change F2B configs: made config more aggressive (#3243)

docs/content/config/security/fail2ban.md

@@ -4,7 +4,7 @@ hide:
   - toc # Hide Table of Contents for this page
 ---
 
-Fail2Ban is installed automatically and bans IP addresses for 3 hours after 3 failed attempts in 10 minutes by default.
+Fail2Ban is installed automatically and bans IP addresses for 1 week after 2 failed attempts in a time frame of 1 week by default.
 
 ## Configuration files
 

target/fail2ban/jail.local

@@ -1,14 +1,14 @@
 [DEFAULT]
 
 # "bantime" is the number of seconds that a host is banned.
-bantime = 3h
+bantime = 1w
 
 # A host is banned if it has generated "maxretry" during the last "findtime"
 # seconds.
-findtime = 10m
+findtime = 1w
 
 # "maxretry" is the number of failures before a host get banned.
-maxretry = 3
+maxretry = 2
 
 # "ignoreip" can be a list of IP addresses, CIDR masks or DNS hosts. Fail2ban
 # will not ban a host which matches an address in this list. Several addresses
@@ -25,9 +25,14 @@ enabled = true
 
 [postfix]
 enabled = true
+# See https://github.com/fail2ban/fail2ban/blob/27294c4b9ee5d5568a1d5f83af744ea39d5a1acb/config/filter.d/postfix.conf#L58
+# `mode=aggressive` basically combines more filters to match more lines, and hence, apply rules
+# more aggressively. The same goes for the `postfix-sasl` jail.
+mode = aggressive
 
 [postfix-sasl]
 enabled = true
+mode = aggressive
 
 # This jail is used for manual bans.
 # To ban an IP address use: setup.sh fail2ban ban <IP>