Domain name server, Routing protocols – NETGEAR ME103 User Manual

Page 91

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Reference Manual for the ME103 802.11b ProSafe Wireless Access Point

Network, Routing, Firewall, and Cabling Basics

C-9

August 2003

The ME103 Access Point 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.

Domain Name Server

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.

Routing Protocols

Two protocols routers use extensively are:

Routing Information Protocol (RIP)

Address Resolution Protocol (ARP)

These two protocols are introduced below.

RIP

One of the protocols used by a router to build and maintain a picture of the network is RIP. Using
RIP, routers periodically update one another and check for changes to add to the routing table.

The ME103 Access Point supports both the older RIP-1 and the newer RIP-2 protocols. Among
other improvements, RIP-2 supports subnet and multicast protocols. RIP is not required for most
home applications.

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