please add SSH trottling recipe for nftables

[perkelix]

It would be desirable for the hardening guide to include an nftables recipe to accomplish SSH trottling. Many distributions have replaced iptables with nftables as their default.

[jtesta]

As far as I know, the guides are already optimized to give admins an easy time. If I found a platform that only included nftables, then I'd switch to that instead of requiring the installation of iptables. So far, though, all the supported platforms are still shipping iptables by default.

[perkelix]

Debian has shipped nftables by default for 3 releases already. Conversely iptables has been an optional package since then.

[jtesta]

Ahh, ok. I see that the guide for Debian 12 has the user install iptables. I suppose that one can be updated to use nftables. Note that the guide for Rocky Linux 9 uses the pre-installed "firewall- cmd" tool, and Ubuntu still ships with iptables by default. So it looks like only the Debian and perhaps Amazon Linux 2023 guides can be updated.