Productos de la Marca ZyXEL

P-660HN Series Support Notes

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protocol(RFC-868), and NTP protocol(RFC-1305). You have to assign an IP

address of a time server and then, the P-660HN-T1A will get the date, time,

and time-zone information from this server. You can configure it in Web

Configurator, Advanced Setup, Maintenance -> System -> Time Setting.

13. 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 P-660HN-T1A queries all directly

connected networks to gather group membership.

After that, the P-660HN-T1A updates the information by periodic queries. The

P-660HN-T1A implementation of IGMP is also compatible with version 1. The

multicast setting can be turned on or off on Ethernet and remote nodes.