Comtrol RocketLinx MP1204-XT, Руководство пользователя

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394 - Glossary RocketLinx MP1204-XT User Guide : 2000644 Rev. A
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ICMP
ICMP is an acronym for Internet Control Message Protocol. It is a protocol that generated the error response,
diagnostic or routing purposes. ICMP messages generally contain information about routing difficulties or
simple exchanges such as time-stamp or echo transactions. For example, the PING command uses ICMP to
test an Internet connection.
IEEE 802.1X
IEEE 802.1X is an IEEE standard for port-based Network Access Control. It provides authentication to
devices attached to a LAN port, establishing a point-to-point connection or preventing access from that port if
authentication fails. With 802.1X, access to all switch ports can be centrally controlled from a server, which
means that authorized users can use the same credentials for authentication from any point within the
network.
IGMP
IGMP is an acronym for Internet Group Management Protocol. It is a communications protocol used to
manage the membership of Internet Protocol multicast groups. IGMP is used by IP hosts and adjacent
multicast routers to establish multicast group memberships. It is an integral part of the IP multicast
specification, like ICMP for unicast connections. IGMP can be used for on-line video and gaming, and allows
more efficient use of resources when supporting these uses.
IGMP Querier
A router sends IGMP Query messages onto a particular link. This router is called the Querier. There will be
only one IGMP Querier that wins Querier election on a particular link.
IMAP
IMAP is an acronym for Internet Message Access Protocol. It is a protocol for email clients to retrieve email
messages from a mail server.
IMAP is the protocol that IMAP clients use to communicate with the servers, and SMTP is the protocol used
to transport mail to an IMAP server.
The current version of the Internet Message Access Protocol is IMAP4. It is similar to Post Office Protocol
version 3 (POP3), but offers additional and more complex features. For example, the IMAP4 protocol leaves
your email messages on the server rather than downloading them to your computer. If you wish to remove
your messages from the server, you must use your mail client to generate local folders, copy messages to your
local hard drive, and then delete and expunge the messages from the server.
IP
IP is an acronym for Internet Protocol. It is a protocol used for communicating data across an internet
network.
IP is a
best effort
system, which means that no packet of information sent over is assured to reach its
destination in the same condition it was sent. Each device connected to a Local Area Network (LAN) or Wide
Area Network (WAN) is given an Internet Protocol address, and this IP address is used to identify the device
uniquely among all other devices connected to the extended network.
The current version of the Internet protocol is IPv4, which has 32-bits Internet Protocol addresses allowing