Routing in networking determines how data moves from one computer to another across a network. There are two main types of routing: static and dynamic.
| Static Routing | Dynamic Routing | |
| How It Works: | · Routes are manually set by network administrators. · Fixed paths are defined for data to travel. | · Routers automatically discover and adjust routes. · Uses algorithms to find the best path based on current network conditions. |
| Advantages: | · Simplicity: Easy to configure and understand. · Control: Precise control over the path data takes. · Security: Less exposure to routing-based attacks as routes don’t change automatically. | · Adaptability: Automatically adapts to network changes like outages or added routes. · Scalability: Handles large and complex networks efficiently. · Reduced Management: Less manual configuration needed compared to static routing. |
| Usage Areas: | · Small Networks: Few devices and simple configurations. · Stable Networks: Where the network topology doesn’t change frequently. · Security-Sensitive Environments: Environments needing tight control over traffic paths. | · Large Networks: With frequent changes and complex configurations. · Dynamic Environments: Where network topology changes often, such as with mobile devices or fluctuating loads. · Enterprises and ISPs: Where maintaining optimal routing with minimal manual intervention is crucial. |
| Use Cases: | Best for small, simple, and stable networks where manual configuration is manageable and beneficial for control and security. | Ideal for large, complex, and changing networks where automatic route adjustment and scalability are needed to maintain efficiency and reliability. |
Overall, static routing offers simplicity and control for stable environments, while dynamic routing provides adaptability and efficiency for complex and evolving networks.
Dynamic Routing
Dynamic routing protocols are essential in computer networks for automatically discovering and maintaining the most efficient paths for data transmission between routers. They adapt to network changes in real-time, ensuring optimal routing without manual intervention. Here’s an overview of their key features and types:
Key Features
- Automatic Updates: Dynamic routing protocols periodically exchange routing information to update routing tables. This helps in adapting to changes such as link failures or network congestion.
- Scalability: They support large and complex networks by dynamically adjusting routes as new routers are added or removed.
- Fault Tolerance: These protocols reroute traffic in case of a failure, maintaining network availability and reliability.
| Dynamic Protocols | Interior /Exterior | Type | Metric | Port | Administrative Distance | Algorithm |
| Routing Information Protocol (RIP) | IGP | Distance vector | Hop count (cannot exceed 15 hops) | UDP (port 520 or 521) | 120 | Bellman-Ford or distance-vector |
| Open Shortest Path First (OSPF) | IGP | Link state | Cost (based on bandwidth) | Native IP (89) | 110 | Dijkstra’s shortest path first algorithm |
| Enhanced Interior Gateway Routing Protocol (EIGRP) | IGP | Distance vector /Hybrid | Composite (bandwidth and delay by default) | Native IP (88) | int.90 ext.170 | Diffusing Update Algorithm (DUAL) |
| Border Gateway Protocol (BGP) | EGP | Path vector | Path attributes | TCP (port 179) | ext.20 int.200 | Best Path Selection Algorithm |
| Intermediate System-to-Intermediate System (IS-IS) | IGP | Link state | Cost (based on bandwidth) | Layer2 frames LLC encapsulation | 115 | Dijkstra’s shortest path first algorithm |
| Local interface/Directly connected | 0 | |||||
| Static route | 1 | |||||
| Unknown | 255 | |||||
Main Types of Dynamic Routing Protocols
- Distance Vector Protocols
- Description: Use distance to determine the best path to a destination. Each router shares its routing table with its immediate neighbors at regular intervals.
- Examples:
- RIP (Routing Information Protocol): Simplistic, suitable for small networks, with a maximum hop count of 15.
- Usage: Best for simple, smaller networks where changes are infrequent.
- Link State Protocols
- Description: Each router constructs a complete map of the network’s topology, using this map to determine the shortest path to every destination.
- Examples:
- OSPF (Open Shortest Path First): Widely used in large and complex enterprise networks, provides rapid convergence and scalability.
- IS-IS (Intermediate System to Intermediate System): Similar to OSPF but often used in larger provider networks.
- Usage: Ideal for large and hierarchical networks needing fast adaptation to topology changes.
- Path Vector Protocols
- Description: Maintain the path information that gets updated dynamically. This is typically used for inter-domain routing.
- Examples:
- BGP (Border Gateway Protocol): Manages routing between different autonomous systems on the internet, emphasizing policy-based routing.
- Usage: Crucial for routing between different networks or ISPs, forming the backbone of internet routing.
- Hybrid Protocols
- Description: Combine features of distance vector and link state protocols, offering both efficient route determination and fast convergence.
- Examples:
- EIGRP (Enhanced Interior Gateway Routing Protocol): Cisco proprietary, combines the best of distance vector and link state protocols for efficient and fast routing.
- Usage: Suitable for complex and dynamic enterprise networks requiring a balance of performance and simplicity.
Routings Usage in Networks
- LANs and Enterprise Networks: OSPF and EIGRP are commonly used for their ability to handle large, complex topologies efficiently.
- WANs and Service Providers: IS-IS and BGP are preferred for managing large-scale networks and routing between different organizations or ISPs.
- Simple Networks: RIP can be used where network simplicity outweighs the need for rapid convergence or scalability.
Dynamic routing protocols enhance network resilience and performance by automating route management, making them essential in modern networking for maintaining efficient and reliable data transmission paths.
