Clément Désiles
6355a9aae5
REJECT needs the nft_reject kernel extension, which is unavailable on this Arch kernel (iptables-nft reports 'Extension REJECT revision 0 not supported'), so every ban silently failed. DROP works everywhere and is quieter toward attackers.
27 lines
867 B
Markdown
27 lines
867 B
Markdown
# Fail2ban
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Bans brute-force sources via UFW. Reads logs from the systemd journal (`backend = systemd`), so it works on both Arch and Debian.
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## Jails
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- `sshd`
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- `nginx-http-auth`
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## Notes
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- Logs to the journal (`logtarget = STDOUT` in `fail2ban.local`) — see `journalctl -u fail2ban`.
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- The systemd unit is hardened (`ProtectSystem=full`); the drop-in lives at `/etc/systemd/system/fail2ban.service.d/override.conf` and is fully managed by the role.
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- Firewall/banaction is UFW on every host; jails ban via `ufw prepend deny` (DROP — no kernel `REJECT` extension needed, and it doesn't reveal the host to attackers).
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## Variables
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See [defaults/main.yml](defaults/main.yml).
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## Verify
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```bash
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sudo fail2ban-client status
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sudo fail2ban-client set sshd banip 192.0.2.1 && sudo ufw status | grep 192.0.2.1
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sudo fail2ban-client set sshd unbanip 192.0.2.1
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```
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