User's Manual

User’s Manual of SGS-5240 Series Managed Switch
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Aggregation
Using multiple ports in parallel to increase the link speed beyond the limits of a port and to increase the
redundancy for higher availability.
(Also Port Aggregation, Link Aggregation).
ARP
ARP is an acronym for Address Resolution Protocol. It is a protocol that used to convert an IP address into a physical
address, such as an Ethernet address. ARP allows a host to communicate with other hosts when only the Internet
address of its neighbors is known. Before using IP, the host sends a broadcast ARP request containing the Internet
address of the desired destination system.
ARP Inspection
ARP Inspection is a secure feature. Several types of attacks can be launched against a host or devices connected to
Layer 2 networks by "poisoning" the ARP caches. This feature is used to block such attacks. Only valid ARP requests
and responses can go through the switch device.
Auto-Negotiation
Auto-negotiation is the process where two different devices establish the mode of operation and the speed
settings that can be shared by those devices for a link.
C
CC
CC is an acronym for Continuity Check. It is a MEP functionality that is able to detect loss of continuity in a network
by transmitting CCM frames to a peer MEP.
CCM
CCM is an acronym for Continuity Check Message. It is a OAM frame transmitted from a MEP to its peer MEP and
used to implement CC functionality.
CDP
CDP is an acronym for Cisco Discovery Protocol.
D
DEI
DEI is an acronym for Drop Eligible Indicator. It is a 1-bit field in the VLAN tag.
DES
DES is an acronym for Data Encryption Standard. It provides a complete description of a mathematical algorithm for
encrypting (enciphering) and decrypting (deciphering) binary coded information.
Encrypting data converts it to an unintelligible form called cipher. Decrypting cipher converts the data back to its
original form called plaintext. The algorithm described in this standard specifies both enciphering and deciphering
operations which are based on a binary number called a key.
DHCP
DHCP is an acronym for Dynamic Host Configuration Protocol. It is a protocol used for assigning dynamic IP
addresses to devices on a network.
DHCP used by networked computers (clients) to obtain IP addresses and other parameters such as the default
gateway, subnet mask, and IP addresses of DNS servers from a DHCP server.
The DHCP server ensures that all IP addresses are unique, for example, no IP address is assigned to a second
client while the first client's assignment is valid (its lease has not expired). Therefore, IP address pool
management is done by the server and not by a human network administrator.
Dynamic addressing simplifies network administration because the software keeps track of IP addresses rather
than requiring an administrator to manage the task. This means that a new computer can be added to a network
without the hassle of manually assigning it a unique IP address.