Table Of Contents

Administering the Access Point/Bridge

Preventing Unauthorized Access to Your Access Point/Bridge

Protecting Access to Privileged EXEC Commands

Default Password and Privilege Level Configuration

Setting or Changing a Static Enable Password

Protecting Enable and Enable Secret Passwords with Encryption

Configuring Username and Password Pairs

Configuring Multiple Privilege Levels

Setting the Privilege Level for a Command

Logging Into and Exiting a Privilege Level

Controlling Access Point/Bridge Access with RADIUS

Default RADIUS Configuration

Configuring RADIUS Login Authentication

Defining AAA Server Groups

Configuring RADIUS Authorization for User Privileged Access and Network Services

Displaying the RADIUS Configuration

Controlling Access Point/Bridge Access with TACACS+

Default TACACS+ Configuration

Configuring TACACS+ Login Authentication

Configuring TACACS+ Authorization for Privileged EXEC Access and Network Services

Displaying the TACACS+ Configuration

Configuring Ethernet Speed and Duplex Settings

Configuring the Access Point/Bridge for Local Authentication and Authorization

Configuring the Authentication Cache and Profile

Configuring the Access Point/Bridge to Provide DHCP Service

Setting up the DHCP Server

Monitoring and Maintaining the DHCP Server Access Point

Show Commands

Clear Commands

Debug Command

Configuring the Access Point for Secure Shell

Understanding SSH

Configuring SSH

Configuring Client ARP Caching

Understanding Client ARP Caching

Optional ARP Caching

Configuring ARP Caching

Managing the System Time and Date

Understanding the System Clock

Understanding Network Time Protocol

Configuring NTP

Default NTP Configuration

Configuring NTP Authentication

Configuring NTP Associations

Configuring NTP Broadcast Service

Configuring NTP Access Restrictions

Configuring the Source IP Address for NTP Packets

Displaying the NTP Configuration

Configuring Time and Date Manually

Setting the System Clock

Displaying the Time and Date Configuration

Configuring the Time Zone

Configuring Summer Time (Daylight Saving Time)

Configuring a System Name and Prompt

Default System Name and Prompt Configuration

Configuring a System Name

Understanding DNS

Default DNS Configuration

Setting Up DNS

Displaying the DNS Configuration

Creating a Banner

Default Banner Configuration

Configuring a Message-of-the-Day Login Banner

Configuring a Login Banner

Administering the Access Point/Bridge

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This chapter describes how to administer your access point/bridge. This chapter contains these sections:

•Preventing Unauthorized Access to Your Access Point/Bridge

•Protecting Access to Privileged EXEC Commands

•Controlling Access Point/Bridge Access with RADIUS

•Controlling Access Point/Bridge Access with TACACS+

•Configuring Ethernet Speed and Duplex Settings

•Configuring the Access Point/Bridge for Local Authentication and Authorization

•Configuring the Authentication Cache and Profile

•Configuring Client ARP Caching

•Configuring Client ARP Caching

•Managing the System Time and Date

•Configuring a System Name and Prompt

•Creating a Banner

Preventing Unauthorized Access to Your Access Point/Bridge

You can prevent unauthorized users from reconfiguring your access point/bridge and viewing configuration information. Typically, you want network administrators to have access to the access point/bridge while you restrict access to users who connect through a terminal or workstation from within the local network.

To prevent unauthorized access to your access point/bridge, you should configure one of these security features:

•Username and password pairs, which are locally stored on the access point/bridge. These pairs authenticate each user before that user can access the access point/bridge. You can also assign a specific privilege level (read only or read/write) to each username and password pair. For more information, see the "Configuring Username and Password Pairs" section.

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Note The default username is Cisco, and the default password is Cisco.
Usernames and passwords are case-sensitive.

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•Username and password pairs stored centrally in a database on a security server. For more information, see the "Controlling Access Point/Bridge Access with RADIUS" section.

Protecting Access to Privileged EXEC Commands

A simple way of providing terminal access control in your network is to use passwords and assign privilege levels. Password protection restricts access to a network or network device. Privilege levels define what commands users can issue after they have logged into a network device.

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Note For complete syntax and usage information for the commands used in this section, refer to the Cisco IOS Security Command Reference for Release 12.2.

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This section describes how to control access to the configuration file and privileged EXEC commands. It contains this configuration information:

•Default Password and Privilege Level Configuration

•Setting or Changing a Static Enable Password

•Protecting Enable and Enable Secret Passwords with Encryption

•Configuring Username and Password Pairs

•Configuring Multiple Privilege Levels

Default Password and Privilege Level Configuration

Table 5-1 shows the default password and privilege level configuration.

Table 5-1 Default Password and Privilege Levels 

Feature	Default Setting
Username and password	Default username is Cisco and the default password is Cisco.
Enable password and privilege level	Default password is Cisco. The default is level 15 (privileged EXEC level). The password is encrypted in the configuration file.
Enable secret password and privilege level	The default enable password is Cisco. The default is level 15 (privileged EXEC level). The password is encrypted before it is written to the configuration file.
Line password	Default password is Cisco. The password is encrypted in the configuration file.

Setting or Changing a Static Enable Password

The enable password controls access to the privileged EXEC mode.

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Note The no enable password global configuration command removes the enable password, but you should use extreme care when using this command. If you remove the enable password, you are locked out of the EXEC mode.

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Beginning in privileged EXEC mode, follow these steps to set or change a static enable password:

	Command	Purpose
Step 1	configure terminal	Enter global configuration mode.
Step 2	enable password password	Define a new password or change an existing password for access to privileged EXEC mode. The default password is Cisco. For password, specify a string from 1 to 25 alphanumeric characters. The string cannot start with a number, is case sensitive, and allows spaces but ignores leading spaces. It can contain the question mark (?) character if you precede the question mark with the key combination Crtl-V when you create the password; for example, to create the password abc?123, do this: 1. Enter abc. 2. Enter Crtl-V. 3. Enter ?123. When the system prompts you to enter the enable password, you need not precede the question mark with the Ctrl-V; you can simply enter abc?123 at the password prompt.
Step 3	end	Return to privileged EXEC mode.
Step 4	show running-config	Verify your entries.
Step 5	copy running-config startup-config	(Optional) Save your entries in the configuration file. The enable password is not encrypted and can be read in the access point/bridge configuration file.

This example shows how to change the enable password to l1u2c3k4y5. The password is not encrypted and provides access to level 15 (traditional privileged EXEC mode access):

bridge(config)# enable password l1u2c3k4y5

Protecting Enable and Enable Secret Passwords with Encryption

To provide an additional layer of security, particularly for passwords that cross the network or that are stored on a Trivial File Transfer Protocol (TFTP) server, you can use either the enable password or enable secret global configuration commands. Both commands accomplish the same thing; that is, you can establish an encrypted password that users must enter to access privileged EXEC mode (the default) or any privilege level you specify.

We recommend that you use the enable secret command because it uses an improved encryption algorithm.

If you configure the enable secret command, it takes precedence over the enable password command; the two commands cannot be in effect simultaneously.

Beginning in privileged EXEC mode, follow these steps to configure encryption for enable and enable secret passwords:

	Command	Purpose
Step 1	configure terminal	Enter global configuration mode.
Step 2	enable password [level level] {password | encryption-type encrypted-password} or enable secret [level level] {password | encryption-type encrypted-password}	Define a new password or change an existing password for access to privileged EXEC mode. or Define a secret password, which is saved using a nonreversible encryption method. •(Optional) For level, the range is from 0 to 15. Level 1 is normal user EXEC mode privileges. The default level is 15 (privileged EXEC mode privileges). •For password, specify a string from 1 to 25 alphanumeric characters. The string cannot start with a number, is case sensitive, and allows spaces but ignores leading spaces. By default, no password is defined. •(Optional) For encryption-type, only type 5, a Cisco proprietary encryption algorithm, is available. If you specify an encryption type, you must provide an encrypted password—an encrypted password you copy from another access point/bridge configuration. Note If you specify an encryption type and then enter a clear text password, you can not re-enter privileged EXEC mode. You cannot recover a lost encrypted password by any method.
Step 3	service password-encryption	(Optional) Encrypt the password when the password is defined or when the configuration is written. Encryption prevents the password from being readable in the configuration file.
Step 4	end	Return to privileged EXEC mode.
Step 5	copy running-config startup-config	(Optional) Save your entries in the configuration file.

If both the enable and enable secret passwords are defined, users must enter the enable secret password.

Use the level keyword to define a password for a specific privilege level. After you specify the level and set a password, give the password only to users who need to have access at this level. Use the privilege level global configuration command to specify commands accessible at various levels. For more information, see the "Configuring Multiple Privilege Levels" section.

If you enable password encryption, it applies to all passwords including username passwords, authentication key passwords, the privileged command password, and console and virtual terminal line passwords.

To remove a password and level, use the no enable password [level level] or no enable secret [level level] global configuration command. To disable password encryption, use the no service password-encryption global configuration command.

This example shows how to configure the encrypted password $1$FaD0$Xyti5Rkls3LoyxzS8 for privilege level 2:

ap(config)# enable secret level 2 5 $1$FaD0$Xyti5Rkls3LoyxzS8

Configuring Username and Password Pairs

You can configure username and password pairs, which are locally stored on the access point/bridge. These pairs are assigned to lines or interfaces and authenticate each user before that user can access the access point/bridge. If you have defined privilege levels, you can also assign a specific privilege level (with associated rights and privileges) to each username and password pair.

Beginning in privileged EXEC mode, follow these steps to establish a username-based authentication system that requests a login username and a password:

	Command	Purpose
Step 1	configure terminal	Enter global configuration mode.
Step 2	username name [privilege level] {password encryption-type password}	Enter the username, privilege level, and password for each user. •For name, specify the user ID as one word. Spaces and quotation marks are not allowed. •(Optional) For level, specify the privilege level the user has after gaining access. The range is 0 to 15. Level 15 gives privileged EXEC mode access. Level 1 gives user EXEC mode access. •For encryption-type, enter 0 to specify that an unencrypted password will follow. Enter 7 to specify that a hidden password will follow. •For password, specify the password the user must enter to gain access to the access point/bridge. The password must be from 1 to 25 characters, can contain embedded spaces, and must be the last option specified in the username command.
Step 3	login local	Enable local password checking at login time. Authentication is based on the username specified in Step 2.
Step 4	end	Return to privileged EXEC mode.
Step 5	show running-config	Verify your entries.
Step 6	copy running-config startup-config	(Optional) Save your entries in the configuration file.

To disable username authentication for a specific user, use the no username name global configuration command.

To disable password checking and allow connections without a password, use the no login line configuration command.

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Note You must have at least one username configured and you must have login local set to open a Telnet session to the access point/bridge. If you enter no username for the only username, you can be locked out of the access point/bridge.

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Configuring Multiple Privilege Levels

By default, Cisco IOS software has two modes of password security: user EXEC and privileged EXEC. You can configure up to 16 hierarchical levels of commands for each mode. By configuring multiple passwords, you can allow different sets of users to have access to specified commands.

For example, if you want many users to have access to the clear line command, you can assign it level 2 security and distribute the level 2 password fairly widely. But if you want more restricted access to the configure command, you can assign it level 3 security and distribute that password to a more restricted group of users.

This section includes this configuration information:

•Setting the Privilege Level for a Command

•Logging Into and Exiting a Privilege Level

Setting the Privilege Level for a Command

Beginning in privileged EXEC mode, follow these steps to set the privilege level for a command mode:

	Command	Purpose
Step 1	configure terminal	Enter global configuration mode.
Step 2	privilege mode level level command	Set the privilege level for a command. •For mode, enter configure for global configuration mode, exec for EXEC mode, interface for interface configuration mode, or line for line configuration mode. •For level, the range is from 0 to 15. Level 1 is for normal user EXEC mode privileges. Level 15 is the level of access permitted by the enable password. •For command, specify the command to which you want to restrict access.
Step 3	enable password level level password	Specify the enable password for the privilege level. •For level, the range is from 0 to 15. Level 1 is for normal user EXEC mode privileges. •For password, specify a string from 1 to 25 alphanumeric characters. The string cannot start with a number, is case sensitive, and allows spaces but ignores leading spaces. By default, no password is defined.
Step 4	end	Return to privileged EXEC mode.
Step 5	show running-config or show privilege	Verify your entries. The first command displays the password and access level configuration. The second command displays the privilege level configuration.
Step 6	copy running-config startup-config	(Optional) Save your entries in the configuration file.

When you set a command to a privilege level, all commands whose syntax is a subset of that command are also set to that level. For example, if you set the show ip route command to level 15, the show commands and show ip commands are automatically set to privilege level 15 unless you set them individually to different levels.

To return to the default privilege for a given command, use the no privilege mode level level command global configuration command.

This example shows how to set the configure command to privilege level 14 and define SecretPswd14 as the password users must enter to use level 14 commands:

ap(config)# privilege exec level 14 configure

ap(config)# enable password level 14 SecretPswd14

Logging Into and Exiting a Privilege Level

Beginning in privileged EXEC mode, follow these steps to log in to a specified privilege level and to exit to a specified privilege level:

	Command	Purpose
Step 1	enable level	Log in to a specified privilege level. For level, the range is 0 to 15.
Step 2	disable level	Exit to a specified privilege level. For level, the range is 0 to 15.

Controlling Access Point/Bridge Access with RADIUS

This section describes how to control administrator access to the access point/bridge using Remote Authentication Dial-In User Service (RADIUS). For complete instructions on configuring the access point/bridge to support RADIUS, see "Configuring RADIUS and TACACS+ Servers."

RADIUS provides detailed accounting information and flexible administrative control over authentication and authorization processes. RADIUS is facilitated through AAA and can be enabled only through AAA commands.

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Note For complete syntax and usage information for the commands used in this section, refer to the Cisco IOS Security Command Reference for Release 12.2.

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These sections describe RADIUS configuration:

•Default RADIUS Configuration

•Configuring RADIUS Login Authentication (required)

•Defining AAA Server Groups (optional)

•Configuring RADIUS Authorization for User Privileged Access and Network Services (optional)

•Displaying the RADIUS Configuration

Default RADIUS Configuration

RADIUS and AAA are disabled by default.

To prevent a lapse in security, you cannot configure RADIUS through a network management application. When enabled, RADIUS can authenticate users accessing the access point/bridge through the CLI.

Configuring RADIUS Login Authentication

To configure AAA authentication, you define a named list of authentication methods and then apply that list to various interfaces. The method list defines the types of authentication to be performed and the sequence in which they are performed; it must be applied to a specific interface before any of the defined authentication methods are performed. The only exception is the default method list (which, by coincidence, is named default). The default method list is automatically applied to all interfaces except those that have a named method list explicitly defined.

A method list describes the sequence and authentication methods to be queried to authenticate a user. You can designate one or more security protocols to be used for authentication, thus ensuring a backup system for authentication in case the initial method fails. The software uses the first method listed to authenticate users; if that method fails to respond, the software selects the next authentication method in the method list. This process continues until there is successful communication with a listed authentication method or until all defined methods are exhausted. If authentication fails at any point in this cycle—meaning that the security server or local username database responds by denying the user access—the authentication process stops, and no other authentication methods are attempted.

Beginning in privileged EXEC mode, follow these steps to configure login authentication. This procedure is required.

	Command	Purpose
Step 1	configure terminal	Enter global configuration mode.
Step 2	aaa new-model	Enable AAA.
Step 3	aaa authentication login {default | list-name} method1 [method2...]	Create a login authentication method list. •To create a default list that is used when a named list is not specified in the login authentication command, use the default keyword followed by the methods that are to be used in default situations. The default method list is automatically applied to all interfaces. •For list-name, specify a character string to name the list you are creating. •For method1..., specify the actual method the authentication algorithm tries. The additional methods of authentication are used only if the previous method returns an error, not if it fails. Select one of these methods: •local—Use the local username database for authentication. You must enter username information in the database. Use the username password global configuration command. •radius—Use RADIUS authentication. You must configure the RADIUS server before you can use this authentication method. For more information, see the "Identifying the RADIUS Server Host" section.
Step 4	line [console | tty | vty] line-number [ending-line-number]	Enter line configuration mode, and configure the lines to which you want to apply the authentication list.
Step 5	login authentication {default | list-name}	Apply the authentication list to a line or set of lines. •If you specify default, use the default list created with the aaa authentication login command. •For list-name, specify the list created with the aaa authentication login command.
Step 6	end	Return to privileged EXEC mode.
Step 7	show running-config	Verify your entries.
Step 8	copy running-config startup-config	(Optional) Save your entries in the configuration file.

To disable AAA, use the no aaa new-model global configuration command. To disable AAA authentication, use the no aaa authentication login {default | list-name} method1 [method2...] global configuration command. To either disable RADIUS authentication for logins or to return to the default value, use the no login authentication {default | list-name} line configuration command.

Defining AAA Server Groups

You can configure the access point/bridge to use AAA server groups to group existing server hosts for authentication. You select a subset of the configured server hosts and use them for a particular service. The server group is used with a global server-host list, which lists the IP addresses of the selected server hosts.

Server groups also can include multiple host entries for the same server if each entry has a unique identifier (the combination of the IP address and UDP port number), allowing different ports to be individually defined as RADIUS hosts providing a specific AAA service. If you configure two different host entries on the same RADIUS server for the same service (such as accounting), the second configured host entry acts as a fail-over backup to the first one.

You use the server group server configuration command to associate a particular server with a defined group server. You can either identify the server by its IP address or identify multiple host instances or entries by using the optional auth-port and acct-port keywords.

Beginning in privileged EXEC mode, follow these steps to define the AAA server group and associate a particular RADIUS server with it:

	Command	Purpose
Step 1	configure terminal	Enter global configuration mode.
Step 2	aaa new-model	Enable AAA.
Step 3	radius-server host {hostname | ip-address} [auth-port port-number] [acct-port port-number] [timeout seconds] [retransmit retries] [key string]	Specify the IP address or host name of the remote RADIUS server host. •(Optional) For auth-port port-number, specify the UDP destination port for authentication requests. •(Optional) For acct-port port-number, specify the UDP destination port for accounting requests. •(Optional) For timeout seconds, specify the time interval that the access point/bridge waits for the RADIUS server to reply before retransmitting. The range is 1 to 1000. This setting overrides the radius-server timeout global configuration command setting. If no timeout is set with the radius-server host command, the setting of the radius-server timeout command is used. •(Optional) For retransmit retries, specify the number of times a RADIUS request is resent to a server if that server is not responding or responding slowly. The range is 1 to 1000. If no retransmit value is set with the radius-server host command, the setting of the radius-server retransmit global configuration command is used. •(Optional) For key string, specify the authentication and encryption key used between the access point/bridge and the RADIUS daemon running on the RADIUS server. Note The key is a text string that must match the encryption key used on the RADIUS server. Always configure the key as the last item in the radius-server host command. Leading spaces are ignored, but spaces within and at the end of the key are used. If you use spaces in your key, do not enclose the key in quotation marks unless the quotation marks are part of the key. To configure the access point/bridge to recognize more than one host entry associated with a single IP address, enter this command as many times as necessary, making sure that each UDP port number is different. The access point/bridge software searches for hosts in the order in which you specify them. Set the timeout, retransmit, and encryption key values to use with the specific RADIUS host.
Step 4	aaa group server radius group-name	Define the AAA server-group with a group name. This command puts the access point/bridge in a server group configuration mode.
Step 5	server ip-address	Associate a particular RADIUS server with the defined server group. Repeat this step for each RADIUS server in the AAA server group. Each server in the group must be previously defined in Step 2.
Step 6	end	Return to privileged EXEC mode.
Step 7	show running-config	Verify your entries.
Step 8	copy running-config startup-config	(Optional) Save your entries in the configuration file.
Step 9		Enable RADIUS login authentication. See the "Configuring RADIUS Login Authentication" section.

To remove the specified RADIUS server, use the no radius-server host hostname | ip-address global configuration command. To remove a server group from the configuration list, use the no aaa group server radius group-name global configuration command. To remove the IP address of a RADIUS server, use the no server ip-address server group configuration command.

In this example, the access point/bridge is configured to recognize two different RADIUS group servers (group1 and group2). Group1 has two different host entries on the same RADIUS server configured for the same services. The second host entry acts as a fail-over backup to the first entry.

apap(config)# aaa new-model

ap(config)# radius-server host 172.20.0.1 auth-port 1000 acct-port 1001

ap(config)# radius-server host 172.10.0.1 auth-port 1645 acct-port 1646

ap(config)# aaa group server radius group1

ap(config-sg-radius)# server 172.20.0.1 auth-port 1000 acct-port 1001

ap(config-sg-radius)# exit

ap(config)# aaa group server radius group2

ap(config-sg-radius)# server 172.20.0.1 auth-port 2000 acct-port 2001

ap(config-sg-radius)# exit

Configuring RADIUS Authorization for User Privileged Access and Network Services

AAA authorization limits the services available to a user. When AAA authorization is enabled, the access point/bridge uses information retrieved from the user's profile, which is in the local user database or on the security server, to configure the user's session. The user is granted access to a requested service only if the information in the user profile allows it.

You can use the aaa authorization global configuration command with the radius keyword to set parameters that restrict a user's network access to privileged EXEC mode.

The aaa authorization exec radius local command sets these authorization parameters:

•Use RADIUS for privileged EXEC access authorization if authentication was performed by using RADIUS.

•Use the local database if authentication was not performed by using RADIUS.

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Note Authorization is bypassed for authenticated users who log in through the CLI even if authorization has been configured.

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Beginning in privileged EXEC mode, follow these steps to specify RADIUS authorization for privileged EXEC access and network services:

	Command	Purpose
Step 1	configure terminal	Enter global configuration mode.
Step 2	aaa authorization network radius	Configure the access point/bridge for user RADIUS authorization for all network-related service requests.
Step 3	aaa authorization exec radius	Configure the access point/bridge for user RADIUS authorization to determine if the user has privileged EXEC access. The exec keyword might return user profile information (such as autocommand information).
Step 4	end	Return to privileged EXEC mode.
Step 5	show running-config	Verify your entries.
Step 6	copy running-config startup-config	(Optional) Save your entries in the configuration file.

To disable authorization, use the no aaa authorization {network | exec} method1 global configuration command.

Displaying the RADIUS Configuration

To display the RADIUS configuration, use the show running-config privileged EXEC command.

Controlling Access Point/Bridge Access with TACACS+

This section describes how to control administrator access to the access point/bridge using Terminal Access Controller Access Control System Plus (TACACS+). For complete instructions on configuring the access point/bridge to support TACACS+, see "Configuring RADIUS and TACACS+ Servers."

TACACS+ provides detailed accounting information and flexible administrative control over authentication and authorization processes. TACACS+ is facilitated through AAA and can be enabled only through AAA commands.

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Note For complete syntax and usage information for the commands used in this section, refer to the Cisco IOS Security Command Reference for Release 12.2.

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These sections describe TACACS+ configuration:

•Default TACACS+ Configuration

•Configuring TACACS+ Login Authentication

•Configuring TACACS+ Authorization for Privileged EXEC Access and Network Services

•Displaying the TACACS+ Configuration

Default TACACS+ Configuration

TACACS+ and AAA are disabled by default.

To prevent a lapse in security, you cannot configure TACACS+ through a network management application.When enabled, TACACS+ can authenticate administrators accessing the access point/bridge through the CLI.

Configuring TACACS+ Login Authentication

To configure AAA authentication, you define a named list of authentication methods and then apply that list to various interfaces. The method list defines the types of authentication to be performed and the sequence in which they are performed; it must be applied to a specific interface before any of the defined authentication methods are performed. The only exception is the default method list (which, by coincidence, is named default). The default method list is automatically applied to all interfaces except those that have a named method list explicitly defined. A defined method list overrides the default method list.

A method list describes the sequence and authentication methods to be queried to authenticate a user. You can designate one or more security protocols to be used for authentication, thus ensuring a backup system for authentication in case the initial method fails. The software uses the first method listed to authenticate users; if that method fails, the software selects the next authentication method in the method list. This process continues until there is successful communication with a listed authentication method or until all defined methods are exhausted. If authentication fails at any point in this cycle—meaning that the security server or local username database responds by denying the user access—the authentication process stops, and no other authentication methods are attempted.

Beginning in privileged EXEC mode, follow these steps to configure login authentication. This procedure is required.

	Command	Purpose
Step 1	configure terminal	Enter global configuration mode.
Step 2	aaa new-model	Enable AAA.
Step 3	aaa authentication login {default | list-name} method1 [method2...]	Create a login authentication method list. •To create a default list that is used when a named list is not specified in the login authentication command, use the default keyword followed by the methods that are to be used in default situations. The default method list is automatically applied to all interfaces. •For list-name, specify a character string to name the list you are creating. •For method1..., specify the actual method the authentication algorithm tries. The additional methods of authentication are used only if the previous method returns an error, not if it fails. Select one of these methods: •local—Use the local username database for authentication. You must enter username information into the database. Use the username password global configuration command. •tacacs+—Use TACACS+ authentication. You must configure the TACACS+ server before you can use this authentication method.
Step 4	line [console | tty | vty] line-number [ending-line-number]	Enter line configuration mode, and configure the lines to which you want to apply the authentication list.
Step 5	login authentication {default | list-name}	Apply the authentication list to a line or set of lines. •If you specify default, use the default list created with the aaa authentication login command. •For list-name, specify the list created with the aaa authentication login command.
Step 6	end	Return to privileged EXEC mode.
Step 7	show running-config	Verify your entries.
Step 8	copy running-config startup-config	(Optional) Save your entries in the configuration file.

To disable AAA, use the no aaa new-model global configuration command. To disable AAA authentication, use the no aaa authentication login {default | list-name} method1 [method2...] global configuration command. To either disable TACACS+ authentication for logins or to return to the default value, use the no login authentication {default | list-name} line configuration command.

Configuring TACACS+ Authorization for Privileged EXEC Access and Network Services

AAA authorization limits the services available to a user. When AAA authorization is enabled, the access point/bridge uses information retrieved from the user's profile, which is located either in the local user database or on the security server, to configure the user's session. The user is granted access to a requested service only if the information in the user profile allows it.

You can use the aaa authorization global configuration command with the tacacs+ keyword to set parameters that restrict a user's network access to privileged EXEC mode.

The aaa authorization exec tacacs+ local command sets these authorization parameters:

•Use TACACS+ for privileged EXEC access authorization if authentication was performed by using TACACS+.

•Use the local database if authentication was not performed by using TACACS+.

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Note Authorization is bypassed for authenticated users who log in through the CLI even if authorization has been configured.

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Beginning in privileged EXEC mode, follow these steps to specify TACACS+ authorization for privileged EXEC access and network services:

	Command	Purpose
Step 1	configure terminal	Enter global configuration mode.
Step 2	aaa authorization network tacacs+	Configure the access point/bridge for user TACACS+ authorization for all network-related service requests.
Step 3	aaa authorization exec tacacs+	Configure the access point/bridge for user TACACS+ authorization to determine if the user has privileged EXEC access. The exec keyword might return user profile information (such as autocommand information).
Step 4	end	Return to privileged EXEC mode.
Step 5	show running-config	Verify your entries.
Step 6	copy running-config startup-config	(Optional) Save your entries in the configuration file.

To disable authorization, use the no aaa authorization {network | exec} method1 global configuration command.

Displaying the TACACS+ Configuration

To display TACACS+ server statistics, use the show tacacs privileged EXEC command.

Configuring Ethernet Speed and Duplex Settings

The access point/bridge power injector contains an embedded 10/100baseT switch, which is unconfigurable. The ports on the switch are set for auto-speed and auto-duplex, and auto-MDIX. Port 0 on the switch is used for the coaxial link to the bridge; port 1 on the switch is used for the RJ-45 jack on the power injector. The other switch ports are unused.

The speed and duplex settings on the bridge FastEthernet0 interface only apply to the link between the bridge port and port 0 in the power injector switch. They are entirely independent of the speed/duplex used on the RJ-45 port on the power injector. Therefore, for best performance, the bridge FastEthernet must always be set to auto speed and auto duplex. This setting results in 100 Mbps, full duplex used on the link between the bridge and power injector.

The Fast Ethernet Settings page contains the following caution:

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Caution Do not modify the `Requested Duple' or `Requested Speed' while using inline power. Changing these settings while using inline power may cause the device to reboot. See documentation for details.

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The following guidelines for setting Ethernet speed and duplex should always be observed:

•The internal FastEthernet0 interface should always be set for speed auto and duplex auto regardless of the settings of the device to which the external LAN port on the power injector is connected (the connecting port).

•The connecting port should always be set for one of the following:

–100 Mbps, auto duplex (recommended)

–100 Mbps, half duplex

–10 Mbps, auto duplex

–10 Mbps, half duplex

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Note Setting the port to 10 Mbps will most likely degrade throughput.

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•The connecting port should never be set to full duplex.

Failure to follow these guidelines will result in lost data due to late collisions, CRC errors, etc.

Configuring the Access Point/Bridge for Local Authentication and Authorization

You can configure AAA to operate without a server by setting the access point/bridge to implement AAA in local mode. The access point/bridge then handles authentication and authorization. No accounting is available in this configuration.

Beginning in privileged EXEC mode, follow these steps to configure the access point/bridge for local AAA:

	Command	Purpose
Step 1	configure terminal	Enter global configuration mode.
Step 2	aaa new-model	Enable AAA.
Step 3	aaa authentication login default local	Set the login authentication to use the local username database. The default keyword applies the local user database authentication to all interfaces.
Step 4	aaa authorization exec local	Configure user AAA authorization to determine if the user is allowed to run an EXEC shell by checking the local database.
Step 5	aaa authorization network local	Configure user AAA authorization for all network-related service requests.
Step 6	username name [privilege level] {password encryption-type password}	Enter the local database, and establish a username-based authentication system. Repeat this command for each user. •For name, specify the user ID as one word. Spaces and quotation marks are not allowed. •(Optional) For level, specify the privilege level the user has after gaining access. The range is 0 to 15. Level 15 gives privileged EXEC mode access. Level 0 gives user EXEC mode access. •For encryption-type, enter 0 to specify that an unencrypted password follows. Enter 7 to specify that a hidden password follows. •For password, specify the password the user must enter to gain access to the access point/bridge. The password must be from 1 to 25 characters, can contain embedded spaces, and must be the last option specified in the username command.
Step 7	end	Return to privileged EXEC mode.
Step 8	show running-config	Verify your entries.
Step 9	copy running-config startup-config	(Optional) Save your entries in the configuration file.

To disable AAA, use the no aaa new-model global configuration command. To disable authorization, use the no aaa authorization {network | exec} method1 global configuration command.

Configuring the Authentication Cache and Profile

The authentication cache and profile feature allows the access point/bridge to cache the authentication/authorization responses for a user so that subsequent authentication/authorization requests do not need to be sent to the AAA server.

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Note On the access point/bridge, this feature is only supported for Admin authentication.

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The following commands that support this feature are included in Release 12.3(7):

cache expiry

cache authorization profile

cache authentication profile

aaa cache profile

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Note See the Cisco IOS Command Reference for Cisco Aironet Access Points and Bridges, 12.3(7)JA for information about these commands.

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The following is an example configuration from an access point configured for Admin authentication using TACACS+ with the auth cache enabled. While this example is based on a TACACS server, the access point could be configured for Admin authentication using RADIUS:

version 12.3 
no service pad 
service timestamps debug datetime msec 
service timestamps log datetime msec 
service password-encryption 
! 
hostname ap 
! 
! 
username Cisco password 7 123A0C041104 
username admin privilege 15 password 7 01030717481C091D25 
ip subnet-zero 
! 
! 
aaa new-model 
! 
! 
aaa group server radius rad_eap 
server 192.168.134.229 auth-port 1645 acct-port 1646 
! 
aaa group server radius rad_mac 
server 192.168.134.229 auth-port 1645 acct-port 1646 
! 
aaa group server radius rad_acct 
server 192.168.134.229 auth-port 1645 acct-port 1646 
! 
aaa group server radius rad_admin 
server 192.168.134.229 auth-port 1645 acct-port 1646 
cache expiry 1 
cache authorization profile admin_cache 
cache authentication profile admin_cache 
! 
aaa group server tacacs+ tac_admin 
server 192.168.133.231 
cache expiry 1 
cache authorization profile admin_cache 
cache authentication profile admin_cache 
! 
aaa group server radius rad_pmip 
! 
aaa group server radius dummy 
! 
aaa authentication login default local cache tac_admin group tac_admin 
aaa authentication login eap_methods group rad_eap 
aaa authentication login mac_methods local 
aaa authorization exec default local cache tac_admin group tac_admin  
aaa accounting network acct_methods start-stop group rad_acct 
aaa cache profile admin_cache 
all 
! 
aaa session-id common 
! 
! 
! 
bridge irb 
! 
! 
interface Dot11Radio0 
no ip address 
no ip route-cache 
shutdown 
speed basic-1.0 basic-2.0 basic-5.5 6.0 9.0 basic-11.0 12.0 18.0 24.0 36.0 48.0 54.0 
station-role root 
bridge-group 1 
bridge-group 1 subscriber-loop-control 
bridge-group 1 block-unknown-source 
no bridge-group 1 source-learning 
no bridge-group 1 unicast-flooding 
bridge-group 1 spanning-disabled 
! 
interface Dot11Radio1 
no ip address 
no ip route-cache 
shutdown 
speed basic-6.0 9.0 basic-12.0 18.0 basic-24.0 36.0 48.0 54.0 
station-role root 
bridge-group 1 
bridge-group 1 subscriber-loop-control 
bridge-group 1 block-unknown-source 
no bridge-group 1 source-learning 
no bridge-group 1 unicast-flooding 
bridge-group 1 spanning-disabled 
! 
interface FastEthernet0 
no ip address 
no ip route-cache 
duplex auto 
speed auto 
bridge-group 1 
no bridge-group 1 source-learning 
bridge-group 1 spanning-disabled 
! 
interface BVI1 
ip address 192.168.133.207 255.255.255.0 
no ip route-cache 
! 
ip http server 
ip http authentication aaa 
no ip http secure-server 
ip http help-path http://www.cisco.com/warp/public/779/smbiz/prodconfig/help/eag 
ip radius source-interface BVI1  
! 
tacacs-server host 192.168.133.231 key 7 105E080A16001D1908 
tacacs-server directed-request 
radius-server attribute 32 include-in-access-req format %h 
radius-server host 192.168.134.229 auth-port 1645 acct-port 1646 key 7 111918160405041E00 
radius-server vsa send accounting 
! 
control-plane 
! 
bridge 1 route ip 
! 
! 
! 
line con 0 
transport preferred all 
transport output all 
line vty 0 4 
transport preferred all 
transport input all 
transport output all 
line vty 5 15 
transport preferred all 
transport input all 
transport output all 
! 
end

Configuring the Access Point/Bridge to Provide DHCP Service

These sections describe how to configure the access point/bridge to act as a DHCP server:

•Setting up the DHCP Server

•Monitoring and Maintaining the DHCP Server Access Point

Setting up the DHCP Server

By default, access points are configured to receive IP settings from a DHCP server on your network. You can also configure an access point to act as a DHCP server to assign IP settings to devices on both your wired and wireless LANs.

When configured as an access point, the access point/bridge becomes a mini-DHCP server by default when it is configured with factory default settings and it cannot receive IP settings from a DHCP server. As a mini-DHCP server, the access point/bridge provides up to 20 IP addresses between 10.0.0.11 and 10.0.0.30 to a PC connected to its Ethernet port and to wireless client devices configured to use either no SSID or tsunami as the SSID, and with all security settings disabled. The mini-DHCP server feature is disabled automatically when you assign a static IP address to the access point/bridge.

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Note When you configure the access point/bridge as a DHCP server, it assigns IP addresses to devices on its subnet. The devices communicate with other devices on the subnet but not beyond it. If data needs to be passed beyond the subnet, you must assign a default router. The IP address of the default router should be on the same subnet as the access point configured as the DHCP server.

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For detailed information on DHCP-related commands and options, refer to the Configuring DHCP chapter in the Cisco IOS IP Configuration Guide, Release 12.3. Click this URL to browse to the "Configuring DHCP" chapter:

http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fipr_c/ipcprt1/1cfdhcp.htm

Beginning in privileged EXEC mode, follow these steps to configure an access point to provide DHCP service:

	Command	Purpose
Step 1	configure terminal	Enter global configuration mode.
Step 2	ip dhcp excluded-address low_address [ high_address ]	Exclude the access point/bridge's IP address from the range of addresses the wireless device assigns. Enter the IP address in four groups of characters, such as 10.91.6.158. the access point/bridge assumes that all IP addresses in a DHCP address pool subnet are available for assigning to DHCP clients. You must specify the IP addresses that the DHCP Server should not assign to clients. (Optional) To enter a range of excluded addresses, enter the address at the low end of the range followed by the address at the high end of the range.
Step 3	ip dhcp pool pool_name	Create a name for the pool of IP addresses that the wireless device assigns in response to DHCP requests, and enter DHCP configuration mode.
Step 4	network subnet_number [ mask | prefix-length ]	Assign the subnet number for the address pool. The access point/bridge assigns IP addresses within this subnet. (Optional) Assign a subnet mask for the address pool, or specify the number of bits that comprise the address prefix. The prefix is an alternative way of assigning the network mask. The prefix length must be preceded by a forward slash (/).
Step 5	lease { days [ hours ] [ minutes ] | infinite }	Configure the duration of the lease for IP addresses assigned by the wireless device. •days—configure the lease duration in number of days •(optional) hours—configure the lease duration in number of hours •(optional) minutes—configure the lease duration in number of minutes •infinite—set the lease duration to infinite
Step 6	default-router address [address2 ... address 8]	Specify the IP address of the default router for DHCP clients on the subnet. One IP address is required, however, you can specify up to eight addresses in one command line.
Step 7	end	Return to privileged EXEC mode.