Netgear FVS328 참조 매뉴얼

C-10

Networks, Routing, and Firewall Basics

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.

When an IP-based local area network is installed, each PC must be configured with an IP address. 
If the computers need to access the Internet, they should also be configured with a gateway address 
and one or more DNS server addresses. As an alternative to manual configuration, there is a 
method by which each PC on the network can automatically obtain this configuration information. 
A device on the network may act as a Dynamic Host Configuration Protocol (DHCP) server. The 
DHCP server stores a list or pool of IP addresses, along with other information (such as gateway 
and DNS addresses) that it may assign to the other devices on the network. The FVS328 Firewall 
has the capacity to act as a DHCP server.

The FVS328 Firewall also functions as a DHCP client when connecting to the ISP. The firewall 
can automatically obtain an IP address, subnet mask, DNS server addresses, and a gateway address 
if the ISP provides this information by DHCP.

When your LAN connects to the Internet through a router, an opportunity is created for outsiders 
to access or disrupt your network. A NAT router provides some protection because by the very 
nature of the Network Address Translation (NAT) process, the network behind the NAT router is 
shielded from access by outsiders on the Internet. However, there are methods by which a 
determined hacker can possibly obtain information about your network or at the least can disrupt 
your Internet access. A greater degree of protection is provided by a firewall router.