merged

content/fundamentals/ssh.md

@@ -26,6 +26,7 @@ approaches for day to day use and troubleshooting.
 
 ## Prerequisites
 
+
 The SSH ecosystem is very established. It is available on all modern GNU/Linux
 distributions, MacOS and Windows. You can use your home server or if you don't have one yet you can use your own personal laptop to experiment (in this case, your laptop will
 play the role of both the server and client as explained later).
@@ -68,7 +69,7 @@ To install the SSH server on your home server, run:
 $ sudo apt install -y openssh-server
 ```
 
-And from your client (laptop or otherwise), run:
+And on your client, run:
 
 ```bash
 $ sudo apt install -y openssh-client
@@ -323,7 +324,7 @@ Here are some questions to ask yourself:
 
   * Is your public key registered on the server in the `$HOME/.ssh/authorized_keys` folder?
 
-  * Are the folder permissions correct? (see this [SO thread](https://superuser.com/questions/215504/permissions-on-private-key-in-ssh-folder))
+  * Are the `$HOME/.ssh` permissions correct? (see this [SO thread](https://superuser.com/questions/215504/permissions-on-private-key-in-ssh-folder))
 
   * Is the SSH server running? (`sudo systemctl status sshd`)
 
@@ -333,13 +334,18 @@ Here are some questions to ask yourself:
       changes. After validating, always restart the SSH server after
       making configuration changes
 
+  * What does `sudo tail -f /var/log/auth.log` say?
+    * Every time an SSH client attempts to connect, a log
+      entry will be put into this file. Some hint as to why
+      it is failing should be here.
+
 ### On the client
 
 Here are some questions to ask yourself:
 
   * What does `ssh -vvvvv myhomebrewserver` tell you?
 
-  * Are the folder permissions correct? (see this [SO thread](https://superuser.com/questions/215504/permissions-on-private-key-in-ssh-folder))
+  * Are the `$HOME/.ssh` folder permissions correct? (see this [SO thread](https://superuser.com/questions/215504/permissions-on-private-key-in-ssh-folder))
 
   * Is the SSH server available at the port you expect? (`sudo nmap -p 22 myhomebrewserver`)