Interlogix NS3562-8P-2S, Руководство пользователя

Страница: 232 / 245

230 NS3562-8P-2S User Manual
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 Continuity Check. This is a MEP functionality that is able to
detect loss of continuity in a network by transmitting CCM
frames to a peer MEP.
CCM Continuity Check Message. This is an OAM frame transmitted
from a MEP to its peer MEP and used to implement CC
functionality.
CDP Cisco Discovery Protocol
D
DEI Drop Eligible Indicator. It is a 1-bit field in the VLAN tag.
DES 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 Dynamic Host Configuration Protocol. It is a protocol used for
assigning dynamic IP addresses to devices on a network.
DHCP is 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.