✅ What Are Routing Protocols?

Routing protocols are rules and algorithms that routers use to determine the best path for forwarding data across a network. They enable routers to communicate with each other, exchange information about network topology, and dynamically adjust routes when network conditions change.

🚀 Types of Routing Protocols

Routing protocols can be broadly classified into three categories:

1. Distance Vector Protocols
2. Link-State Protocols
3. Hybrid Protocols

✅ 1. Distance Vector Protocols

• How It Works:
  Routers share their routing tables with directly connected neighbors. They determine the best path based on “distance” (usually the number of hops).
• Key Features:
  • Simple to configure
  • Slower convergence (time to update routes after a change)
  • Prone to routing loops without safeguards
• Common Protocols:
  • RIP (Routing Information Protocol): Uses hop count as a metric (max 15 hops).
  • IGRP (Interior Gateway Routing Protocol): Developed by Cisco, considers bandwidth and delay.

✅ 2. Link-State Protocols

• How It Works:
  Routers create a complete map of the network and share updates with all routers in the area. They use algorithms like Dijkstra’s algorithm to calculate the shortest path.
• Key Features:
  • Fast convergence
  • Scalable and efficient in large networks
  • Consumes more CPU and memory compared to distance vector protocols
• Common Protocols:
  • OSPF (Open Shortest Path First): Widely used in enterprise networks, supports VLSM and route summarization.
  • IS-IS (Intermediate System to Intermediate System): Similar to OSPF, often used in large service provider networks.

✅ 3. Hybrid Protocols

• How It Works:
  Combines features of both distance vector and link-state protocols. They balance efficiency with scalability.
• Key Features:
  • Fast convergence
  • Supports complex routing policies
  • Scalable for large networks
• Common Protocols:
  • EIGRP (Enhanced Interior Gateway Routing Protocol): Cisco proprietary, uses both distance vector and link-state concepts.
  • BGP (Border Gateway Protocol): The protocol that powers the Internet, controlling data flow between different organizations (autonomous systems).