This document discusses routing protocols in computer networks. It defines distance vector routing and link state routing, describing how each determines the best path. Distance vector routing uses hop count as a metric and shares routing tables, while link state routing shares information about network reachability and metrics. The document provides examples of how distance vector and Dijkstra's algorithm work through updating routing tables. It outlines characteristics of routers and compares advantages and disadvantages of the two routing approaches.

1. Topic Name : Routing
(distance vector & link state)
Group Name: Ethernet

2. 152-15-6232 [ Md. Touhidur Rahman]
152-15-6235 [Hasan Md. Sad Abdullah]
Group Member 152-15-6236 [Sree Joyanto Chandro Barmon]
152-15-6237 [ Tusher Chandra Ghosh]
152-15-6229 [Md. Saddam Hossain]

3. Index
• Definition
• How it’s work
• Characteristics of Routers
• Algorithm
• Example
• Advantage & Disadvantage
• Reference
• Question Session

4. A computer network is a set of computers connected together for
the purpose of sharing resources.
Computer Network
Routing Routing is the process of selecting best paths in a network
Definition

5. Distance vector
Distance vector routing is a simple routing protocol used in
packet-switched networks that utilizes distance to decide the
best packet forwarding path. Distance is typically represented
by the hop count.
Definition

6. Link state routing is a complex routing technique in which
each router shares information with other routers about the
reachability of other networks and the metric to reach the
other networks in order to determine the best path
Link state
Definition

8. Characteristics of Routers
1. Routers are multiport devices with high - speed backbones.
2. Routers also support filtering and encapsulation like bridges.
3. Like bridges routers are also self-learning, as they can
communicate their existence. to other devices and can learn
of the existence of new routers, nodes and LAN segments.
4. They typically provide some level of redundancy so that they
are less susceptible to catastrophic failure.
5. Routers constantly monitor the condition of the network, as a
whole to dynamically adapt to changes in the condition of the
network

9. DistanceVector Algorithme

10. Dijkstra’s algorithm:
 topology and link costs known to all nodes
o accomplished via “link state broadcast”
o
o all nodes have same info
 computes least cost paths from one node (source) to all
other nodes
o gives forwarding table for that node
 iterative: after k iterations, know least cost path to k
destination nodes
Link-State (LS) Routing Algorithm

11. S D(B),P(B) D(C),P(C) D(D),P(D) D(E),P(E)
A 3,A 4,A ∞ ∞
AB 3,A 4,A 8,B 12,B
ABC 3,A 4,A 5,C 12,B
ABCD 3,A 4,A 5,C 9,D
ABCDE 3,A 4,A 5,C 9,D
Example

12. Now the Shortest Path:

13. Working Procedure
1. This step calculates shortest distances. Do following |V|-1
times where |V| is the number of vertices in given graph.
2. This step initializes distances from source to all vertices as
infinite and distance to source itself as 0.
Do following for each edge u-v
(i) If dist[v] > dist[u] + weight of edge uv, then update
dist[v]
(ii) dist[v] = dist[u] + weight of edge uv
3. This step reports if there is a negative weight cycle in graph.
Do following for each edge u-v
I. If dist[v] > dist[u] + weight of edge uv, then “Graph
contains negative weight cycle”
DistanceVector Routing

14. InitialtableofA UpdatetableofA
To Cost Next
B 3 -
C 4 -
D ∞ -
E ∞ -
To Cost Next
B 3 -
C 4 -
D 5 C
E 9 C,D
Example

15. InitialtableofB UpdatetableofB
To Cost Next
A 3 -
C ∞ -
D 5 -
E 9 -
To Cost Next
A 3 -
C 6 D
D 5 -
E 9 -

16. Advantage & Disadvantage of Link-State Routing

18. Advantage & Disadvantage of DistanceVector Routing

19. • www.google.com
• wikipedia.org
• www.cisco.com
Reference

21. Thank You