FortiOS can provide single sign-on capabilities to Windows AD, Citrix, VMware Horizon, Novell eDirectory, and Microsoft Exchange users with the help of agent software installed on these networks. The agent software sends information about user logons to the FortiGate unit. With user information such as IP address and user group memberships from the network, FortiGate security policies can allow authenticated network access to users who belong to the appropriate user groups without requesting their credentials again.
Fortinet Single Sign-On (FSSO), through agents installed on the network, monitors user logons and passes that information to the FortiGate unit. When a user logs on at a workstation in a monitored domain, FSSO:
Detects the logon event and records the workstation name, domain, and user,
Resolves the workstation name to an IP address,
Determines which user groups the user belongs to,
Sends the user logon information, including IP address and groups list, to the FortiGate unit, and
Creates one or more log entries on the FortiGate unit for this logon event as appropriate.
When the user tries to access network resources, the FortiGate unit selects the appropriate security policy for the destination. If the user belongs to one of the permitted user groups associated with that policy then the connection is allowed, otherwise the connection is denied.
Several different FSSO agents can be used in an FSSO implementation:
Domain Controller (DC) agent
Citrix/Terminal Server (TS) agent
Consult the latest FortiOS Release Notes for operating system compatibility information.
The Domain Controller (DC) agent must be installed on every domain controller when you use DC Agent mode. The DC agents monitor user logon events and pass the information to the Collector agent, which stores the information and sends it to the FortiGate unit.
The eDirectory agent is installed on a Novell network to monitor user logons and send the required information to the FortiGate unit. It functions much like the Collector agent on a Windows AD domain controller. The agent can obtain information from the Novell eDirectory using either the Novell API or LDAP.
The Terminal Server (TS) agent can be installed on a Citrix, VMware Horizon 7.4, or Windows Terminal Server to monitor user logons in real time. It functions much like the DC Agent on a Windows AD domain controller.
The Collector Agent (CA) is installed as a service on a server in the Windows AD network to monitor user logons and send the required information to the FortiGate unit. The Collector agent can collect information from a DC agent (Windows AD) and TS agent (Citrix or VMware Horizon Terminal Server).
In a Windows AD network, the Collector agent can optionally obtain logon information by polling the AD domain controllers. In this case, DC agents are not needed.
The CA is responsible for DNS lookups, group verification, workstation checks, and updating FortiGates on logon records. The FSSO CA sends Domain Local Security Group and Global Security Group information to FortiGate units. The CA communicates with the FortiGate over TCP port 8000 and it listens on UDP port 8002 for updates from the DC agents.
The FortiGate device can have up to five CAs configured for redundancy. If the first CA on the list is unreachable, the next is attempted, and so on down the list until one is contacted.
All DC agents must point to the correct CA port number and IP address on domains with multiple DCs.
A FortiAuthenticator device can act much like a CA, collecting Windows AD user logon information and sending it to the FortiGate device. It is particularly useful in large installations with several FortiGate units. For more information, see the FortiAuthenticator Administration Guide.
For Windows AD networks, FortiGate devices can also provide SSO capability by directly polling Windows Security Event log entries on Windows DC for user log in information. This configuration does not require a CA or DC agent.
To configure FSSO on a FortiGate, go to Security Fabric > External Connectors.
When creating a new connector, several options for connectors are available under Endpoint/Identity:
For most FSSO Agent-based deployments, this connector option will be used. Specify either Collector Agent or Local as User Group Source to collect user groups from the Collector Agent, or to match users to user groups from a LDAP server.
This connection option directly polls Windows Security Event log entries on Windows DC for user log in information.
FortiGate can authenticate users who have authenticated on a remote RADIUS server by monitoring the RADIUS accounting records forwarded by the RADIUS server to the FortiGate.
FortiGate collects information about authenticated users from corporate Microsoft Exchange Servers.
This connector uses client IP information from Symantec Endpoint Protection Manager (SEPM) to assign dynamic IP addresses on FortiOS.
Since FSSO is commonly associated with Agent-based FSSO and Agentless FSSO, this chapter will primarily focus on the first two Security Fabric External Connector options.