1. OSPF Open Shortest Path First

2. Table of Content  IP Routes  OSPF History  OSPF Design  OSPF Link State  OSPF Routing Table  OSPF Data Packets

3. IP Routes ip route 15.235.16.0 255.255.255.0 10.120.0.2ip route 15.235.16.0 255.255.255.0 10.120.0.2 ip route 15.235.32.0 255.255.255.0 10.120.0.3ip route 15.235.32.0 255.255.255.0 10.120.0.3

4. IP Routes

5. OSPF History  1970 research on the SPF algorithm (invented by Dijkstra)  1980s problems with RIP and large networks  1988 Internet Engineering Task Force (IETF)

6. OSPF Design  Division into star of areas  All areas are connected to backbone  area 0  Traffic between areas have to pass area 0  Critical if the network of area 0 fails  High bandwith required

7. OSPF Design

8. Table of Content  IP Routes  OSPF History  OSPF Design  OSPF Link State  OSPF Routing Table  OSPF Data Packets

9. OSPF Link State  Uses „Hello“ Messages to identify neighbours  Neighborhood is formed & Routing Tables are build  Dijkstra's SPF algorithm

10. OSPF Routing Table  Number of hops : 65535  Tree Router is the rootRouter is the root  Metrics  Multipath Routing

11. OSPF Data Packets Type: Hello Database description Link-state request Link-state update Link-state acknowledgment

12. Thanks for your attention!

13. Questions  Of what type can OSPF Data Packets be?  What is critical about area 0?