BeKind Stakepools Online runs its pool BKIND according to its principles. The configuration is fully redundant. The relay nodes and the core nodes (one active and one passive) run on their own bare metal dedicated machines locally. Only the relay nodes are reachable via the internet (via two dedicated fiber lines), which both have their own hardware firewall. The core nodes are (BKIND is) totally isolated from the internet and can only communicate with their (its) local relay nodes.
The nodes of BKIND are running on four HP Proliant Microservers and are protected by two professional DrayTek hardware firewalls. The HP Proliant Microservers are running on Ubuntu Server 20.04 LTS and are security hardened. The connection to and from the internet (and with that to and from the Cardano Blockchain) is established through two separate (physical) fiber lines. Each line has its own internet provider, to make sure BKIND remains online. Long story short, all is redundant, to make sure BKIND remains online 24/7, 365/364.
Last but not least, the configuration of BKIND is energy efficient. The total power consumption of all devices supporting BKIND is below 150 watts. During daytime this power is generated and supplied by solar panels.