Routing Protocols

OSPF

(Open Shortest Path First)

- Link-state protocol

-Smaller Overhead, but small throughput

-Good Scalability, Fast Convergence

-Redundant (if one link goes down, reroute automatically)

-Bandwidth used as metric

- single autonomous system use (AS is a group of devices you control~~~)

BGP

(Border-Gateway Protocol - “three napkins“)

• Distance-vector based

• In between networks (over large areas)

• Average converge speed via network policy

• Move between autonomous networks

• selecting the best path route path based on network policies and path attributes like AS path length, local preference, and origin code

• metric based on lower IGP (interior gateway)

• classless

EIGRP (and its details & Cisco based)

• Hybrid of link state and distance vector

• rapid convergence

• EIGRP metrics include bandwidth, delay, load, reliability, and Maximum Transmission Unit (MTU)

• automatic summarization (smaller route table)

• Redundant

• minimal overhead

• lot of bandwidth to use, but it uses small bandwidth itself

• classless

RIPv2

(use for small-simple networks otherwise ospf )

• Metric based on hops

• Distance-vector based

• classless (v1 is class based)

• Smaller network use (low scalability), ease of use

• lower convergence speed

IS-IS

• IS-IS is better suited for large-scale service provider and backbone networks. Its architecture and scalability make it more effective in environments that require handling a massive amount of routing data and multiple routing levels.

• If you're operating in an environment with thousands of routers (like an ISP or large enterprise backbone), IS-IS tends to scale better due to less flooding and overhead compared to OSPF.