Learning Objectives

After successfully completing this section, you should be able to

  1. describe broadcast and multicast.
  2. explain how routing is done for broadcast and multicast, respectively.
  3. explain how some broadcast and multicast algorithms and protocols work.

Learning Tasks

Required:

  1. Watch the slideshow for this section.
  2. Study Section 5.3, Intra-AS Routing in the Internet: OSPF, in the textbook.

Terms and Topics

Section 3 – Intra-AS Routing in the Internet: OSPF

Autonomous Systems (ASs)
Intra-autonomous system routing protocol
Gateway routers
Inter-AS routing
Link-state protocol
Dijkstra’s least cost path algorithm Open Shortest Path First (OSPF)
IS-IS protocol as intra-AS routing protocol
RIP response message
RIP advertisements
Advances in OSPF routing (for intra-AS)
Area border routers
Backbone

Broadcast routing algorithms in practice
Multicast routing algorithms
Address indirection
Multicast group
Internet group management protocol (IGMP)
IGMP message types
Multicast routing problem
Using group-shared tree in multicast routing
Using source-based tree in multicast routing
Multicast routing in the Internet
Distance vector multicast routing protocol (DVMRP)
Protocol independent multicast (PIM) routing protocol
Source-specific multicast (SSM)

Leading Questions

  1. What is an autonomous system?
  2. By organizing routers on a large-scale network, such as the Internet, into autonomous systems, what problems are solved?
  3. What is an intra-autonomous system routing protocol?
  4. Why is intra-autonomous system routing needed?
  5. What is the Internet control message protocol (ICMP) used for?
  6. What is an autonomous system (AS)?
  7. What is an intra-AS routing protocol used for?
  8. What is the routing information protocol (RIP) used for? How does it work?
  9. How is RIP implemented in UNIX?
  10. What is the open shortest path first protocol (OSPF) used for? How does it work?
  11. What are the differences between RIP and OSPF?
  12. What advantages are embodied in OSPF Protocol?
  13. What are the different uses of internal routers, area border routers, and backbone routers?
  14. What is enhanced internal gateway routing protocol (EIGR), and how does it work?