Oce cm3530 Network Administrator's Manual - page 178

178

Network Administrator’s Guide — Setting up DNS and Mail Servers

Setting up DNS and Mail Servers

This section describes how to set up the DNS server and Mail server for the Internet connection.

The figure illustrates a general network environment for Internet connection from a local area

network.

As shown in the figure above, a local area network usually consists of several segments: one

connects to the router directly (and is assigned a Global IP address) and others are for client

computers.

To enable Internet access from the local area network, the router must be assigned a Global IP

Address.  In the above figure, the Private IP addresses have been assigned to all devices in the

local area network, and the router maps between the Private IP addresses and Global IP

Addresses using the NAT, Network Address Translation. This gives clients and servers access to

the Internet through the router.

Regarding the security, it is preferred to place this equipment in a different segment from the

router that connects to the Internet.

Also, in order to enable Internet communication from the device in the local area network, the

Domain Name Service is used.  In the Internet, the DNS server specifies the domain name

related to the global IP address of the servers.  To recognize the domain names in the Internet,

the domain names must be registered in both the DNS server in the Internet, which is managed

by the public DNS organization, and the DNS server in the local area network where the remote

devices are actually located.  To configure the DNS server in your local area network, create fol-

lowing records in the DNS server:

•

DNS zone name (i.e. “ifax.com”)

Client

Client

DNS Server

Email Server

Router

Internet

LAN

192.168.0.2

192.168.0.3

Proxy Server

192.168.0.3

192.168.0.4

192.168.1.1

192.168.1.2

192.168.1.3

192.168.1.4

192.168.0.1

Global IP Address

Router