Network interfaces and firewall

Network interfaces

• Interfaces with addresses, state, counters and errors; the interface kind (bridge, veth, WireGuard, tunnel, libvirt) and the containers attached to it.
• Listening sockets with processes; ports open on 0.0.0.0 get a one-click port check (TCP, HTTP, TLS, curl).

Firewall

• ufw: state, numbered rules, adding and removing (port/protocol/source/comment), enabling with port 22 protection — you cannot enable the firewall without allowing SSH.
• firewalld: zones, services, ports; add and remove temporarily or permanently, reload.
• Nothing installed — ufw or firewalld is installed as a package with a live log.
• iptables is shown as is — no editing, on purpose.

Brute-force protection is a separate fail2ban section right below “Firewall”.