So it’s my first time setting up a VPS. Is it to be expected to ban 54 IPs over a 12h timespan? The real question for me is whether this is normal or too much.

$ sudo fail2ban-client status sshd
Status for the jail: sshd
|- Filter
|  |- Currently failed: 3
|  |- Total failed:     586
|  `- Journal matches:  _SYSTEMD_UNIT=ssh.service + _COMM=sshd
`- Actions
   |- Currently banned: 51
   |- Total banned:     54
   `- Banned IP list:   [list of IPs]

fail2ban sshd.conf

$ sudo cat /etc/fail2ban/jail.d/sshd.conf 
[sshd]
enabled = true
mode = aggressive
port = ssh
backend = systemd
maxretry = 3
findtime = 600
bantime = 86400

I have disabled SSH login via password. And only allow it over an SSH key.

$ sudo sshd -T | grep -E -i 'ChallengeResponseAuthentication|PasswordAuthentication|UsePAM|PermitRootLogin'
usepam no
permitrootlogin no
passwordauthentication no
  • pHr34kY@lemmy.worldEnglish
    91·
    18 days ago

    They’re portscanning bots.

    I made SSH IPv6-only and it stopped. You can’t scan IPv6 space for open ports.

  • bizdelnick@lemmy.mlEnglish
    4·
    18 days ago

    Yes, it is normal.

    # fail2ban-client status sshd
Status for the jail: sshd
|- Filter
|  |- Currently failed: 10
|  |- Total failed:     4433
|  `- Journal matches:  _SYSTEMD_UNIT=ssh.service + _COMM=sshd
`- Actions
   |- Currently banned: 27
   |- Total banned:     668
   `- Banned IP list:   2.57.122.194 45.148.10.183 195.178.110.30 2.57.122.208 92.118.39.195 103.74.123.88 92.118.39.23 2.57.122.196 92.118.39.197 45.148.10.151 92.118.39.236 178.20.210.185 68.178.161.186 80.94.92.183 92.118.39.63 2.57.122.197 2.57.122.191 2.57.122.189 80.94.92.171 94.156.152.18 14.225.7.70 45.78.198.199 211.253.9.160 159.224.213.138 1.214.42.172 103.239.165.114 77.239.111.233
  • Bloefz@lemmy.worldEnglish
    4·
    18 days ago

    That’s not a lot even. I’ve seen much worse. Also with password disabled. Some idiot bots still try to send it whole password lists.

    Just move your SSH to another port, that is enough to get rid of most of the nuisance scans. Or allow SSH only on IPv6. That usually covers it (The IPv6 address space is too big to scan, unless you have a TLD directly pointing to your IPv6)

    What I personally do is run an overlay VPN like tailscale and allow SSH in only via that.

    • irmadlad@lemmy.worldEnglish
      1·
      18 days ago

      What I personally do is run an overlay VPN like tailscale and allow SSH in only via that.

      Same. I use Tailscale as an overlay on the pFsense box and the server itself.

  • nonentity@sh.itjust.worksEnglish
    3·
    18 days ago

    Rookie numbers.

    My favourite f2b rule is the one strike ban on SSH root login attempts. Any IP originating a SSH root login attempt is clearly compromised, and gets black holed on all my hosts for a month.

    Note: direct SSH login isn’t permitted at all, the daemon is exposed purely to log the attempts.

      • nonentity@sh.itjust.worksEnglish
        2·
        18 days ago

        The actual span is a random period between 2 and 4 weeks, it’s interesting to watch how long it takes for attempts to resume.

        I prefer a more granular visibility, repeat offenders automagically ratchet up their stay in the sin bin.

  • irmadlad@lemmy.worldEnglish
    1·
    18 days ago

    Just 54? Those are rookie numbers bro. You need to open up a few more ports. LOL Honestly tho, seems pretty standard. You could change the SSH port which might lower some of the noise but bots now days are pretty sophisticated and it would be trivial to just scan your server and find out which port is SSH. If you want to stop tailing fail2ban nervously on the daily, you could use the hosts.allow/hosts.deny which would lock it down even further. Just remember to set host.allow first then host.deny. You could also deploy any number of secondary security packages like CrowdSec, Wazuh, et al.