Chapter 12 Multicasting and Multicast Routing Protocols PDF

Chapter 12 Multicasting And Multicast Routing Protocols TCP/IP Protocol Suite 1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction...

Chapter 12 Multicasting And Multicast Routing Protocols TCP/IP Protocol Suite 1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or  Figure 12.4 Mapping class D to Ethernet physical address TCP/IP Protocol Suite 2  Note An Ethernet multicast physical address is in the range 01:00:5E:00:00:00 to 01:00:5E:7F:FF:FF. TCP/IP Protocol Suite 3 Example 12.2 Change the multicast IP address 232.43.14.7 to an Ethernet multicast physical address. Solution We can do this in two steps: a. We write the rightmost 23 bits of the IP address in hexadecimal. This can be done by changing the rightmost 3 bytes to hexadecimal and then subtracting 8 from the leftmost digit if it is greater than or equal to 8. In our example the result is 2B:0E:07. b. We add the result of part a to the starting Ethernet multicast address, which is 01:00:5E:00:00:00. The result is TCP/IP Protocol Suite 4 Example 12.3 Change the multicast IP address 238.212.24.9 to an Ethernet multicast address. Solution We can do this in two steps: a. The rightmost 3 bytes in hexadecimal are D4:18:09. We need to subtract 8 from the leftmost digit, resulting in 54:18:09. b. We add the result of part a to the Ethernet multicast starting address. The result is TCP/IP Protocol Suite 5  Figure 12.5 Tunneling TCP/IP Protocol Suite 6  12-3 IGMP Multicast communication means that a sender sends a message to a group of recipients that are members of the same group. Each multicast router needs to know the list of groups that have at least one loyal member related to each interface. Collection of this type of information is done at two levels: locally and globally. The first task is done by the IGMP protocol; the second task is done by the multicast routing protocols. TCP/IP Protocol Suite 7  Topics Discussed in the Section  Group Management  IGMP Messages  IGMP Protocol Applied to host  IGMP Protocol Applied to Router  Role of IGMP in Forwarding  Variables and Timers  Encapsulation  Compatibility with other Versions TCP/IP Protocol Suite 8  Figure 12.6 Position of IGMP in the network layer TCP/IP Protocol Suite 9  Note IGMP is a group management protocol. It helps a multicast router create and update a list of loyal members related to each router interface. TCP/IP Protocol Suite 10  Figure 12.7 IGMP messages TCP/IP Protocol Suite 11