ZyXEL P-791R v2 Guia Do Utilizador

P-791R v2 Support Notes

Time service is implemented by the Daytime protocol (RFC-867), Time
protocol (RFC-868), and NTP protocol(RFC-1305). You have to assign an IP
address of a time server and then, the P-791R v2will get the date, time, and
time-zone information from this server. You can configure it in Web
Configurator, Advanced Setup, Maintenance -> System -> Time Setting.

15. Using IP Multicast

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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-791R v2 queries all directly
connected networks to gather group membership.