Manual Chapter : Configuring Remote TACACS+ Authentication

Applies To:

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BIG-IP LTM

  • 15.0.1, 15.0.0
Manual Chapter

Configuring Remote TACACS+ Authentication

Overview of remote authentication for application traffic

As an administrator in a large computing environment, you can set up the BIG-IP® system to use this server to authenticate any network traffic passing through the BIG-IP system. This type of traffic passes through a virtual server and through Traffic Management Microkernel (TMM) interfaces. Remote authentication servers typically use one of these protocols:
  • Lightweight Directory Access Protocol (LDAP)
  • Remote Authentication Dial-in User Service (RADIUS)
  • TACACS+ (derived from Terminal Access Controller Access Control System [TACACS])
  • Online Status Certificate Protocol (OCSP)
  • Certificate Revocation List Distribution Point (CRLDP)
To configure remote authentication for this type of traffic, you must create a configuration object and a profile that correspond to the type of authentication server you are using to store your user accounts. For example, if your remote authentication server is an LDAP server, you create an LDAP configuration object and an LDAP profile. When implementing a RADIUS, SSL OCSP, or CRLDP authentication module, you must also create a third type of object. For RADIUS and CRLDP authentication, this object is referred to as a server object. For SSL OCSP authentication, this object is referred to as an OCSP responder.

Task summary for configuring remote TACACS authentication

To configure remote authentication for this type of traffic, you must create a configuration object and a profile that correspond to the type of authentication server you are using to store your user accounts.

Creating a TACACS+ configuration object

A
TACACS+ configuration object
specifies information that the BIG-IP system needs to perform the remote authentication. For example, the configuration object specifies the IP address of the remote TACACS+ server.
  1. On the Main tab of the navigation pane, click
    Local Traffic
    Profiles
    .
  2. From the Authentication menu, choose
    Configurations
    .
  3. Click
    Create
    .
  4. In the
    Name
    field, type a unique name for the configuration object, such as
    my_tacacs_config
    .
  5. From the
    Type
    list, select
    TACACS+
    .
  6. For the
    Servers
    setting, select a server name in the
    Available
    list, and using the Move button, move the name to the
    Selected
    list.
  7. In the
    Secret
    field, type the secret key used to encrypt and decrypt packets sent or received from the server.
    Do not use the pound sign ( # ) in the secret for TACACS+ servers.
  8. In the
    Confirm Secret
    field, re-type the secret you specified in the
    Secret
    field.
  9. From the
    Encryption
    list, select an encryption option:
    Enabled
    Choose this option if you want the system to encrypt the TACACS+ packets.
    Disabled
    Choose this option if you want the system to send unencrypted TACACS+ packets.
  10. In the
    Service Name
    field, type the name of the service that the user is requesting to be authenticated for use; typically,
    ppp
    .
    Specifying the service makes it possible for the TACACS+ server to behave differently for different types of authentication requests. Examples of service names that you can specify are:
    ppp
    ,
    slip
    ,
    arap
    ,
    shell,
    tty-daemon
    ,
    connection
    ,
    system
    , and
    firewall
    .
  11. In the
    Protocol Name
    field, type the name of the protocol associated with the value specified in the
    Service Name
    field.
    This value is usually
    ip
    . Examples of protocol names that you can specify are:
    ip
    ,
    lcp
    ,
    ipx
    ,
    stalk
    ,
    vines
    ,
    lat
    ,
    xremote
    ,
    tn3270
    ,
    telnet
    ,
    rlogin
    ,
    pad
    ,
    vpdn
    ,
    ftp
    ,
    http
    ,
    deccp
    ,
    osicp
    , and
    unknown
    .
  12. Click
    Finished
    .
You now have a configuration object that a TACACS+ authentication profile can reference.

Creating a custom TACACS+ profile

The next task in configuring TACACS+-based remote authentication on the BIG-IP system is to create a custom TACACS+ profile.
  1. On the Main tab, click
    Local Traffic
    Profiles
    Authentication
    Profiles
    .
    The Profiles list screen opens.
  2. Click
    Create
    .
    The New Authentication Profile screen opens.
  3. In the
    Name
    field, type a unique name for the profile.
  4. Select
    TACACS+
    from the
    Type
    list.
  5. Select
    tacacs
    in the
    Parent Profile
    list.
  6. Select the TACACS+ configuration object that you created from the
    Configuration
    list.
  7. Click
    Finished
    .
The custom TACACS+ profile appears in the
Profiles
list.

Modifying a virtual server for TACACS+ authentication

The final task in the process of implementing authentication using a remote TACACS+ server is to assign the custom TACACS+ profile and an existing default authentication iRule to a virtual server that is configured to process HTTP traffic (that is, a virtual server to which an HTTP profile is assigned).
  1. On the Main tab, click
    Local Traffic
    Virtual Servers
    .
    The Virtual Server List screen opens.
  2. Click the name of a virtual server.
  3. From the
    Configuration
    list, select
    Advanced
    .
  4. For the
    Authentication Profiles
    setting, in the
    Available
    field, select a custom TACACS+ profile, and using the
    Move
    button, move the custom TACACS+ profile to the
    Selected
    field.
  5. Click
    Update
    to save the changes.
The virtual server is assigned the custom TACACS+ profile.