Add note about socket-based SSH in "Securing the SSH service"

tutorials/securing-ssh/01.de.md

@@ -25,6 +25,61 @@ Dabei werden die folgenden Punkte genauer erläutert:
 
 **Voraussetzungen**
 + SSH Dienst basierend auf OpenSSH
++ Traditionelles SSH
+
+Dieses Tutorial erklärt, wie man die Datei `/etc/ssh/sshd_config` bearbeitet, die vom traditionellen SSH verwendet wird.
+
+Wenn Ihr System Socket-basiertes SSH verwendet (Ubuntu 22.10 und höher) und Sie trotzdem diesem Tutorial folgen möchten, müssen Sie `ssh.socket` deaktivieren und `ssh.service` manuel aktivieren.
+
+<blockquote>
+<details>
+<summary>Hier klicken für Beispiel-Befehle, um <kbd>ssh.socket</kbd> zu deaktivieren und <kbd>ssh.service</kbd> zu aktivieren</summary>
+
+```bash
+sudo systemctl stop ssh.socket
+sudo systemctl disable ssh.socket
+
+sudo systemctl start ssh.service
+sudo systemctl enable ssh.service
+
+sudo systemctl restart ssh
+```
+
+</details>
+</blockquote>
+
+### Prüfen ob traditionelles SSH oder Socket-basiertes SSH verwendet wird
+
+Führen Sie folgenden Befehl aus und prüfen Sie den Output:
+
+```bash
+sudo systemctl status ssh
+```
+
+* **Traditional SSH**
+
+  Der SSH Service (`ssh.service`) wird automatisch beim Systemboot von systemd gestartet.
+  ```shellsession
+  holu@example-server:~# sudo systemctl status ssh
+  ● ssh.service - OpenBSD Secure Shell server
+       Loaded: loaded (/usr/lib/systemd/system/ssh.service; enabled; preset: enabled)
+       Active: active (running)
+  ```
+  In `Loaded:` steht "enabled". 
+
+<br>
+
+* **Socket-Based SSH**
+
+  Der SSH Service (`ssh.service`) wird von `ssh.socket` erst gestartet, wenn die erste Verbindungsanfrage reinkommt.
+  ```shellsession
+  holu@example-server:~# sudo systemctl status ssh
+  ● ssh.service - OpenBSD Secure Shell server
+       Loaded: loaded (/usr/lib/systemd/system/ssh.service; disabled; preset: enabled)
+       Active: active (running)
+  TriggeredBy: ● ssh.socket
+  ```
+  In `Loaded:` steht "disabled" und der Output enthält die zusätzliche Zeile `TriggeredBy: ssh.socket`. 
 
 ## Schritt 1 - Absicherung des SSH Dienstes
 

tutorials/securing-ssh/01.en.md

@@ -25,6 +25,61 @@ The following points are explained in more detail:
 
 **Prerequisites**
 + SSH service based on OpenSSH
++ Traditional SSH
+
+This tutorial explains how to edit `/etc/ssh/sshd_config`, which is used by traditional SSH.
+
+If your system uses socket-based SSH (Ubuntu 22.10 and higher) and you still want to follow this tutorial, you will need to disable `ssh.socket` and manually enable `ssh.service`.
+
+<blockquote>
+<details>
+<summary>Click here for commands to disable <kbd>ssh.socket</kbd> and enable <kbd>ssh.service</kbd></summary>
+
+```bash
+sudo systemctl stop ssh.socket
+sudo systemctl disable ssh.socket
+
+sudo systemctl start ssh.service
+sudo systemctl enable ssh.service
+
+sudo systemctl restart ssh
+```
+
+</details>
+</blockquote>
+
+### Check if your system uses traditional SSH or socket-based SSH
+
+Run the following command and check the output:
+
+```bash
+sudo systemctl status ssh
+```
+
+* **Traditional SSH**
+
+  The SSH service (`ssh.service`) is automatically started during system boot by systemd.
+  ```shellsession
+  holu@example-server:~# sudo systemctl status ssh
+  ● ssh.service - OpenBSD Secure Shell server
+       Loaded: loaded (/usr/lib/systemd/system/ssh.service; enabled; preset: enabled)
+       Active: active (running)
+  ```
+  In `Loaded:`, it will say "enabled". 
+
+<br>
+
+* **Socket-Based SSH**
+
+  The SSH service (`ssh.service`) is started by `ssh.socket` when the first connection request comes in.
+  ```shellsession
+  holu@example-server:~# sudo systemctl status ssh
+  ● ssh.service - OpenBSD Secure Shell server
+       Loaded: loaded (/usr/lib/systemd/system/ssh.service; disabled; preset: enabled)
+       Active: active (running)
+  TriggeredBy: ● ssh.socket
+  ```
+  In `Loaded:`, it will say "disabled", and the output will also include the line triggered by `ssh.socket`. 
 
 ## Step 1 - Securing the SSH service