MULTICAST IP ROUTING E-Book

Ummed Singh

• Herausgeber: BookRix
• Kategorie: Wissenschaft und neue Technologien
• Sprache: Englisch
• Veröffentlichungsjahr: 2023

Beschreibung

Multicast routing is a technique used in computer networks to optimize the transmission of data from one sender to multiple recipients. Instead of sending separate copies of the data to each recipient individually, multicast routing allows the sender to transmit the data once, and the recipients who are interested in receiving it form a multicast group. This method is particularly beneficial in scenarios where one-to-many communication is required, such as in voice over IP (VOIP), video on demand (VOD), video conferencing, and IP television (IPTV) applications. For example, during a live video conference, the video stream from the sender is multicast to a specific multicast group. Computers, devices, and IP phones that belong to that multicast group can receive the video stream simultaneously. When you enable multicast routing on your Firebox, it functions as a local multicast router. It takes on the responsibility of forwarding multicast traffic from the source to the intended recipients within your network. By efficiently handling multicast transmissions, the Firebox helps ensure that the multicast data reaches the receivers without unnecessary duplication or delays.

Leseprobe

Ummed Singh

MULTICAST IP ROUTING

MULTICAST IP ROUTING- Part 1

BookRix GmbH & Co. KG81371 Munich

Table of Index

 Multicast IP Addresses OverviewMapping Multicast IP Addresses to MAC AddressesMapping Multicast IP to MAC:IGMP Version 1IGMP Version 2IGMP Version 3IGMP FilterMulticast IGMP ProxyUnidirectional Satellite LinkRegular Internet Connection

This eBook is based on multicast ip routing that has been collected from different sources. For more information about this. Kindly write to [email protected]. I will happy to help you.

This eBook is a guide and serves as a first guide. In addition, please get expert advice or you can write to [email protected] for any query, we will be happy to help you. This book has been written on the advice of many experts and sources who have good command over routing and switching. They are listed at the end of this book.

                                          Copyright 2023 by Ummed SinghThis ebook is a guide and serves as a first guide. In addition, please get expert advice by writing an email to [email protected]. All images used in this book are taken from Lab created by author. All rights reserved, including the right to reproduce this book or portions thereof in any form whatsoever. For any query reach out to the author through email.

Multicast IP Addresses Overview

Multicast IP addresses differ from unicast IP addresses in that they represent a group of receivers rather than a single network device. The Internet Assigned Numbers Authority (IANA) has reserved the class D range (224.0.0.0 through 239.255.255.255) specifically for multicast purposes.

Within this range, certain addresses are reserved for specific uses and cannot be utilized for custom applications. For example, the range 224.0.0.0 - 224.0.0.255 is reserved by IANA for network protocols. Multicast IP packets within this range are not forwarded by routers between subnets. Here is an overview of some of the reserved link-local multicast addresses, many of which you may recognize:

224.0.0.1: All Hosts

224.0.0.2: All Multicast Routers

224.0.0.3: Unassigned

224.0.0.4: DVMRP Routers

224.0.0.5: OSPF Routers

224.0.0.6: OSPF DR/BDR Router

224.0.0.7: ST Routers

224.0.0.8: ST Hosts

224.0.0.9: RIPv2 Routers

224.0.0.10: EIGRP Routers

224.0.0.11: Mobile Agents

224.0.0.12: DHCP Server / Relay

224.0.0.13: All PIM Routers

224.0.0.14: RSVP Encapsulation

224.0.0.15: All CBT Routers

224.0.0.16: Designated SBM

224.0.0.17: All SBMS

224.0.0.18: VRRP

224.0.0.19 - 255: Unassigned

Additionally, the 224.0.1.0/24 range has been reserved by IANA for certain applications. Unlike the 224.0.0.0/24 range, addresses within the 224.0.1.0/24 range can be routed. Here is an overview of some addresses in this range:

224.0.1.0: VMTP Managers Group

224.0.1.1: NTP

224.0.1.2: SGI-Dogfight

224.0.1.3: Rwhod

224.0.1.6: NSS

224.0.1.8: SUN NIS+

224.0.1.20: Any Private Experiment

224.0.1.21: DVMRP on MOSPF

224.0.1.32: Mtrace

224.0.1.33: RSVP-encap-1

224.0.1.34: RSVP-encap-2

224.0.1.39: Cisco-RP-Announce

224.0.1.40: Cisco-RP-Discovery

224.0.1.52: Mbone-VCR-Directory

224.0.1.78: Tibco Multicast 1

224.0.1.79: Tibco Multicast 2

224.0.1.80 - 224.0.1.255: Unassigned

To ensure compliance, avoid using the 224.0.0.0/24 and 224.0.1.0/24 ranges. Instead, for multicast on local networks, you can safely

utilize the 239.0.0.0/8 range, which includes all addresses from 239.0.0.0 to 239.255.255.255.

Mapping Multicast IP Addresses to MAC Addresses

In order to establish communication between multicast IP addresses and MAC addresses at Layer 2, specific procedures are followed. Let's explore an example of a MAC address:

MAC Broadcast Multicast Bit:

The MAC address example above illustrates the structure. The first octet of the MAC address designates a bit reserved for broadcast or multicast traffic. When dealing with unicast traffic, this bit is set to 0. However, for broadcast or multicast traffic, it is set to 1.

At Layer 3, the Internet Assigned Numbers Authority (IANA) has allocated the range of class D addresses (224.0.0.0 – 239.255.255.255) specifically for multicast IP addresses. But what about Layer 2? Which MAC addresses are used for multicast traffic?

At Layer 2, a reserved prefix is also used for multicast traffic. The 24-bit MAC address prefix 01-00-5E is exclusively designated for Layer 2 multicast. Unfortunately, only half of this 24-bit prefix can be utilized for multicast, leaving us with only 23 bits of MAC address space for multicast purposes. Here's a visual representation:

Illustration of Multicast MAC Address (23-bit):