User’s Manual of WGR-500-4P and WGR-500-4PV
95
Appendix D: Glossary
A
ARP
ARP is an acronym for
A
ddress
R
esolution
P
rotocol. 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.
D
Default Gateway (Router)
Every non-router IP device needs to configure a default gateway’s IP address. When the device sends
out an IP packet, if the destination is not on the same network, the device has to send the packet to its
default gateway, which will then send it out towards the destination.
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
DHCP Relay is used to forward and to transfer DHCP messages between the clients and the server
when they are not on the same subnet domain.