.. title:: Troubleshooting

Troubleshooting
===============

Connection to Session Hangs - Requesting Kasm
---------------------------------------------

When creating a new session, the
Administrators can limit access to websites by defining **Web Filter Policies**.

.. note::
    When troubleshooting this issue, always test by creating new sessions after making changes.
    Resuming a session may not have the changes applied.


.. figure:: /images/troubleshooting/requesting_kasm/requesting_kasm.png
    :width: 60%
    :align: center

    Session hangs at requesting Kasm



Client-side issues
^^^^^^^^^^^^^^^^^^

.. tip::
    If the Kasm Server deployment is internet accessible, consider testing access via a browser using the Kasm Live Demo
    to help rule out client-side issues. You can sign up for the free demo at https://kasmweb.com


* **Disable Browser Extensions**

    Some browser extensions have been know to cause conflicts when making connections to Kasm Sessions. Disable any
    any browser extensions/add-ons that may be enabled. Avoid using "incognito" or "private-browsing" modes while
    troubleshooting.

* **Corporate Proxies - WebSockets**

    Some corporate proxies/firewalls and other security appliances may not support proxying WebSockets, which is needed
    to establish a connection to Kasm sessions. You can verify your environment supports WebSockets by visiting:
    https://www.websocket.org/echo.html .

    You may see the UI cycle between "Requesting Kasm..." and "Connecting..." repeatedly. The following errors will
    repeat in the Console tab of the Develop Tools for the browser.

    .. figure:: /images/troubleshooting/requesting_kasm/websocket_error.png
        :width: 80%
        :align: center

        Session hangs at requesting Kasm



Server-side issues
^^^^^^^^^^^^^^^^^^

* **Compatible Docker Version**

    Ensure the system is running compatible versions of :code:`docker` and :code:`docker-compose`. See
    :doc:`System Requirements <../install/system_requirements>` for more details.



* **Reverse Proxy Issues**

    If running Kasm behind a reverse proxy such as NGINX, please consult the :doc:`Reverse Proxy Guide <../how_to/reverse_proxy>`
    The reverse proxy used, must support WebSockets, and the Zone configuration must also be updated accordingly.


* **Name Resolution and General Connectivity**

    If accessing Kasm Server via DNS name, ensure the Kasm Server services can properly resolve the same address.
    The Kasm services must also be able to connect to user-facing address. During installation, docker will create
    several local sub interfaces and Kasm services are assigned addresses on those bridged networks. Ensure firewalls
    or security groups are not blocking access.

    Conduct the following tests from the Kasm Server to ensure name resolution and general connectivity are
    working properly. If these items fail, correct the dns/networking/firewall issues.

    .. code-block:: bash

        # Test using the URL used to connect to the Kasm UI
        sudo docker exec -it kasm_proxy wget https://<your.kasm.server>:443

        # Test using the IP of the Kasm Server if your deployment is using a reverse proxy. If Kasm Server was installed using a non-standard port. Specify that port here
        sudo docker exec -it kasm_proxy wget https://<your.kasm.server.ip>:443