macOS 14 and later or Windows 10 version 2024 and later desktop
devices
Contact your Palo Alto Networks account representative to
activate the Prisma Access Agent feature
Prisma Access Agent captive portal support is designed to improve the connectivity
experience for mobile users who frequently connect from networks with captive
portals, such as hotels, cafes, and airports. This feature uses the Prisma Access
Agent embedded browser to automatically detect and handle captive portal
authentication, ensuring integrated and secure access to corporate resources.
The captive portal detection mechanism uses a set of predefined URLs and network
probes to identify the presence of a captive portal. This detection process is
reliable and addresses issues where some captive portal providers could bypass
traditional detection techniques.
With captive portal detection, internet access becomes available only after users log
in to the captive portal. When a user connects to the Wi-Fi network and Prisma
Access Agent detects a captive portal, the agent launches the embedded browser to
handle the authentication process, containing the interaction within a controlled
environment and mitigating security risks associated with external browser use.
When a user logs in successfully and the internet becomes reachable, the Prisma
Access Agent automatically establishes a connection. If the user fails to log in to
the captive portal, the agent blocks all traffic.
By default, Prisma Access Agent uses the embedded browser for SAML authentication and
captive portal.
User Experience in a Captive Portal Environment
When a user connects to a network with a captive portal, such as in a hotel or
airport, the Prisma Access Agent automatically detects the captive portal. The
embedded browser within the Prisma Access Agent
then
opens, displaying the captive portal login page. The user can enter their
credentials and accept the terms of service as required by the network provider.
The following is an example of a captive portal login page in the embedded
browser:
Once the user successfully authenticates through the captive portal, the Prisma
Access Agent automatically establishes a secure connection to the corporate network
if the agent is configured with an always-on connection. If they are using an
on-demand connection, they can select a location to connect to the corporate
network.
If the user disconnects from the Wi-Fi network that they use
to connect to Prisma Access Agent, they will have no connection to the internet.
After they authenticate to the captive portal in the embedded browser, they will
have a connection to their corporate network.
If the captive portal authentication fails or times out, the user can retry the
process by clicking the Connect button in the agent app.
This streamlined experience ensures that users can quickly and securely connect to
networks with captive portals, maintaining productivity while traveling or working
remotely.
Verify the Presence of a Captive Portal
You can verify whether the agent detects a captive portal by using the Prisma
Access command-line tool (PACli) or checking the agent logs.
To verify the presence of the captive portal using the PACli tool:
Run the pacli captive_portal status command
on the endpoint. If Prisma Access Agent detects a captive portal, it
will return the Captive portal detected
message along with the URL of the captive portal login page. For
example:
After the user authenticates to the captive portal, the captive
portal should no longer be active. Run the pacli
captive_portal status command again. The command
output should be Captive portal not
detected. For example:
To check for captive portal-related activities in log files, check the
agent logs as follows:
Check the captive portal detection events, such as unexpected errors
and responses, in EndpointTroubleshooting (Prisma Access Agent) page in Strata Logging Service.
The agent
also writes these events to the PAS.log file on the
endpoint.
On Windows: %ProgramData%\Palo Alto
Networks\Prisma Access
Agent\Logs\PAS.log
On macOS:
~/Library/Logs/PaloAltoNetworks/Prisma Access
Agent/PAS.log
Check the captive portal detection and release events in the EndpointManagement logs in Strata Logging Service.