Download presentation

Presentation is loading. Please wait.

Published byRobert Short Modified over 3 years ago

1
**Contents Routing Protocol and Algorithm Classifications**

Link State Routing Algorithm Distance Vector Routing Algorithm LS Algorithm vs. DV Algorithm Hierarchical Routing

2
**Routing Protocol and Algorithm**

Determining the path(route) destination router first-hop router default router destination host 5 2 1 3 B A C E D F source host least-cost path source router

3
**Classifications Global vs. decentralized Static vs. dynamic**

global(link state algorithm) : complete information about connectivity and link costs Static vs. dynamic static : routes change very slowly Load-sensitive vs. load-insensitive load-sensitive : link costs reflect congestion Typical used Dynamic link state routing algorithm Dynamic distance vector routing algorithm

4
**Link State Routing Algorithm**

Each node broadcasts the identities and costs to its directly attached neighbors Dijkstra’s algorithm

5
**Link State Routing Algorithm**

Oscillation(page 307) D B C A e 1 1+e 1 2+e 1 e 1+e 2+e 1+e 1 2+e 1+e 1

6
**Distance Vector Routing Algorithm**

Iterative, asynchronous, distributed Distance table DX(Y,Z) : cost of the direct link from X to Z + Z’s currently known minmum-cost path to Y DX(Y,Z)=c(X,Z)+minw{Dz(Y,w)}

7
**Distance Vector Routing Algorithm**

Initialization: DX(*,v) = inifinite, DX(v,v)=c(x,v) Send minwDX(y,w) to each neighbor when they changes C(X,V) changes Neighbor node send its update

8
**Distance Vector Routing Algorithm**

DY X Z 2 ∞ 1 Y 2 1 X Z 7 Dz X Y 7 ∞ 1 DX Y Z 2 ∞ 7

9
**Distance Vector Routing Algorithm**

DY X Z 2 8 9 1 Y 2 1 X Z 7 Dz X Y 7 3 9 1 DX Y Z 2 8 3 7

10
**Distance Vector Routing Algorithm**

DY X Z 2 4 5 1 Y 2 1 X Z 7 Dz X Y 7 3 9 1 DX Y Z 2 8 3 7

11
**Distance Vector Routing Algorithm**

Decrease DY X Z 4 6 Y 1 4 1 X Z 50 Dz X Y 50 5

12
**Distance Vector Routing Algorithm**

Decrease DY X Z 1 6 Y 1 4 1 X Z 50 Dz X Y 50 5

13
**Distance Vector Routing Algorithm**

Decrease DY X Z 1 6 Y 1 4 1 X Z 50 Dz X Y 50 2

14
**Distance Vector Routing Algorithm**

Decrease DY X Z 1 6 Y 1 4 1 X Z 50 Dz X Y 50 2

15
**Distance Vector Routing Algorithm**

Increase DY X Z 4 6 Y 60 4 1 X Z 50 Dz X Y 50 5

16
**Distance Vector Routing Algorithm**

Increase DY X Z 60 6 Y 60 4 1 Routing loop X Z 50 Dz X Y 50 5

17
**Distance Vector Routing Algorithm**

Increase DY X Z 60 6 Y 60 4 1 X Z 50 Dz X Y 50 7

18
**Distance Vector Routing Algorithm**

Increase DY X Z 60 8 Y 60 4 1 X Z 50 Dz X Y 50 7

19
**Distance Vector Routing Algorithm**

Increase DY X Z 60 8 Y 60 4 1 Too many iterations! (count-to-infinity problem) X Z 50 Dz X Y 50 9

20
**Distance Vector Routing Algorithm**

Poisoned reverse DY X Z 4 ∞ Y 60 4 1 X Z 50 Dz X Y 50 5

21
**Distance Vector Routing Algorithm**

Poisoned reverse DY X Z 60 ∞ Y 60 4 1 X Z 50 Dz X Y 50 5

22
**Distance Vector Routing Algorithm**

Poisoned reverse DY X Z 60 ∞ Y 60 4 1 X Z 50 Dz X Y 50 61

23
**Distance Vector Routing Algorithm**

Poisoned reverse DY X Z 60 51 Y 60 4 1 X Z 50 Dz X Y 50 61

24
**Distance Vector Routing Algorithm**

Poisoned reverse Cannot solve general count-to-infinity problem DY X Z 60 51 Y 60 4 1 X Z 50 Dz X Y 50 ∞

25
**LS Algorithm vs. DV Algorithm**

Message complexity O(nE) Maybe small Speed of convergence O(n2) algorithm Slow(count-to-infinity problem) Robustness Good Bad

26
**Hierarchical Routing View network as interconnected routers**

Scale Administrative autonomy Organize routers into autonomy systems(AS)

27
**Hierarchical Routing B.a A.a A.b A.c A.d C.b C.c C.a Host H1 Host H2**

Autonomy system(AS) Gateway router Intra-AS Inter-AS

28
**Topological view for inter-AS routing protocol**

Hierarchical Routing B.a C.a A.a A.c Topological view for inter-AS routing protocol

29
END

Similar presentations

OK

4-1 Network layer r transport segment from sending to receiving host r on sending side encapsulates segments into datagrams r on rcving side, delivers.

4-1 Network layer r transport segment from sending to receiving host r on sending side encapsulates segments into datagrams r on rcving side, delivers.

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on ram and rom difference 7 qc tools best ppt on surface Ppt on metro rail project Ppt on electricity for class 10 download Ppt on spiritual leadership inc Ppt on finite difference method Ppt on notepad editor in java Ppt on instrument landing system history Free download ppt on ms access 2007 Ppt on school annual function