📚 Quick Study Guide: Routing Protocols
- 🔍 What are Routing Protocols? These are sets of rules that routers use to communicate with each other, exchange information about reachable networks, and select the best paths for data packets to travel across the internet or within an organization's network.
- 🗺️ Key Functions: Routing protocols enable routers to discover new routes, maintain routing tables, choose optimal paths based on specific metrics, and adapt to changes in network topology.
- ⚖️ Routing Metrics: Routers use metrics to determine the 'best' path. Common metrics include hop count (for RIP), bandwidth, delay, reliability, and load (for OSPF, EIGRP). Lower metric values generally indicate a better path.
- 🔄 Distance-Vector Protocols: Routers using this type of protocol share their entire routing table with directly connected neighbors. They rely on neighbors to provide accurate information. Examples include RIP (Routing Information Protocol) and IGRP (Interior Gateway Routing Protocol - now largely obsolete), and EIGRP (Enhanced Interior Gateway Routing Protocol - often considered a hybrid).
- 🔗 Link-State Protocols: Routers build a complete topological map of the network. They achieve this by sending small updates called Link-State Advertisements (LSAs) to all other routers within the same area. Examples are OSPF (Open Shortest Path First) and IS-IS (Intermediate System to Intermediate System).
- 🌐 Path-Vector Protocol: BGP (Border Gateway Protocol) is the only path-vector protocol in widespread use. It's primarily used for inter-domain routing (between Autonomous Systems) on the global internet, focusing on paths, policies, and attributes rather than just metrics.
- 🚪 Interior Gateway Protocols (IGPs): These protocols operate *within* a single Autonomous System (AS). Examples include RIP, OSPF, EIGRP, and IS-IS.
- 🌍 Exterior Gateway Protocols (EGPs): These protocols are used to route traffic *between* different Autonomous Systems (ASes). BGP is the sole EGP currently in use.
🧠 Practice Quiz: Routing Protocols
1. Which of the following is a characteristic of a Distance-Vector routing protocol?
A. Routers build a complete topological map of the network.
B. Updates are sent only when a change in the network occurs.
C. Routers share their entire routing table with directly connected neighbors.
D. It calculates the shortest path using Dijkstra's algorithm.
2. OSPF (Open Shortest Path First) is an example of which type of routing protocol?
A. Distance-Vector
B. Path-Vector
C. Link-State
D. Hybrid
3. What is the primary metric used by RIP (Routing Information Protocol) to determine the best path?
A. Bandwidth
B. Delay
C. Hop count
D. Reliability
4. Which protocol is primarily used for routing between different Autonomous Systems (AS) on the internet?
A. OSPF
B. EIGRP
C. RIP
D. BGP
5. A router using a Link-State protocol typically maintains which of the following?
A. Only its directly connected routes.
B. A complete topological database of the network.
C. Only routes learned from a single next-hop router.
D. A list of all active user sessions.
6. EIGRP (Enhanced Interior Gateway Routing Protocol) is often classified as a hybrid routing protocol because it combines features of both:
A. Static and dynamic routing.
B. IPv4 and IPv6 routing.
C. Distance-Vector and Link-State protocols.
D. Interior and Exterior Gateway protocols.
7. Which of these is NOT an Interior Gateway Protocol (IGP)?
A. RIP
B. OSPF
C. BGP
D. EIGRP
Click to see Answers
1. C. Routers share their entire routing table with directly connected neighbors.
2. C. Link-State
3. C. Hop count
4. D. BGP
5. B. A complete topological database of the network.
6. C. Distance-Vector and Link-State protocols.
7. C. BGP
