User`s guide

LAN-Cell 2 User’s Guide
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CHAPTER 14
DNS Screens
14.1 Overview
DNS (Domain Name System) is for mapping a domain name to its corresponding IP address
and vice versa. The DNS server is extremely important because without it, you must know the
IP address of a machine before you can access it. The LAN-Cell uses a system DNS server (in
the order you specify in the DNS System screen) to resolve domain names, for example, VPN,
DDNS and the time server.
14.1.1 What You Can Do in the DNS Screens
• Use the System screen (Section 14.2 on page 309) to configure the LAN-Cell to use a
DNS server to resolve domain names for LAN-Cell system features like VPN, DDNS and
the time server.
• Use the Add Address Record screen (Section 14.2.1 on page 311) to add an address
record.
• Use the Insert Name Server Record screen (Section 14.2.2 on page 312) to insert a name
server record.
• Use the Cache screen (Section 14.3 on page 313) to configure the LAN-Cell’s DNS
caching settings.
• Use the DHCP screen (Section 14.5 on page 315) to configure the DNS server information
that the LAN-Cell sends to its LAN, DMZ or WLAN DHCP clients.
• Use the DDNS screen (Section on page 309) to change your LAN-Cell’s DDNS
(Dynamic DNS) settings.
14.1.2 What You Need To Know About DNS
DNS Server Address Assignment
The LAN-Cell can get the DNS server addresses in the following ways.
1 The ISP tells you the DNS server addresses, usually in the form of an information sheet,
when you sign up. If your ISP gives you DNS server addresses, manually enter them in
the DNS server fields.
2 If your ISP dynamically assigns the DNS server IP addresses (along with the LAN-
Cell’s WAN IP address), set the DNS server fields to get the DNS server address from
the ISP.
3 You can manually enter the IP addresses of other DNS servers. These servers can be
public or private. A DNS server could even be behind a remote IPSec router (see Section
on page 308).