Pilz PSSnet SHL 8T MRP - Manual (Page 336)

Glossary
336
PSSnet SHL - Command Line Interface
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IGMP. See “Internet Group
Management Protocol” on page 336.
IGMP Snooping. A series of
operations performed by
intermediate systems to add logic to
the network to optimize the flow of
multicast traffic; these intermediate
systems (such as Layer 2 switches)
listen for IGMP messages and build
mapping tables and associated
forwarding filters, in addition to
reducing the IGMP protocol traffic.
See “Internet Group Management
Protocol” on page 336 for more
information.
Internet Control Message
Protocol. ICMP is an extension to
the Internet Protocol (IP) that
supports packets containing error,
control, and informational
messages. The PING command, for
example, uses ICMP to test an
Internet connection.
Internet Group Management
Protocol. IGMP is the standard for
IP Multicasting on the Internet.
IGMP is used to establish host
memberships in particular multicast
groups on a single network. The
mechanisms of the protocol allow a
host to inform its local router, using
Host Membership Reports, that it
wants to receive messages
addressed to a specific multicast
group. All hosts conforming to Level
2 of the IP Multicasting specification
require IGMP.
IP. See “Internet Protocol” on
page 336.
IP Multicasting. Sending out data
to distributed servers on the MBone
(Multicast Backbone). For large
amounts of data, IP Multicast is
more efficient than normal Internet
transmissions because the server
can broadcast a message to many
recipients simultaneously. Unlike
traditional Internet traffic that
requires separate connections for
each source-destination pair, IP
Multicasting allows many recipients
to share the same source. This
means that just one set of packets is
transmitted for all the destinations.
Internet Protocol. The method or
protocol by which data is sent from
one computer to another on the
Internet. Each computer (known as
a host) on the Internet has at least
one IP address that uniquely
identifies it among all other
computers on the Internet. When
you send or receive data (for
example, an e-mail note or a Web
page), the message gets divided
into little chunks called packets.
Each of these packets contains both
the sender's Internet address and
the receiver's address. Any packet is
sent first to a gateway computer that
understands a small part of the
Internet. The gateway computer
reads the destination address and
forwards the packet to an adjacent
gateway that in turn reads the
destination address and so forth
across the Internet until one