[catkitcourt]

What’s the difference between fail2ban? Though I feel neither of those two works now.

[kemitche]

Seems similar, except that this is built-in to sshd vs having to install a separate tool. It's also enabled by default here in sshd.

[niobe]

fail2ban works just fine with sshd. I combine this GeoIP blocking ceetain troublesome locations in firewalls. 98% of my scanning / exploiting comes from 11 countries.

[bigiain]

fail2ban is great, but only works on the local host.

The post says: "Right now our perimeter firewall is blind to whether a brief SSH connection was successful or not"

(I suspect there's a way to set up centralised logging and fail2ban running looking at those centralised logs and sending updates to a perimeter firewall, but that's not a typical deployment of fail2ban. Or at least is wasn't when I was heavily using it a while back.)