HP 5500 Ei 5500 Si Switch Series Configuration Guide

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Multicast models 
Based on how the receivers treat the multicast sources, the multicast models include any-source multicast 
(ASM), source-filtered multicast (SFM), and source-specific multicast (SSM). 
ASM model 
In the ASM model, any sender can send information to a multicast group as a multicast source, and 
receivers can join a multicast group (identified by a group address) and obtain multicast information 
addressed to that multicast group. In this model, receivers do not know the positions of...

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Multicast addresses 
Network-layer multicast addresses (multicast IP addresses) enables communication between multicast 
sources and multicast group members. In addition, a technique must be available to map multicast IP 
addresses to link-layer multicast MAC addresses.  
IP multicast addresses 
•  IPv4 multicast addresses 
Internet Assigned Numbers Authority (IANA) a ssigned the Class D address space (224.0.0.0 to 
239.255.255.255) to IPv4 multicast.  
Table 2  Class D IP address blocks and...

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Address Description 
224.0.0.12  Dynamic Host Configuration Protocol (DHCP) server/relay agent
 
224.0.0.13  All Protocol Independent Multicast (PIM) routers 
224.0.0.14  Resource Reservation Protocol (RSVP) encapsulation  
224.0.0.15  All Core-Based Tree (CBT) routers 
224.0.0.16  Designated Subnetwork Bandwidth Management (SBM)  
224.0.0.17 All SBMs 
224.0.0.18  Virtual Router Redundancy Protocol (VRRP) 
 
•  IPv6 multicast addresses 
Figure 4  IPv6 multicast format  
 
 
The following describes the...

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{ Scope —The Scope field contains four bits, which indicate the scope of the IPv6 internetwork for 
which the multicast traffic is intended.  
Table 5  Values of the Scope field 
Value Meanin
g  
0, F  Reserved 
1 Interface-local  scope 
2 Link-local scope 
3 Subnet-local  scope 
4 Admin-local scope 
5 Site-local scope  
6, 7, 9 through D Unassigned 
8 Organization-local  scope 
E Global scope 
 
{ 
Group ID —The Group ID field contains 1 12  b i t s .  I t  u n i q u e l y  i d e n t i fi e s  a n  I...

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Figure 7 An example of IPv6-to-MAC address mapping 
 
 
Multicast protocols 
Generally, Layer 3 multicast refers to IP multicast working at the network layer. The corresponding 
multicast protocols are Layer 3 multicast protocols, which include IGMP, MLD, PIM, IPv6 PIM, MSDP, 
MBGP, and IPv6 MBGP. Layer 2 multicast refers to IP multicast working at the data link layer. The 
corresponding multicast protocols are Layer 2 multicast protocols, which include IGMP snooping, MLD 
snooping, PIM snooping, IPv6...

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protocols define the mechanism of establishing and maintaining group memberships between 
hosts and Layer 3 multicast devices.  
•   Multicast routing protocols 
A multicast routing protocol runs on Layer 3 mult icast devices to establish and maintain multicast 
routes and forward multicast packets correctly and ef ficiently. Multicast routes constitute loop-free 
data transmission paths from a data source to mult iple receivers, namely, a multicast distribution 
tree. 
In the ASM model, multicast...

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•  PIM snooping and IPv6 PIM snooping 
PIM snooping and IPv6 PIM snooping run on Laye r 2 devices. They determine which ports are 
interested in multicast data by analyzing the re ceived IPv6 PIM messages, and add the ports to a 
multicast forwarding entry to make  sure that multicast data can be forwarded to only the ports that 
are interested in the data.  
•   Multicast VLAN and IPv6 multicast VLAN 
In the traditional multicast-on-demand mode, when  users in different VLANs on a Layer 2 device...

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Figure 10 VPN networking diagram  
 
 
•  The provider (P) device belongs to the public netw ork. The customer edge (CE) devices belong to 
their respective VPNs. Each CE device serves its own VPN and maintains only one set of forwarding 
mechanisms.  
•   The provider edge (PE) devices connect to the public network and the VPNs at the same time. Each 
PE device must strictly distinguish the information for different networks, and maintain a separate 
forwarding mechanism for each network. On a PE...

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Configuring IGMP snooping 
Overview 
Internet Group Management Protocol (IGMP) snooping  is a multicast constraining mechanism that runs 
on Layer 2 devices to manage and control multicast groups. 
By analyzing received IGMP messages, a Layer 2 devi ce that runs IGMP snooping establishes mappings 
between ports and multicast MAC addresses, and forwards multicast data based on these mappings.  
As shown in  Figure 11,
 when IGMP snooping does not run on  the Layer 2 switch, multicast packets are 
fl...

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Figure 12  IGMP snooping related ports  
 
 
Ports involved in IGMP snooping, as shown in Figure 12, ar e described as follows:  
•   Router port —A router port is a port on an Ethernet switch that leads the switch toward a Layer 3 
multicast device (designated router or IGMP querier). In the figure, GigabitEthernet 1/0/1 of 
Switch A and GigabitEthernet 1/0/1 of Switch B are  router ports. The switch registers all its local 
router ports in its  router port list.  
In this document, a router port...