Transcript OSPF - Roggeweck

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 15.235.16.0 255.255.255.0 10.120.0.2
• ip route 15.235.32.0 255.255.255.0 10.120.0.3
IP Routes
OSPF History
research on the SPF algorithm
(invented by Dijkstra)
 1980s problems with RIP and large
networks
 1988
Internet Engineering Task
Force (IETF)

1970
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 : 65535
 Tree

• Router 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?