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This chapter describes the commands used to establish password protection and configure privilege levels. Password protection lets you restrict access to a network or a network device. Privilege levels let you define what commands users can issue after they have logged in to a network device.
For information on how to establish password protection or configure privilege levels, refer to the "Configuring Passwords and Privileges" chapter in the Cisco IOS Security Configuration Guide. For configuration examples using the commands in this chapter, refer to the "Passwords and Privileges Configuration Examples" section located at the end of the "Configuring Passwords and Privileges" chapter in the Cisco IOS Security Configuration Guide.
To set a local password to control access to various privilege levels, use the enable password command in global configuration mode. Use the no form of this command to remove the password requirement.
enable password [level level] {password | [encryption-type] encrypted-password}
Syntax Description
level level (Optional) Level for which the password applies. You can specify up to 16 privilege levels, using numbers 0 through 15. Level 1 is normal EXEC-mode user privileges. If this argument is not specified in the command or the no form of the command, the privilege level defaults to 15 (traditional enable privileges). password Password users type to enter enable mode. encryption-type (Optional) Cisco-proprietary algorithm used to encrypt the password. Currently the only encryption type available is 7. If you specify encryption-type, the next argument you supply must be an encrypted password (a password already encrypted by a Cisco router). encrypted-password Encrypted password you enter, copied from another router configuration.
Defaults
No password is defined. The default is level 15.
Command Modes
Global configuration
Command History
10.0 This command was introduced.
Release
Modification
Usage Guidelines
Use this command with the level option to define a password for a specific privilege level. After you specify the level and the password, give the password to the users who need to access this level. Use the privilege level (global) configuration command to specify commands accessible at various levels.
You will not ordinarily enter an encryption type. Typically you enter an encryption type only if you copy and paste into this command a password that has already been encrypted by a Cisco router.
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Caution If you specify an encryption type and then enter a clear text password, you will not be able to reenter enable mode. You cannot recover a lost password that has been encrypted by any method. |
If the service password-encryption command is set, the encrypted form of the password you create with the enable password command is displayed when a more nvram:startup-config command is entered.
You can enable or disable password encryption with the service password-encryption command.
An enable password is defined as follows:
Examples
The following example enables the password pswd2 for privilege level 2:
enable password level 2 pswd2
The following example sets the encrypted password $1$i5Rkls3LoyxzS8t9, which has been copied from a router configuration file, for privilege level 2 using encryption type 7:
enable password level 2 7 $1$i5Rkls3LoyxzS8t9
Related Commands
disable Exits privileged EXEC mode and return to user EXEC mode, enter the disable EXEC command. enable Enters privileged EXEC mode. Specifies an additional layer of security over the enable password command. Sets the privilege level for a command. Encrypts passwords. Displays your current level of privilege.
Command
Description
To specify an additional layer of security over the enable password command, use the enable secret command in global configuration mode. Use the no form of this command to turn off the enable secret function.
enable secret [level level] {password | [encryption-type] encrypted-password}
Syntax Description
level level (Optional) Level for which the password applies. You can specify up to sixteen privilege levels, using numbers 0 through 15. Level 1 is normal EXEC-mode user privileges. If this argument is not specified in the command or in the no form of the command, the privilege level defaults to 15 (traditional enable privileges). The same holds true for the no form of the command. password Password for users to enter enable mode. This password should be different from the password created with the enable password command. encryption-type (Optional) Cisco-proprietary algorithm used to encrypt the password. Currently the only encryption type available for this command is 5. If you specify encryption-type, the next argument you supply must be an encrypted password (a password encrypted by a Cisco router). encrypted-password Encrypted password you enter, copied from another router configuration.
Defaults
No password is defined. The default level is 15.
Command Modes
Global configuration
Command History
11.0 This command was introduced.
Release
Modification
Usage Guidelines
Use this command to provide an additional layer of security over the enable password. The enable secret command provides better security by storing the enable secret password using a non-reversible cryptographic function. The added layer of security encryption provides is useful in environments where the password crosses the network or is stored on a TFTP server.
You will not ordinarily enter an encryption type. Typically you enter an encryption type only if you paste into this command an encrypted password that you copied from a router configuration file.
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Caution If you specify an encryption-type and then enter a clear text password, you will not be able to reenter enable mode. You cannot recover a lost password that has been encrypted by any method. |
If you use the same password for the enable password and enable secret commands, you receive an error message warning that this practice is not recommended, but the password will be accepted. By using the same password, however, you undermine the additional security the enable secret command provides.
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Note After you set a password using the enable secret command, a password set using the enable password command works only if the enable secret is disabled or an older version of Cisco IOS software is being used, such as when running an older rxboot image. Additionally, you cannot recover a lost password that has been encrypted by any method. |
If service password-encryption is set, the encrypted form of the password you create here is displayed when a more nvram:startup-config command is entered.
You can enable or disable password encryption with the service password-encryption command.
An enable password is defined as follows:
Examples
The following example specifies the enable secret password of greentree:
enable secret greentree
After specifying an enable secret password, users must enter this password to gain access. Any passwords set through enable password will no longer work.
Password: greentree
The following example enables the encrypted password $1$FaD0$Xyti5Rkls3LoyxzS8, which has been copied from a router configuration file, for privilege level 2 using encryption type 5:
enable password level 2 5 $1$FaD0$Xyti5Rkls3LoyxzS8
Related Commands
enable Enters privileged EXEC mode. Sets a local password to control access to various privilege levels.
Command
Description
To specify a password on a line, use the password command in line configuration mode. Use the no form of this command to remove the password.
password password
Syntax Description
password Character string that specifies the line password. The first character cannot be a number. The string can contain any alphanumeric characters, including spaces, up to 80 characters. You cannot specify the password in the format number-space-anything. The space after the number causes problems. For example, hello 21 is a legal password, but 21 hello is not. The password checking is case sensitive. For example, the password Secret is different than the password secret.
Defaults
No password is specified.
Command Modes
Line configuration
Command History
10.0 This command was introduced.
Release
Modification
Usage Guidelines
When an EXEC process is started on a line with password protection, the EXEC prompts for the password. If the user enters the correct password, the EXEC prints its normal privileged prompt. The user can try three times to enter a password before the EXEC exits and returns the terminal to the idle state.
Examples
The following example removes the password from virtual terminal lines 1 to 4:
line vty 1 4
no password
Related Commands
Sets a local password to control access to various privilege levels.
Command
Description
To set the privilege level for a command, use the privilege level (global) command in configuration mode. Use the no form of this command to revert to default privileges for a given command.
privilege mode [level level command | reset command]
Syntax Description
Defaults
Level 15 is the level of access permitted by the enable password.
Level 1 is normal EXEC-mode user privileges.
Command Modes
Global configuration
Command History
10.3 This command was introduced.
Release
Modification
Usage Guidelines
The password for a privilege level defined using the privilege level global configuration command is configured using the enable password command.
Level 0 can be used to specify a more-limited subset of commands for specific users or lines. For example, you can allow user "guest" to use only the show users and exit commands.
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Note There are five commands associated with privilege level 0: disable, enable, exit, help, and logout. If you configure AAA authorization for a privilege level greater than 0, these five commands will not be included. |
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.
Table 29 shows the acceptable options for the mode argument in the privilege level command
Command | Description |
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Examples
The following example sets the configure command to privilege level 14 and establish SecretPswd14 as the password users must enter to use level 14 commands:
privilege exec level 14 configure enable secret level 14 SecretPswd14 The following example resets the configure command privilege level: privilege exec reset configure
Related Commands
Sets a local password to control access to various privilege levels. Specifies an additional layer of security over the enable password command. Sets the default privilege level for a line.
Command
Description
To set the default privilege level for a line, use the privilege level (line) command in line configuration mode. Use the no form of this command to restore the default user privilege level to the line.
privilege level level
Syntax Description
level Privilege level associated with the specified line.
Defaults
Level 15 is the level of access permitted by the enable password.
Level 1 is normal EXEC-mode user privileges.
Command Modes
Line configuration
Command History
10.3 This command was introduced.
Release
Modification
Usage Guidelines
Users can override the privilege level you set using this command by logging in to the line and enabling a different privilege level. They can lower the privilege level by using the disable command. If users know the password to a higher privilege level, they can use that password to enable the higher privilege level.
You can use level 0 to specify a subset of commands for specific users or lines. For example, you can allow user "guest" to use only the show users and exit commands.
You might specify a high level of privilege for your console line to restrict line usage.
Examples
The following example configures the auxiliary line for privilege level 5. Anyone using the auxiliary line has privilege level 5 by default:
line aux 0 privilege level 5
The following example sets all show ip commands, which includes all show commands, to privilege level 7:
privilege exec level 7 show ip route
This is equivalent to the following command:
privilege exec level 7 show
The following example sets the show ip route to level 7 and the show and show ip commands to level 1:
privilege exec level 7 show ip route privilege exec level 1 show ip
Related Commands
Sets a local password to control access to various privilege levels.
Command
Description
To encrypt passwords, use the service password-encryption command in global configuration mode. Use the no form of this command to restore the default.
service password-encryptionSyntax Description
This command has no arguments or keywords.
Defaults
No encryption.
Command Modes
Global configuration
Command History
10.0 This command was introduced.
Release
Modification
Usage Guidelines
The actual encryption process occurs when the current configuration is written or when a password is configured. Password encryption is applied to all passwords, including username passwords, authentication key passwords, the privileged command password, console and virtual terminal line access passwords, and BGP neighbor passwords. This command is primarily useful for keeping unauthorized individuals from viewing your password in your configuration file.
When password encryption is enabled, the encrypted form of the passwords is displayed when a more system:running-config command is entered.
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Caution This command does not provide a high level of network security. If you use this command, you should also take additional network security measures. |
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Note You cannot recover a lost encrypted password. You must clear NVRAM and set a new password. |
Examples
The following example causes password encryption to take place:
service password-encryption
Related Commands
Sets a local password to control access to various privilege levels. key-string (authentication) Specifies the authentication string for a key. neighbor password Enables MD5 authentication on a TCP connection between two BGP peers.
Command
Description
To display your current level of privilege, use the show privilege command in EXEC mode.
show privilegeSyntax Description
This command has no arguments or keywords.
Command Modes
EXEC
Command History
10.3 This command was introduced.
Release
Modification
Usage Guidelines
Use this command to display your current level of privilege.
Examples
The following example shows sample output from the show privilege command. The current privilege level is 15.
Router# show privilege Current privilege level is 15
Related Commands
Sets a local password to control access to various privilege levels. Specifies an additional layer of security over the enable password command.
Command
Description
To establish a username-based authentication system, use the username command in global configuration mode.
username name {nopassword | password password | password encryption-type encrypted-password}
Syntax Description
name Host name, server name, user ID, or command name. The name argument can be only one word. White spaces and quotation marks are not allowed. nopassword No password is required for this user to log in. This is usually most useful in combination with the autocommand keyword. password Specifies a possibly encrypted password for this username. password Password a user enters. encryption-type (Optional) Single-digit number that defines whether the text immediately following is encrypted, and, if so, what type of encryption is used. Currently defined encryption types are 0, which means that the text immediately following is not encrypted, and 7, which means that the text is encrypted using a Cisco-defined encryption algorithm. encrypted-password (Optional) Encrypted password a user enters. password Password to access the name argument. A password must be from 1 to 25 characters, can contain embedded spaces, and must be the last option specified in the username command. secret For CHAP authentication: specifies the secret for the local router or the remote device. The secret is encrypted when it is stored on the local router. The secret can consist of any string of up to 11 ASCII characters. There is no limit to the number of username and password combinations that can be specified, allowing any number of remote devices to be authenticated. access-class (Optional) Specifies an outgoing access list that overrides the access list specified in the access-class line configuration command. It is used for the duration of the user's session. number (Optional) Access list number. autocommand (Optional) Causes the specified command to be issued automatically after the user logs in. When the command is complete, the session is terminated. Because the command can be any length and contain embedded spaces, commands using the autocommand keyword must be the last option on the line. command (Optional) The command string. Because the command can be any length and contain embedded spaces, commands using the autocommand keyword must be the last option on the line. callback-dialstring (Optional) For asynchronous callback only: permits you to specify a telephone number to pass to the DCE device. telephone-number (Optional) For asynchronous callback only: telephone number to pass to the DCE device. callback-rotary (Optional) For asynchronous callback only: permits you to specify a rotary group number. The next available line in the rotary group is selected. rotary-group-number (Optional) For asynchronous callback only: integer between 1 and 100 that identifies the group of lines on which you want to enable a specific username for callback. callback-line (Optional) For asynchronous callback only: specific line on which you enable a specific username for callback. tty (Optional) For asynchronous callback only: standard asynchronous line. line-number (Optional) For asynchronous callback only: relative number of the terminal line (or the first line in a contiguous group) on which you want to enable a specific username for callback. Numbering begins with zero. ending-line-number (Optional) Relative number of the last line in a contiguous group on which you want to enable a specific username for callback. If you omit the keyword (such as tty), then line-number and ending-line-number are absolute rather than relative line numbers. dnis Do not require password when obtained via DNIS. nocallback-verify (Optional) Authentication not required for EXEC callback on the specified line. noescape (Optional) Prevents a user from using an escape character on the host to which that user is connected. nohangup (Optional) Prevents Cisco IOS software from disconnecting the user after an automatic command (set up with the autocommand keyword) has completed. Instead, the user gets another EXEC prompt. privilege (Optional) Sets the privilege level for the user. level (Optional) Number between 0 and 15 that specifies the privilege level for the user. user-maxlinks Limit the user's number of inbound links. number User-maxlinks limit for inbound links.
Defaults
No username-based authentication system is established.
Command Modes
Global configuration
Command History
10.0 This command was introduced. 11.1 The following keywords and arguments were added:
Release
Modification
Usage Guidelines
The username command provides username and/or password authentication for login purposes only.
Multiple username commands can be used to specify options for a single user.
Add a username entry for each remote system that the local router communicates with and requires authentication from. The remote device must have a username entry for the local router. This entry must have the same password as the local router's entry for that remote device.
This command can be useful for defining usernames that get special treatment. For example, you can use this command to define an "info" username that does not require a password, but connects the user to a general purpose information service.
The username command is required as part of the configuration for the Challenge Handshake Authentication Protocol (CHAP). Add a username entry or each remote system from which the local router requires authentication.
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Note To enable the local router to respond to remote CHAP challenges, one username name entry must be the same as the hostname entry that has already been assigned to the other router. |
If there is no secret specified and the debug serial-interface command is enabled, an error is displayed when a link is established and the CHAP challenge is not implemented. CHAP debugging information is available using the debug ppp negotiation, debug serial-interface, and debug serial-packet commands. For more information about debug commands, refer to the a Cisco IOS Debug
Command Reference.
Examples
The following example implements a service similar to the UNIX who command, which can be entered at the login prompt and lists the current users of the router, the username command takes the following form:
username who nopassword nohangup autocommand show users
The following example implements an information service that does not require a password to be used, the command takes the following form:
username info nopassword noescape autocommand telnet nic.ddn.mil
The following example implements an ID that works even if the TACACS+ servers all break, the command takes the following form:
username superuser password superpassword
The following example enables CHAP on interface serial 0 of "server_l." It also defines a password for a remote server named "server_r."
hostname server_l
username server_r password their system
interface serial 0
encapsulation ppp
ppp authentication chap
When you look at your configuration file, the password will be encrypted and the display will look similar to the following:
hostname server_l
username server_r password 7 02120C5E02144F32555D1D1c08
interface serial 0
encapsulation ppp
ppp authentication chap
The username command is required as part of the configuration file for CHAP. Add a username entry for each remote system from which the local router requires authentication.
Related Commands
arap callback Enables an ARA client to request a callback from an ARA client. callback forced-wait Forces the Cisco IOS software to wait before initiating a callback to a requesting client. ppp callback (DDR) Enables a dialer interface that is not a DTR interface to function either as a callback client that requests callback or as a callback server that accepts callback requests. ppp callback (PPP client) Enables a PPP client to dial into an asynchronous interface and request a callback.
Command
Description
Posted: Wed Sep 13 15:54:27 PDT 2000
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