Planet GS-5220 Series, User Manual, Page: 548 / 568

User’s Manual of GS-5220 LCD Series
548
CDP is an acronym for C isco D iscovery P rotocol.
D
DEI
DEI is an acronym for D rop E ligible I ndicator. It is a 1-bit field in the VLAN tag.
DES
DES is an acronym for D ata E ncryption S tandard. 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 D ynamic H ost C onfiguration P rotocol. 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.
DHCP Relay