What are the different types of routing protocols?

Routing protocols are essential components of computer networks that enable the exchange of routing information among routers, facilitating the efficient forwarding of data packets from source to destination. These protocols can be categorized into different types based on various criteria such as the method of information exchange, network size, and routing behavior.

  1. Interior Gateway Protocols (IGPs):
    • Distance Vector Protocols:
      • Description: Distance Vector protocols determine the best path to a destination based on the number of hops or distance.
      • Example Protocols: Routing Information Protocol (RIP), Interior Gateway Routing Protocol (IGRP).
      • Technical Details: Routers exchange routing tables periodically, and each router advertises its routes to its neighbors. The routers update their routing tables based on the received information.
    • Link-State Protocols:
      • Description: Link-State protocols build a detailed map of the network by exchanging information about the state of each link.
      • Example Protocols: Open Shortest Path First (OSPF), Intermediate System to Intermediate System (IS-IS).
      • Technical Details: Routers exchange link-state advertisements containing information about the state and cost of each link. This information is used to build a complete topological map of the network, and routers calculate the shortest path to each destination.
  2. Exterior Gateway Protocols (EGPs):
    • Border Gateway Protocol (BGP):
      • Description: BGP is the primary EGP used on the Internet, and it's designed for routing between different autonomous systems (AS).
      • Technical Details: BGP routers exchange information about the reachability of IP prefixes. BGP uses path attributes and policies to determine the best route.
  3. Hybrid Routing Protocols:
    • Enhanced Interior Gateway Routing Protocol (EIGRP):
      • Description: EIGRP combines features of both distance vector and link-state protocols.
      • Technical Details: EIGRP routers exchange partial routing tables and use a metric that incorporates factors like bandwidth, delay, reliability, and load.
  4. Routing Information Protocol (RIP):
    • Description: RIP is one of the oldest routing protocols and falls under the distance vector category.
    • Technical Details: RIP routers exchange their routing tables every 30 seconds, and they use a hop count as the metric. RIP has limitations, such as the maximum hop count of 15.
  5. Open Shortest Path First (OSPF):
    • Description: OSPF is a link-state protocol designed for larger and more complex networks.
    • Technical Details: OSPF routers establish adjacencies and exchange link-state information, creating a detailed map of the network. OSPF uses Dijkstra's algorithm to calculate the shortest path.
  6. Intermediate System to Intermediate System (IS-IS):
    • Description: IS-IS is another link-state protocol commonly used in larger networks, especially in service provider environments.
    • Technical Details: IS-IS routers exchange link-state information to build a complete topology of the network. It uses the SPF (Shortest Path First) algorithm for route calculation.