A botnet is a group of internet-connected devices controlled by someone without the owners’ permission. The devices might be computers, phones, routers, cameras, or other connected hardware. The interesting part is how those devices receive instructions. That structure is what creates different botnet models.

Centralized Botnet Models

The older and simpler approach uses a central command server. In this setup, infected devices connect back to one place to receive instructions. The person controlling the botnet sends a command there, and the server passes it to the infected machines.

It feels tidy from the attacker’s side. One control point makes management easier, but it also creates an obvious weakness. Take down the command server and the botnet can lose its ability to coordinate.

Command and Control Servers

This model is often called a C2 architecture. The infected devices periodically contact the server and ask what they should do next. Because the server acts as the middleman, defenders can sometimes spot unusual traffic heading toward a known domain or IP address.

That weakness is why relying on one server isn’t exactly a brilliant long-term design. Attackers eventually looked for ways to spread control around.

Peer-to-Peer Botnets

A peer-to-peer, or P2P, botnet doesn’t depend on one central server. Instead, infected devices communicate with other infected devices. Commands can move through the network, making the whole system harder to shut down.

Hybrid Models

• A single C2 server is easy to understand, but losing it can seriously disrupt the botnet.

• P2P architecture spreads communication across infected devices, which makes the network harder to dismantle.

• Hybrid designs add another layer of resilience, although that extra complexity also creates more moving parts for the attacker.

Other Ways Botnets Are Organized

Botnets can also be described by how control information travels. Some use a direct connection between the controller and infected devices. Others pass instructions through several layers, so the original source is harder to identify.

DNS-based systems are another variation. A compromised device may look up a domain to discover where it should connect. Change the domain’s destination and the controller can redirect traffic without rebuilding every infected machine.

Why the Model Matters

The botnet model affects how defenders investigate and disrupt it. A centralized network gives security teams a clear place to look. A P2P network spreads that problem across many connections. A hybrid setup sits somewhere between the two, depending on how its communication system has been built.

So when someone says “botnet,” there isn’t one fixed blueprint hiding underneath. The architecture depends on how the operator wants infected devices to communicate and how much resilience they need.

The Bigger Picture

The basic idea hasn’t changed much. Someone wants control over a large collection of compromised devices, and the model determines how that control travels.

What changes is the shape of the network. Centralized models are straightforward. P2P models are more distributed. Hybrid systems try to take useful parts from both approaches.