- Link State Routing is a different DVR as in link-state routing each node has information about the entire topology of its domain.
- It means each node knows how other nodes are connected, what is the cost metric and so on.
- You can understand it like, everyone in the city has the same map but to reach the same destinations they take a different route.
- Dijkstra Alorotham is used to make the routing table.
- Flooding is used here to send information.
Because of flooding:
The shortest path is guaranteed.
Flooding of LSPs After a node has prepared an LSP, it must be disseminated to all other nodes, not only to its neighbors. The process is called flooding and based on the following:
1. The creating node sends a copy of the LSP out of each interface.
2. A node that receives an LSP(link-state packet) compares it with the copy it may already have. If the newly arrived LSP is older than the one it has (found by checking the sequence number), it discards the LSP. If it is newer, the node does the following:
- a. It discards the old LSP and keeps the new one.
- b. It sends a copy of it out of each interface except the one from which the packet arrived. This guarantees that flooding stops somewhere in the domain (where a node has only one interface).
Difference between DVR and LSR
|Distance Vector Routing||Link State Routing|
|1. Local knowledge||1.Global knowledge.|
|2. Bandwidth requirement is less||2. High Bandwidth is required.|
|3. Bellman ford||3.Dijkstra Algorithm.|
|4. Traffic is less||4. Because of flooding traffic is high.|
|5.Converges slowly||5. Converges fast|
|6. RIP is protocol||6. Open Shortest Path First(OSPF) is protocol|
|7. Count to infinity problem is heer||7. No count to Infinity.|
|8. Persistence loops.||8.Transient loops.|
|9. Converges slow.||9. Converges fast.|