+### 2.3. Configure `syncthing`
+
+Some initial tasks should be performed with a new `syncthing` instance
+in order to configure it to work with other `syncthing` instances.
+
+a. Connect to the Syncthing **WebUI**
+b. Determine the instance's **Device ID**.
+c. Add a **remote device**.
+d. Create a **shared folder**.
+
+#### 2.3.a. Connect to the **WebUI**
+
+Syncthing may be configured via a "WebUI", which is a configuration
+page accessible by a web browser such as Firefox. The address that
+must be entered into a web browser's address bar may be:
+
+ http://localhost:8384
+ http://127.0.0.1:8384
+
+If the `syncthing` instance is running on a headless machine
+accessible only via `ssh`, then the WebUI may be accessed by setting
+up an "SSH tunnel". One end of the tunnel will be the headless machine
+and the other end will be a machine equipped with a keyboard, monitor,
+and a web browser. In order to establish an `ssh` tunnel with a remote
+headless machine's `syncthing` isntance, run one of the following
+commands (both are equivalent).
+
+ $ ssh -L 9999:localhost:8384 username@yourserver
+ $ ssh -L 127.0.0.1:9999:127.0.0.1:8384 username@yourserver
+
+Then, open your web browser and enter `http://localhost:9999` into the
+address bar. This will cause the WebUI of the `syncthing` instance
+running on the remote machine `yourserver` to appear.
+
+NOTE: The details of setting up machines to connect via `ssh` are not
+described here.
+
+#### 2.3.b. Determine the **Device ID**
+
+Upon setting up a new `syncthing` instance on a new device, a unique
+identifier is generated (derived from the hash of the instance's
+public key). This identifier is called a "**Device ID**". This ID is
+what one `syncthing` instance uses to connect to another. The ID may
+be found by selecting the "Actions" menu at the top right of the WebUI
+webpage and selecting "Show ID" from the dropdown menu. A 64-character
+string of numbers and capitalized letters will appear as well as a QR
+code encoding this same string.
+
+#### 2.3.c. Add a **remote device**
+
+Once you have a `syncthing` instance's Device ID, then you can enter
+it into another instance in order to establish a connection between
+the two instances through which files in shared folders may be
+synchronized.
+
+A "Remote Device" (a remote `syncthing` instance) may be added via the
+WebUI by clicking on the "Add Remote Device" button and entering the
+Device ID in the "General" tab. Shared folders may be specified in the
+"Sharing" tab. The Device IDs of `syncthing` instances already
+detected on the local network may already be populated in the General
+tab but if you care about the security of your data you should
+double-check that the Device ID matches before clicking "Save".
+
+#### 2.3.d. Create a **shared folder**.
+
+The "Shared Folder" fulfills the primary function of `syncthing`:
+synchronizing file changes of specified directories between different
+machines across the internet.
+
+You may create a "Shared Folder" by clicking the "Add Folder"
+button. A window called "Add Folder" should appear with four tabs:
+"General", "Sharing", "File Versioning", and "Ignore Patterns".
+
+The following fields of the "General" tab should be populated as
+follows:
+
+* **Folder Label**: A label that appears in the WebUI. I would suggest
+ something like `username_PURPOSE` since this label is suggested to
+ Remote Devices when a folder is first shared.
+
+* **Folder ID**: A unique alphanumeric string that is automatically
+ generated by `syncthing`. You shouldn't have to change this.
+
+* **Folder Path**: The path within the file system of the machine in
+ which `syncthing` is running. For GNU/Linux Debian machines, I would
+ suggest something like: `~/Sync/username_PURPOSE` which should
+ auto-expand into `/home/username/Sync/username_PURPOSE`.
+
+You may also specify with which Remote Devices to share this new
+Shared Folder by clicking on the "Sharing" tab.
+
+In the "File Versioning" tab, you may specify rules for keeping local
+versions of files in this sparticular Shared Folder. By default, no
+versions are kept.
+
+In the "Ignore Patterns" tab, you may specify rules for ignoring files
+based upon their file names. By default, no ignore patterns are
+specified.
+