feat(servers): secure them even more.

modules/servers/general/openssh.nix

@@ -21,8 +21,16 @@
 
   services.fail2ban = {
     enable = true;
+    maxretry = 5;
     ignoreIP = [
       "65.21.241.194"
     ];
+    bantime = "24h"; # Ban IPs for one day on the first ban
+    bantime-increment = {
+      enable = true; # Enable increment of bantime after each violation
+      multipliers = "1 2 4 8 16 32 64";
+      maxtime = "168h"; # Do not ban for more than 1 week
+      overalljails = true; # Calculate the bantime based on all the violations
+    };
   };
 }