Lecture Notes: Static vs Dynamic Routing

Overview

• Static Routing:
  • Requires manual configuration of routes on each router.
  • Suitable for networks with a small number of routers.
  • Not scalable for large networks.
• Dynamic Routing:
  • Automates the discovery and update of routes.
  • Reduces the need for manual configuration.
  • Automatically adapts to changes in the network topology.
  • Requires initial configuration of dynamic routing protocols.
  • Involves CPU and memory overhead for routers.

Dynamic Routing Protocols

• Enable routers to automatically share routing information.
• Inform other routers of known routes via multicast or direct updates.
• Adjust routing tables based on network topology changes.

Protocols Discussed:

1. EIGRP (Enhanced Interior Gateway Routing Protocol):

   • Cisco-centric, but available on some other routers.
   • Easy to set up with minimal configuration.
   • Quickly converges and identifies loops.
   • Efficient in sending updates with minimal network traffic.

2. OSPF (Open Shortest Path First):

   • Available across different manufacturers.
   • Suitable for networks within a single autonomous system (AS).
   • Link-state protocol determining best routes based on link cost (throughput, uptime).
   • Allows load balancing if costs between links are equal.

3. BGP (Border Gateway Protocol):

   • Used for routing between different autonomous systems.
   • Essential for internet routing and wide area networks.
   • Known as the protocol that connects the internet.

Considerations for Choosing a Protocol

• Routing Decision Factors:
  • Link state (up or down), hop count, connection speed.
• Protocol Suitability:
  • EIGRP for Cisco environments.
  • OSPF for mixed environments or single AS.
  • BGP for broader internet connectivity.

Key Takeaways

• Dynamic routing significantly reduces the administrative burden of managing routing tables.
• Proper planning and understanding of protocols are crucial for effective implementation.
• Dynamic routing offers adaptability and efficiency, vital for modern network infrastructures.