AMG1202-T10B/AMG1302-T10B
Support Notes
61
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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
AMG1302-T10B/AMG1202-T10B will get the date, time, and time-zone
information from this server. You can configure it in Web Configurator,
Advanced Setup,
Maintenance -> Time
Setting.
11. 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 AMG1302-T10B/AMG1202-T10B
queries all directly connected networks to gather group membership.
After that, the AMG1302-T10B/AMG1202-T10B updates the information by
periodic queries. The AMG1302-T10B/AMG1202-T10B implementation of
IGMP is also compatible with version 1. The multicast setting can be turned on
or off on Ethernet and remote nodes.
AMG1302-T10B/AMG1202-T10B supports IGMP v1, v2 and IGMP v3 without
source filtering.