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
  • Possibly linux@lemmy.zipEnglish
    5·
    22 hours ago

    The IPv6 privacy extensions are something else entirely and are not used for anything server side

    You should research IPv6 port scanning techniques. It is harder than IPv4 but still doable depending on the context. If your goal is simply to reduce network traffic due to bots that’s one thing. However, it should not be considered a security mechanism.