This topic discusses common terminology for user identity and user control.

User awareness

Identifying users on your network using identity sources (such as or TS Agent). User awareness enables you to identify users from both authoritative (such as Active Directory) and non-authoritative (application-based) sources. To use Active Directory as an identity source, you must configure a realm and directory. For more information, see About User Identity Sources.

User control

Configuring an identity policy that you associate with an access control policy. (The identity policy is then referred to as an access control subpolicy.) The identity policy specifies the identity source and, optionally, users and groups belonging to that source.

By associating the identity policy with an access control policy, you determine whether to monitor, trust, block, or allow users or user activity in traffic on your network. For more information, see Access Control Policies.

Authoritative identity sources

A trusted server validated the user login (for example, Active Directory). You can use the data obtained from authoritative logins to perform user awareness and user control. Authoritative user logins are obtained from passive and active authentications:

• Passive authentications occur when a user authenticates through an external repository. ISE/ISE-PIC, the TS Agent, and Microsoft Active Directory are passive authentication user repositories supported by the system.

• Active authentications occur when a user authenticates through preconfigured managed devices. Captive portal is another name for active authentication. Remote Access VPN is another authentication method supported by the system. Active authentication generally uses the same user repositories as passive authentication (the exceptions being ISE/ISE-PIC, and TS Agent, which are passive only).

Non-authoritative identity sources

An unknown or untrusted server validated the user login. Traffic-based detection is the only non-authoritative identity source supported by the system. You can use the data obtained from non-authoritative logins to perform user awareness.

The following table provides a brief overview of the user identity sources supported by the system. Each identity source provides a store of users for user awareness. These users can then be controlled with identity and access control policies.

Consider the following when selecting identity sources to deploy:

• You must use traffic-based detection for non-LDAP user logins.

• You must use traffic-based detection or captive portal to record failed login or authentication activity. A failed login or authentication attempt does not add a new user to the list of users in the database.

• The captive portal identity source requires a managed device with a routed interface. You cannot use an inline (also referred to as tap mode) interface with captive portal.

Data from those identity sources is stored in the FMC's users database and the user activity database. You can configure FMC-server user downloads to automatically and regularly download new user data to your databases.

After you configure identity rules using the desired identity source, you must associate each rule with an access control policy and deploy the policy to managed devices for the policy to have any effect. For more information about access control policies and deployment, see Associating Other Policies with Access Control.

For general information about user identity, see About User Identity.

When the system detects user data from a user login, from any identity source, the user from the login is checked against the list of users in the FMC user database. If the login user matches an existing user, the data from the login is assigned to the user. Logins that do not match existing users cause a new user to be created, unless the login is in SMTP traffic. Non-matching logins in SMTP traffic are discarded.

The group to which the user belongs is associated with the user as soon as the user is seen by the FMC.

The following diagram illustrates how the system collects and stores user data:

The user activity database on the Firepower Management Center contains records of user activity on your network detected or reported by all of your configured identity sources. The system logs events in the following circumstances:

• When it detects individual logins or logoffs.

• When it detects a new user.

• When a system administrator manually delete a user.

• When the system detects a user that is not in the database, but cannot add the user because you have reached your user limit.

• When you resolve an indication of compromise associated with a user, or enable or disable indication of compromise rules for a user.

Note	If the TS Agent monitors the same users as another passive authentication identity source (such as the ISE/ISE-PIC), the FMC prioritizes the TS Agent data. If the TS Agent and another passive source report identical activity from the same IP address, only the TS Agent data is logged to the FMC.

You can view user activity detected by the system using the Firepower Management Center. (Analysis > Users > User Activity.)

The users database on the Firepower Management Center contains a record for each user detected or reported by all of your configured identity sources. You can use data obtained from an authoritative source for user control.

See About User Identity Sources for more information about the supported non-authoritative and authoritative identity sources.

The total number of users the Firepower Management Center can store depends on the Firepower Management Center model, as described in User Limits for Microsoft Active Directory. After the user limit is reached, the system prioritizes previously-undetected user data based on its identity source, as follows:

• If the new user is from a non-authoritative identity source, the system does not add the user to the database. To allow new users to be added, you must delete users manually or with a database purge.

• If the new user is from an authoritative identity source, the system deletes the non-authoritative user who has remained inactive for the longest period and adds the new user to the database.

If an identity source is configured to exclude specific user names, user activity data for those user names are not reported to the Firepower Management Center. These excluded user names remain in the database, but are not associated with IP addresses. For more information about the type of data stored by the system, see User Data in the Firepower Management Center Administration Guide.

If you have FMC high availability configured and the primary fails, no logins reported by a captive portal, ISE/ISE-PIC, TS Agent, or Remote Access VPN device can be identified during failover downtime, even if the users were previously seen and downloaded to the FMC. The unidentified users are logged as Unknown users on the FMC. After the downtime, the Unknown users are reidentified and processed according to the rules in your identity policy.

Note	If the TS Agent monitors the same users as another passive authentication identity source (ISE/ISE-PIC), the FMC prioritizes the TS Agent data. If the TS Agent and another passive source report identical activity from the same IP address, only the TS Agent data is logged to the FMC.

When the system detects a new user session, the user session data remains in the users database until one of the following occurs:

• A user on the FMC manually deletes the user session.

• An identity source reports the logoff of that user session.

• A realm ends the user session as specified by the realm's User Session Timeout: Authenticated Users, User Session Timeout: Failed Authentication Users, or User Session Timeout: Guest Users setting.

The system adds a host to the network map when it detects activity associated with an IP address in your monitored network (as defined in your network discovery policy). The number of hosts a Firepower Management Center can monitor, and therefore store in the network map, depends on its model.

You cannot view contextual data for hosts not in the network map. However, you can perform access control. For example, you can perform application control on traffic to and from a host not in the network map, even though you cannot use a compliance allow list to monitor the host's network compliance.

Note	The system counts MAC-only hosts separately from hosts identified by both IP addresses and MAC addresses. All IP addresses associated with a host are counted together as one host.