Step 1: sudo apt install fail2ban

Step 2:

sudo nano /etc/fail2ban/jail.d/guacamole-auth.conf

**Paste text below**

[DEFAULT]
banaction = cloudflare

[guacamole-auth]
enabled = true
logpath = /var/log/tomcat*/catalina.out
port = http,https
bantime = 1d
maxretry = 3


Step 3: 

sudo nano  /etc/fail2ban/filter.d/guacamole-auth.conf

**Paste text below**

[Definition]
failregex = \bAuthentication attempt from \[<HOST>(?:,.*)?\] for user ".*" failed\.
ignoreregex =



If using cloudflare continue with step 4 below

Step 4: 

sudo nano  /etc/fail2ban/action.d/cloudflare.conf

**replace the two options below**

cftoken =

cfuser =