A bastion host is a hardened, minimally configured server positioned at the network perimeter to absorb and deflect attacks before they can reach internal systems. It acts as the first point of contact for incoming traffic, protecting the servers behind it.
Bastion Host
Another thing that we could have out front protecting the rest of our network is called a bastion host.
At one point in time, we built castles, and these castles would protect us from the enemies down below. These castles would have these towers to them, and these towers would help protect the castle, because you could be up above and shoot down arrows on your enemy and make sure that they couldn't attack the castles.
Now, that was good until gunpowder came out. And then these castle walls, or specifically these towers, were a lot more susceptible now to like cannon fire. The cannon fire would hit these and they would crumble because they were hollow on the inside. So these were not as powerful with the invention of gunpowder.
So sometime later, when gunpowder became much more prevalent, they started creating bastions. Bastions are these areas that are sticking out right here. Notice that they're a lot shorter and they're a lot more reinforced, as in this is solid. These are not just skimpy little walls, but this is actually earth there, that you couldn't blow a cannonball through that because it's really thick. So bastions are these protruding areas, and generally they took this shape, but there are these protruding areas around your fort to help protect the fort. So it's the first thing you encounter: you don't encounter the wall first over here, you encounter the bastions right here.
Well, that's the same concept when it comes to a bastion host. When it comes to our networks and securing our services, we have a server out front. This is a hardened server. This is a server that doesn't have a lot of services running on it. It's very stripped down and very basic, but what is on it is a lot of reinforcements. So it's a hardened machine that's protecting all of your servers on the back end. So we call that a bastion host.
One example where we might have a bastion host is maybe this is a reverse proxy. Now, we'll get more into reverse proxy here in a little bit, but that's just one example. Or maybe it's a load balancer, and it's load balancing between these devices. So it serves two purposes here when it's a load balancer: it's a load balancer that's balancing between these devices, but also this is a hardened machine out front that, if somebody were to attack it, they would have to get to that bastion host first.
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