ZyXEL Communications P-2302R-P1C manual Using IP Multicast

P2302R-P1C Support Notes

Using IP Multicast

∙What is IP Multicast ?

Traditionally, IP packets are transmitted in two ways - unicast or broadcast. Multicast is a third way to deliver IP packets to a group of hosts. Host groups are identified by class D IP addresses, i.e., those with "1110" as their higher-order bits. In dotted decimal notation, host group addresses range from 224.0.0.0 to 239.255.255.255. Among them, 224.0.0.1 is assigned to the permanent IP hosts group, and 224.0.0.2 is assigned to the multicast routers group.

IGMP (Internet Group Management Protocol) is the protocol used to support multicast groups. The latest version is version 2 (see RFC2236). IP hosts use IGMP to report their multicast group membership to any immediate-neighbor multicast routers so the multicast routers can decide if a multicast packet needs to be forwarded. At start up, the ZyXEL Device queries all directly connected networks to gather group membership.

After that, the ZyXEL Device updates the information by periodic queries. The ZyXEL Device implementation of IGMP is also compatible with version 1. The multicast setting can be turned on or off on Ethernet and remote nodes.

∙IP Multicast Setup

Enable IGMP in ZyXEL Device's LAN in menu 3.2:

	Menu 3.2 - TCP/IP and DHCP Ethernet Setup
DHCP= Server		TCP/IP Setup:
Client IP	Pool:
Starting Address= 192.168.1.33		IP Address= 192.168.1.1
Size of	Client IP Pool= 32	IP Subnet Mask= 255.255.255.0
First DNS	Server= From ISP	RIP Direction= Both

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