Netgear CG814WG 사용자 설명서

Networks, Routing, and Firewall Basics

D-9

If a device sends data to another station on the network and the destination MAC address is not yet 
recorded, ARP is used. An ARP request is broadcast onto the network. All stations on the network 
receive and read the request. The destination IP address for the chosen station is included as part of 
the message so that only the station with this IP address responds to the ARP request. All other 
stations discard the request. 

The station with the correct IP address responds with its own MAC address directly to the sending 
device. The receiving station provides the transmitting station with the required destination MAC 
address. The IP address data and MAC address data for each station are held in an ARP table. The 
next time data is sent, the address can be obtained from the address information in the table.

For more information about address assignment, refer to the IETF documents RFC 1597, Address 
Allocation for Private Internets, and RFC 1466, Guidelines for Management of IP Address Space.

For more information about IP address translation, refer to RFC 1631, The IP Network Address 
Translator (NAT).

Many of the resources on the Internet can be addressed by simple descriptive names such as 
www.NETGEAR.com. This addressing is very helpful at the application level, but the descriptive 
name must be translated to an IP address in order for a user to actually contact the resource. Just as 
a telephone directory maps names to phone numbers, or as an ARP table maps IP addresses to 
MAC addresses, a domain name system (DNS) server maps descriptive names of network 
resources to IP addresses.

When a PC accesses a resource by its descriptive name, it first contacts a DNS server to obtain the 
IP address of the resource. The PC sends the desired message using the IP address. Many large 
organizations, such as ISPs, maintain their own DNS servers and allow their customers to use the 
servers to look up addresses.