OSPF Open Shortest Path First

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

IP Routes ip route ip route ip route ip route

IP Routes

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

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

OSPF Design

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

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

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

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

Thanks for your attention!

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