscoasa(config-aaa-server-host)# timeout 9
ciscoasa(config-aaa-server-host)# retry-interval 7
ciscoasa(config-aaa-server-host)# accounting-mode simultaneous
ciscoasa(config-aaa-server-host)# authentication-port 1650
ciscoasa(config-aaa-server-host)# authorization-port 1645
ciscoasa(config-aaa-server-host)# key mysecretkeyexampleiceage2
ciscoasa(config-aaa-server-host)# exit
ciscoasa(config)#

Monitoring RADIUS Servers for AAA

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

  • show aaa-server

    This command shows the configured RADIUS server statistics. You can use the clear aaa-server statistics command to reset the counters to zero.

  • show running-config aaa-server

    This command shows the RADIUS server running configuration.

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 commands:

aaa-server protocol, max-failed-attempts, reactivation-mode, accounting-mode simultaneous, aaa-server host, show aaa-server, show running-config aaa-server, clear aaa-server statistics, authentication-port, accounting-port, retry-interval, acl-netmask-convert, clear configure aaa-server, merge-dacl, radius-common-pw, key.

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 following commands to accept these new limits: aaa-server , aaa-server host .