Routing is the process of determining the path that data packets follow to reach their destination across interconnected networks.
- It involves the use of routing tables and algorithms to decide the most efficient route for data transmission.
Types of Routing:
1.) Static Routing
- Static routing involves manually configuring specific routes on a router to direct data packets to their destinations.
- These routes do not change unless updated manually by a network administrator. Static routing is suitable for small networks with predictable traffic patterns.
2.) Dynamic Routing
- Dynamic routing automatically adjusts routes based on the current network conditions.
- Routers use dynamic routing protocols like OSPF, RIP, or EIGRP to learn and share routing information, making it adaptable to changes such as network failures or traffic congestion.
3.) Default Routing
- Default routing is used when a router is configured to forward all packets to a single default route if it does not have a specific path for the destination.
- This method is often implemented in small or stub networks where there is only one path to external networks.
Routing Protocols:
Routing protocols are sets of rules used by routers to determine the most efficient paths for data packets to travel across a network.
- These protocols share routing information among routers to build and maintain accurate routing tables.
The main types of routing protocols are:
1.) Distance Vector Protocols
Distance vector protocols determine the best route to a destination based on the distance and direction (vector). Routers exchange routing information with their immediate neighbors periodically.
- Examples: Routing Information Protocol (RIP), Interior Gateway Routing Protocol (IGRP).
Characteristics:
- Simple to implement.
- Periodic updates may lead to slower convergence and higher network overhead.
- Uses metrics such as hop count to measure the shortest path.
2.) Link-State Protocols
Link-state protocols use a map of the entire network topology to determine the shortest and most efficient path. Routers exchange link-state advertisements (LSAs) to update their view of the network.
- Examples: Open Shortest Path First (OSPF), Intermediate System to Intermediate System (IS-IS).
Characteristics:
- Faster convergence compared to distance vector protocols.
- Considers multiple factors, such as bandwidth and latency, for determining the best route.
- Suitable for large and complex networks.
3.) Hybrid Protocols
Hybrid protocols combine features of both distance vector and link-state protocols to optimize routing. They use aspects of link-state’s efficiency and distance vector’s simplicity.
- Examples: Enhanced Interior Gateway Routing Protocol (EIGRP).
Characteristics:
- Offers faster convergence than distance vector protocols.
- Reduces network overhead by limiting updates to changes in the network.
- Balances efficiency and scalability for medium-to-large networks.
Multicasting
Multicasting is a method of delivering a single packet to multiple recipients simultaneously.
- Reduces bandwidth consumption compared to sending individual packets to each recipient.
- Used in applications like video conferencing and streaming.
The Anatomy of a Router
A router is a networking device that forwards data packets between different networks.
Its key components include:
1.) Routing Table
- Stores information about network paths and destinations.
2.) Forwarding Mechanism
- Determines the next hop for each packet based on the routing table.
3.) Control Plane
- Manages routing decisions and maintains routing protocols.
4.) Data Plane
- Handles the actual forwarding of packets.
5.) Interfaces
- Physical or virtual connections to other networks or devices (e.g., Ethernet ports).
