Hey all, i’ve decided I should probably setup something else to help block nefarious IP addresses. I’ve been looking into CrowdSec and Fail2Ban but i’m not really sure the best one to use.

My setup is OpnSense -> Nginx Proxy Manager -> Servers. I think I need to setup CrowdSec/Fail2Ban on the Nginx Proxy Manager to filter the access logs, then ideally it would setup the blocks on OpnSense - but i’m not sure that can be done?

Any experience in a setup like this? I’ve found a few guides but some of them seem fairly outdated.

Edit: thanks everybody for the great info. General consensus seems to be with crowdsec so I’ll go down that path and see how it goes.

  • irmadlad@lemmy.worldEnglish
    131·
    18 hours ago

    As you probably know the crowdsec bouncer doesn’t directly parse logs or do checks like F2B filters. It queries the crowdsec LAPI for decisions and applies them. The “allowed” or “whitelisted” IP logic is handled at the Security Engine or LAPI level, not by the bouncer itself.

    You can whitelist an ip in /etc/crowdsec/whitelists.yaml or even whitelist decisions in the whitelist.yaml as such:

    name: private-ips
description: Whitelist local and private IPs
whitelist:
  reason: "Allow local and private IPs"
  ip:
    - "127.0.0.1"
    - "192.168.1.0/24"
  cidr:
    - "10.0.0.0/8"

    Then issue sudo systemctl reload crowdsec. Kind of the same concept as F2B’s ignoreip option. If you are using Tailscale to administer the server, then it’s easier to whitelist. IIRC, you can use cscli decisions add --type whitelist --ip 192.168.1.100 --duration 1y but it doesn’t add them to the whitelist.yaml. Instead it keeps them in crowdsec’s database managed by LAPI. To undo: cscli decisions delete --ip 192.168.1.100 --type whitelist

    https://docs.crowdsec.net/u/getting_started/post_installation/whitelists/