1. COMPUTER NETWORKS
CS610
Lecture-42
Hammad Khalid Khan

2. Review Lecture 41 Routes and Data Traffic
Borger Gateway Protocol (BGP)
Routing Information Protocol (RIP)

3. RIP Packet Format

4. Illustration of RIP Packet Format

5. The Open Shortest Path

6. OSPF Characteristics Routing Within An Autonomous System
Full CIDR and Subnet Support
Authenticated Message Exchange
Imported Routes
Link-State Algorithm
Support For Multi-access Networks

7. OSPF AREAS

8. Multicast Routing

9. Link-Status in the Internet
Router corresponds to node in graph
Network corresponds to edge
Adjacent pair of routers periodically
Test connectivity
Broadcast link-status information to area
Each router uses link-status messages to compute shortest paths

10. Illustration of OSPF Graph

11. OSPF and Scale
Because it allows a manager to partition the routers and networks in an autonomous system into multiple areas, OSPF can scale to handle a much larger number of routers than other IGPs

12. Summary RIP Packet Format Open Shortest Path First (OSPF) Protocol
OSPF Graph
OSPF Areas