> ## Documentation Index
> Fetch the complete documentation index at: https://coollabstechnologiesbt.mintlify.site/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# FAQ

> Here you can find answers to the most common questions, errors and problems.

## Server

<AccordionGroup>
  <Accordion title="Permission denied (publickey).">
    Error: `Server is not reachable. Reason: root@host.docker.internal: Permission denied (publickey).`

    Your Coolify instance cannot reach the server it is running on. During installation, a public key is generated to `/data/coolify/ssh/keys/id.root@host.docker.internal.pub` and automatically added to `~/.ssh/authorized_keys`.

    If it is not added, you can add it manually by running the following command on your server:

    ```bash
    cat /data/coolify/ssh/keys/id.root@host.docker.internal.pub >> ~/.ssh/authorized_keys
    ```
  </Accordion>

  <Accordion title="Custom SSH Port">
    If you would like to use a custom SSH port, you can set it in the `Server` tab of your server.

    If you are self-hosting Coolify, you can simply set it after you installed Coolify on the `localhost` server.
  </Accordion>

  <Accordion title="Increase Concurrent Builds">
    If you would like to increase the number of concurrent builds, you can set it in the `Server` tab of your server.
  </Accordion>

  <Accordion title="Coolify Cloud Public IPs">
    If you need the public facing IPs to allow inbound connections to your servers, here is an up-to-date list of IPs that you can use to whitelist:

    * [https://coolify.io/ipv4.txt](https://coolify.io/ipv4.txt)
    * [https://coolify.io/ipv6.txt](https://coolify.io/ipv6.txt)
  </Accordion>
</AccordionGroup>

## Cloudflare

<AccordionGroup>
  <Accordion title="Configured but application is not reachable.">
    You need to set your SSL/TLS configuration to at least `Full` in your Cloudflare dashboard.

    Documentation: [https://developers.cloudflare.com/ssl/origin-configuration/ssl-modes/full/](https://developers.cloudflare.com/ssl/origin-configuration/ssl-modes/full/)
  </Accordion>

  <Accordion title="Too many redirections.">
    You need to set your SSL/TLS configuration to at least `Full` in your Cloudflare dashboard.

    Documentation: [https://developers.cloudflare.com/ssl/origin-configuration/ssl-modes/full/](https://developers.cloudflare.com/ssl/origin-configuration/ssl-modes/full/)
  </Accordion>
</AccordionGroup>

## Applications

<AccordionGroup>
  <Accordion title="How to map a port the server?">
    If you want to map a port the host system (server), you need to use [Ports
    Mappings](/docs/knowledge-base/applications#port-mappings) feature.
  </Accordion>
</AccordionGroup>