- **CentOS** (7.0+), **Debian** (9/Stretch+) or **Ubuntu** (16.04+) server. We only strive to support released stable versions of distributions, not betas or pre-releases. This playbook can take over your whole server or co-exist with other services that you have there.
- for ancient distributions like **CentOS 7.0**, we recommend that you do a manual systemd-journald adjustment. Because the Synapse chat server is incredibly chatty when it comes to logging (here's [one such issue](https://github.com/matrix-org/synapse/issues/4751) describing the problem), be advised that systemd's journald default logging restrictions may not be high enough to capture all log messages generated by Synapse. This is especially true if you've got a busy (Synapse) server. We advise that you manually add `RateLimitInterval=0` and `RateLimitBurst=0` under `[Storage]` in the `/etc/systemd/journald.conf` file, followed by restarting the logging service (`systemctl restart systemd-journald`).
- [Python](https://www.python.org/) being installed on the server. Most distributions install Python by default, but some don't (e.g. Ubuntu 18.04) and require manual installation (something like `apt-get install python`).
- a `cron`-like tool installed on the server such as `cron` or `anacron` to automatically schedule the Let's Encrypt SSL certificates. *This can be ignored if you use your own SSL certificates.*
- the [Ansible](http://ansible.com/) program being installed on your own computer. It's used to run this playbook and configures your server for you. Take a look at [our guide about Ansible](ansible.md) for more information, as well as [version requirements](ansible.md#supported-ansible-versions) and alternative ways to run Ansible.
- either the `dig` tool or `python-dns` installed on your own computer. Used later on, by the playbook's [services check](maintenance-checking-services.md) feature.
- an HTTPS-capable web server at the base domain name (`<your-domain>`) which is capable of serving static files. Unless you decide to [Serve the base domain from the Matrix server](configuring-playbook-base-domain-serving.md) or alternatively, to use DNS SRV records for [Server Delegation](howto-server-delegation.md).
- some TCP/UDP ports open. This playbook configures the server's internal firewall for you. In most cases, you don't need to do anything special. But **if your server is running behind another firewall**, you'd need to open these ports: `80/tcp` (HTTP webserver), `443/tcp` (HTTPS webserver), `3478/tcp` (TURN over TCP), `3478/udp` (TURN over UDP), `5349/tcp` (TURN over TCP), `5349/udp` (TURN over UDP), `8448/tcp` (Matrix Federation API HTTPS webserver), the range `49152-49172/udp` (TURN over UDP).
