Presentation is loading. Please wait.

Presentation is loading. Please wait.

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Chapter 21 Unicast and Multicast Routing: Routing Protocols.

Similar presentations


Presentation on theme: "McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Chapter 21 Unicast and Multicast Routing: Routing Protocols."— Presentation transcript:

1 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Chapter 21 Unicast and Multicast Routing: Routing Protocols

2 McGraw-Hill©The McGraw-Hill Companies, Inc., Unicast Routing Metric Interior and Exterior Routing

3 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 21.1 Unicasting

4 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 In unicast routing, the router forwards the received packet through only one of its ports. Note:

5 McGraw-Hill©The McGraw-Hill Companies, Inc., Unicast Routing Protocols RIP OSPF BGP

6 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 21.2 Popular routing protocols

7 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 21.3 Autonomous systems

8 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Table 21.1 A distance vector routing table Destination Hop Count Next Router Other information

9 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Receive: a response RIP message 1. Add one hop to the hop count for each advertised destination. 2. Repeat the following steps for each advertised destination: 1. If (destination not in the routing table) 1. Add the advertised information to the table. 2. Else 1. If (next-hop field is the same) 1. Replace entry in the table with the advertised one. 2. Else 1. If (advertised hop count smaller than one in the table) 1. Replace entry in the routing table. 3. Return. RIP Updating Algorithm

10 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 21.4 Example of updating a routing table

11 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 21.5 Initial routing tables in a small autonomous system

12 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 21.6 Final routing tables for Figure 21.5

13 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 21.7 Areas in an autonomous system

14 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 21.8 Types of links

15 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 21.9 Point-to-point link

16 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Transient link

17 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Stub link

18 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Example of an internet

19 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Graphical representation of an internet

20 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Types of LSAs

21 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Router link

22 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Network link

23 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Summary link to network

24 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Summary link to AS boundary router

25 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure External link

26 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 In OSPF, all routers have the same link state database. Note:

27 McGraw-Hill©The McGraw-Hill Companies, Inc., Start with the local node (router): the root of the tree. 2. Assign a cost of 0 to this node and make it the first permanent node. 3. Examine each neighbor node of the node that was the last permanent node. 4. Assign a cumulative cost to each node and make it tentative. 5. Among the list of tentative nodes 1. Find the node with the smallest cumulative cost and make it permanent. 2. If a node can be reached from more than one direction 1. Select the direction with the shortest cumulative cost. 6. Repeat steps 3 to 5 until every node becomes permanent. Dijkstra Algorithm

28 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Shortest-path calculation

29 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Table 21.2 Link state routing table for router A NetworkCostNext RouterOther Information N15C N2 7D N310B N411D N515C

30 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Table 21.3 Path vector routing table NetworkNext RouterPath N01R01AS14, AS23, AS67 N02R05AS22, AS67, AS05, AS89 N03R06AS67, AS89, AS09, AS34 N04R12AS62, AS02, AS09

31 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Path vector messages

32 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Types of BGP messages

33 McGraw-Hill©The McGraw-Hill Companies, Inc., Multicast Routing IGMP Multicast Trees MBONE

34 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Multicasting

35 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 In multicast routing, the router may forward the received packet through several of its ports. Note:

36 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 IGMP is a group management protocol. It helps a multicast router create and update a list of loyal members related to each router interface. Note:

37 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure IGMP message types

38 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure IGMP message format

39 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Table 21.4 IGMP type field TypeValue General or special query0x11 or Membership report0x16 or Leave report0x17 or

40 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure IGMP operation

41 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Membership report

42 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 In IGMP, a membership report is sent twice, one after the other. Note:

43 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Leave report No Response

44 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 The general query message does not define a particular group. Note:

45 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure General query message No Response

46 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Example 1 Imagine there are three hosts in a network, as shown in Figure (below). A query message was received at time 0; the random delay time (in tenths of seconds) for each group is shown next to the group address. Show the sequence of report messages.

47 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Solution The events occur in this sequence: 1.Time 12. The timer for in host A expires and a membership report is sent, which is received by the router and every host including host B which cancels its timer for Time 30. The timer for in host A expires and a membership report is sent, which is received by the router and every host including host C which cancels its timer for Time 50. The timer for in host B expires and a membership report is sent, which is received by the router and every host. 4.Time 70. The timer for in host C expires and a membership report is sent, which is received by the router and every host including host A which cancels its timer for

48 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 In a source-based tree approach, the combination of source and group determines the tree. Note:

49 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 In the group-shared tree approach, the group determines the tree. Note:

50 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Logical tunneling

51 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure MBONE

52 McGraw-Hill©The McGraw-Hill Companies, Inc., Multicast Routing Protocols DVMRP MOSPF CBT PIM

53 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Multicast routing protocols

54 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Reverse path forwarding

55 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 In reverse path forwarding, the router forwards only the packets that have traveled the shortest path from the source to the router; all other copies are discarded. RPF prevents the formation of loops. Note:

56 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure RPF versus RPB

57 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 RPB creates a shortest-path broadcast tree from the source to each destination. It guarantees that each destination receives one and only one copy of the packet. Note:

58 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure RPF, RPB, and RPM

59 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 RPM adds pruning and grafting to RPB to create a multicast shortest- path tree that supports dynamic membership changes. Note:

60 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure RPF versus RPB

61 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Unicast tree and multicast tree

62 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Shared-group tree with rendezvous router

63 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Sending a multicast packet to the rendezvous router

64 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 In CBT, the source sends the multicast packet to the core router. The core router decapsulates the packet and forwards it to all interested hosts. Note:

65 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 PIM-DM uses RPF and pruning and grafting strategies to handle multicasting. However, it is independent of the underlying unicast protocol. Note:

66 McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 PIM-SM is similar to CBT but uses a simpler procedure. Note:


Download ppt "McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Chapter 21 Unicast and Multicast Routing: Routing Protocols."

Similar presentations


Ads by Google