---
myst:
  html_meta:
    "description lang=en": "Changing the default listening port for Kasm Workspaces. "
    "keywords": "Kasm, How to, How-to, Listening, Port, Change"
    "property=og:locale": "en_US"
---
```{title} Listening Port
```

# Listening Port

By default the Kasm Web Application will run on port `443`. Administrators may which to change this for various reasons.

```{note}
If Kasm will be deployed behind an reverse proxy, please consult the {doc}`Reverse Proxy Guide <reverse_proxy>` for
additional configurations steps.
```

## Change Port During Installation

If you would like to run the Web Application on a different port pass the `-L` flag when calling the installer.

```Bash
sudo bash kasm_release/install.sh -L 8443
```

## Change Port Post Installation

In this example we will update the **Single Server** deployment to utilize port `8443`.

```{warning}
Changing the port of an existing installation will make existing sessions inaccessible. Administrators should
destroy all existing sessions prior to making this change.
```

- Stop All Kasm services.

  ```bash
  sudo /opt/kasm/current/bin/stop
  ```

- Update the `agent.app.config.yaml` with the desired port.

  ```bash
  sudo sed -i "s/public_port.*/public_port: 8443/g" /opt/kasm/current/conf/app/agent/agent.app.config.yaml
  ```

  - (Optional) Verify the changes with the following command.

    ```bash
    sudo grep public_port /opt/kasm/current/conf/app/agent/agent.app.config.yaml
      public_port: 8443
      public_port: 8443
    ```

- Update the Kasm Nginx proxy configuration to listen on the desired port.

  ```bash
  sudo sed -i "s/listen.*/listen 8443 ssl ;/g" /opt/kasm/current/conf/nginx/orchestrator.conf
  ```

  - (Optional) Verify the changes with the following command.

    ```bash
    sudo grep listen /opt/kasm/current/conf/nginx/orchestrator.conf
      listen 8443 ssl ;
    ```

- Update the `docker-compose.yaml` to export the desired port for `kasm_proxy` container.

  ```bash
  sudo sed -i "s/- \"443:443\"/- \"8443:8443\"/g"  /opt/kasm/current/docker/docker-compose.yaml
  ```

  - (Optional) Verify the changes with the following command.

    ```{eval-rst}
    .. parsed-literal::

      sudo grep kasm_proxy -A5 /opt/kasm/current/docker/docker-compose.yaml
        container_name: kasm_proxy
        image: "kasmweb/nginx:latest"
        ports:
          - "8443:8443"
        networks:
          - kasm_default_network

    ```

- Remove the `kasm_proxy` container so it can be recreated using the updated port mapping.

  ```bash
  sudo docker rm -f kasm_proxy
  ```

- Start All Kasm services.

  ```bash
  sudo /opt/kasm/current/bin/start
  ```

- Log into the Kasm UI. Create a new Kasm Session to verify configurations.

- If you are unable to connect to the Kasm session it's possible you may need to change the **Proxy Port** in the Zone settings

  - The default **Proxy Port** setting of 0 will usually be appropriate (Kasm Workspaces will attempt to automatically determine the correct port from window.location.port) but if you are having issues connecting, or if the port is not already set to 0 you will have to change the **Proxy Port** setting.

  - Log into the Kasm UI as an administrator.

    1. Log into the Kasm UI as an administrator.
    2. Select **Infrastructure** -> **Zones**.
    3. Select **Edit** next to each Zone.

    5) Change the **Proxy Port** setting to the desired value. (e.g `8443`)
    6) Click Save.

    ```{figure} /images/zones/proxy_port_change.webp
    :align: center
    **Proxy Port Zone Configuration**
    ```