D-Link DES-3226L, Cli Command Reference

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124 D-Link DES-3226L Command Line Reference
In some systems, the device's IP address can even change
while it is still connected. DHCP also supports a mix of
static and dynamic IP addresses. Dynamic addressing
simplifies network administration because the software
tracks IP addresses rather than requiring an administrator
to manage the task. A new computer can be added to a
network without the hassle of manually assigning it a
unique IP address.
E
EEPROM. See “Electronically Erasable Programmable
Read Only Memory” on page 124.
Electronically Erasable Programmable Read Only
Memory.
EEPROM is also known as Flash memory. This
is re-programmable memory.
F
FRU. The field replaceable unit number.
Fast STP. A high-performance Spanning Tree
Protocol.See “STP” on page 127 for more information.
FIFO. First In First Out.
Flash Memory. See “EEPROM” on page 124.
Flow Control. The process of adjusting the flow of data
from one network device to another to ensure that the
receiving device can handle all of the incoming data. This
is particularly important where the sending device is
capable of sending data much faster than the receiving
device can receive it. There are many flow control
mechanisms. One of the most common flow control
protocols for asynchronous communication is called xon-
xoff. In this case, the receiving device sends a an “xoff”
message to the sending device when its buffer is full. The
sending device then stops sending data. When the
receiving device is ready to receive more data, it sends an
“xon” signal.
Forwarding. When a frame is received on an input port
on a switch, the address is checked against the lookup
table. If the lookup table has recorded the destination
address, the frame is automatically forwarded on an output
port.
Frame Check Sequence. The extra characters added to a
frame for error detection and correction. FCS is used in
X.25, HDLC, Frame Relay, and other data link layer
protocols.
G
GE. See “Gigabit Ethernet” on page 124.
Gigabit Ethernet. A high-speed Ethernet connection.
H
hop count. The number of routers that a data packet
passes through on its way to its destination.
I
ICMP. See “Internet Control Message Protocol” on
page 124.
IGMP. See “Internet Group Management Protocol” on
page 124.
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 124 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 125.
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.