It seems like your browser didn't download the required fonts. Please revise your security settings and try again.
Barracuda CloudGen Firewall

This Firmware Version Is End-Of-Support

Documentation for this product is no longer updated. Please see for further information on our EoS policy.

How to Configure MSAD Authentication

  • Last updated on

Microsoft Active Directory (MSAD) is a directory service that allows authentication and authorization of network users. On the Barracuda NG Firewall you can configure MSAD as an external authentication scheme. MSAD is included with all Windows Server operating systems since Windows 2000 Server. For MSAD authentication, you can also configure the Barracuda DC Agent, which allows transparent authentication monitoring with the Barracuda NG Firewall and Microsoft® domain controllers.

  In this article:

Before you Begin

If MSAD is running in native mode on a Windows 2003 Server domain, you must deactivate Kerberos pre-authentication for each user.

To use services such FTP, URL Filter, VPN, or Firewall Authentication and Guest Access, you might need to gather group information. The distinguished name (DN) containing the group information is needed for external authentication using MSAD and LDAP (see also How to Configure LDAP Authentication). To gather group information from MSAD:

  1. Go to My Network Places > Search Active Directory
  2. Select the searching domain. 
  3. Enter the name of the user you are searching for and click Find Now
  4. After you have found the user, add the X500 Distinguished Name column.
    • Select View > Choose columns.
    • Select X500 Distinguished Name.
    • Click Add.

The DN is displayed in the search results.

Configure MSAD Authentication

  1. Open the  Authentication Service page ( Config >  Full Config  Box  > Infrastructure Services ).
  2. In the left navigation pane, select MSAD Authentication .
  3. Click  Lock .
  4. Enable MS Active Directory as external directory service.
  5. In the Basic table, add an entry for the domain controller. 
  6. Enter the name and IP address of the primary domain controller, without the domain suffix. The name must be DNS-resolvable. The IP address is optional. If given, the IP address is used instead of the hostname.
  7. In the Active directory searching user / password fields, enter the Distinguished Name (DN) and password of a user with permission to search the Active Directory and to view group information. For example: CN=search,OU=development,DC=domain,DC=local
  8. In the Base DN field, specify where to search for user information. Define the Base DN as specific as possible in order to increase the speed of the lookup and avoid timeouts.

    If you enter the domain in this field (e.g.: DC=xyz,DC=com ), Active Directory may refuse the BaseDN lookup. If possible, add an OU= entry to your BaseDN.

  9. When using NTLM authentication, enable Use MSAD-groups with NTLM to periodically synchronize user groups from MSAD and let the Barracuda NG Firewall handle them offline .
  10. When using MSAD-groups with NTLM, enable Cache MSAD-groups to reduce network traffic and load on the MSAD server.

  11. To search additional LDAP attributes for mail addresses, enter a comma separated list of LDAP attributes in the Additional Mail Fields.

    Specify a comma-separated list of meta-directory field names that should also be searched for a mail address. Only LDAP attributes are allowed, no spaces and no GUI description fields. If you are not sure, use an LDAP browser. All additional fields are searched via a pattern search (prepended * and appended *).

  12. Select Use SSL  when establishing the connection to the LDAP directory using SSL.
  13. Select Follow referrals  to search the MSAD global catalog and follow LDAP referrals.
  14. Click OK.
  15. If group information is queried from a different authentication scheme, select the scheme from the User Info Helper Scheme list.
  16. In the Group Filter Patterns table, you can add patterns to filter group information from the directory service.

    • Group Filter Pattern: *SSL*
    • User01: CN=foo, OU=bar, DC=foo-bar, DC=foo
    • User02: CN=SSL VPN, DC=foo-bar, DC=foo

    In this example, User01 does not have the  *SSL* pattern in its group membership string and will not match in group-based limitations.

  17. Click OK.
  18. Click Send Changes and Activate.

MSAD Authentication through the Remote Management Tunnel

To allow remote NG Firewalls to connect to the authentication server through the remote management tunnel, you must activate the outbound BOX-AUTH-MGMT-NAT host firewall rule. Per default this rule is disabled.

Last updated on