Chapter 4-5 - Part2

Question 1

What is traditional destination-based forwarding?

Answer 1

matching each destination one by one, by giving a range of address and then depending on that range, sends to a link interface

Question 2

What is longest prefix matching?

Answer 2

Use the LONGEST address prefix that matches destination address.

Question 3

Centralized vs Decentralized Routing Rhythm classification

Answer 3

Centralized (Global): all routers have complete topology, info

Decentralized: iterative process of computation, exchanging info with neighbors

Question 4

Explain Dijkstra’s Algorithm from a single source

Answer 4

1. Find closest unchecked node (v) to source.
2. Find all unchecked nodes of (v). Update Distance if shorter
3. Repeat step 1.

Question 5

What’s a problem with Dijkstra’s algorithm?

Answer 5

Route oscillations are possible.

Question 6

Explain Bellman Ford Algorithm

Answer 6

Include:

1. Direct Path from source to node
2. Any neighboring node of a neighbor

Question 7

Explain Distance Vector Algorithm. When does it send updates to neighboring nodes?

Answer 7

Each node:

1. waits for change in link cost
2. recompute DV
3. Will only send updates if DV changes!