1. Chapter 22. Network Layer: Routing
Delivery
Forwarding
Unicast routing protocols
Multicast routing protocols
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2. Communication Networks, KWU
Autonomous Systems
A group of networks/routers under the authority of a single administration
Intradomain routing
Interdomain routing
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3. Popular Routing Protocols
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4. Communication Networks, KWU
RIP
Routing Information Protocol
Distance vector routing
Sharing knowledge about the entire autonomous system
Sharing only with neighbors
Sharing at regular intervals
Routing table
Destination
Hop Count
Next Router
Other information 7 5 4 6
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5. Distance Vector Routing
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6. RIP: Initial Routing Tables
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7. RIP: Updating Routing Table (Router A)
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8. RIP: Final Routing Tables
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9. Updating Routing Table: Example
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10. Communication Networks, KWU
OSPF
Open Shortest Path First
Link state routing
Sharing knowledge about the neighborhood
Sharing with every other router
Sharing when there is a change
LSA (Link State Advertisement)
Each router floods (distributes) LSAs to share information about their neighbors
Link state database
Every router receives LSAs from every other router
Every router has exactly the same link state database
Routing table
Every router uses the (Dijkstra) shortest path algorithm to construct the routing table
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11. Communication Networks, KWU
Link State Routing
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12. Communication Networks, KWU
OSPF: Link Cost
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13. OSPF: Link Cost in Dijkstra Algorithm
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14. Communication Networks, KWU
OSPF: LSA and LSD
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15. Communication Networks, KWU
OSPF: Flooding
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16. OSPF: Shortest Path Calculation (1)
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17. OSPF: Shortest Path Caculation (2)
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18. OSPF: Shortest Path Caculation (3)
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19. OSPF: Shortest Path Caculation (4)
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