Network Topology

Network Topology

🌐 What Is Network Topology?

Network topology refers to the physical or logical layout of devices and connections in a network. It’s how computers, switches, routers, and cables are arranged and interact.

There are two types:

- Physical topology: actual layout of cables and devices.

- Logical topology: how data flows across the network.

---

🧩 Common Topologies You Need to Know

1. Bus Topology

All devices share a single backbone cable. Data travels in both directions, and terminators are needed at each end.

> 🔑 Remember: Simple, cheap, but one break can bring down the whole network. Rarely used today.

---

2. Star Topology

All devices connect to a central hub or switch. If one device fails, others stay online.

> 🔑 Remember: Most common today. Easy to manage. But if the central device fails, the whole network goes down.

---

3. Ring Topology

Devices form a closed loop. Data travels in one direction (or both in dual ring). Each device acts as a repeater.

> 🔑 Remember: Used in older token ring networks. One break can disrupt the loop unless it's dual ring.

---

4. Mesh Topology

Every device connects to every other device. Can be full mesh (all connected) or partial mesh.

> 🔑 Remember: High redundancy and fault tolerance. Used in WANs and backbone networks. Expensive and complex.

---

5. Hybrid Topology

Combines two or more topologies (e.g., star-bus, star-ring). Common in large enterprise networks.

> 🔑 Remember: Flexible and scalable. Real-world networks are often hybrids.

---

🛡️ Security+ Focus Points

- Star topology is dominant in LANs—know how switches and hubs behave.

- Mesh topology is key in WANs and disaster recovery—think of BGP and redundant paths.

- Bus and ring are mostly historical—understand them for legacy systems and exam questions.

- Hybrid is the reality—expect mixed environments in enterprise setups.