Инструкция для ZYXEL ZyWALL 2WG EE

(скачивание инструкции бесплатно)

Формат файла: PDF

Доступность: Бесплатно как и все руководства на сайте. Без регистрации и SMS.

Дополнительно: Чтение инструкции онлайн

Chapter 22 DNS Screens

ZyWALL 2WG User’s Guide

427

The following table describes the labels in this screen.

22.3 The DNS Cache Screen

DNS cache is the temporary storage area where a router stores responses from DNS servers.
When the ZyWALL receives a positive or negative response for a DNS query, it records the
response in the DNS cache. A positive response means that the ZyWALL received the IP
address for a domain name that it checked with a DNS server within the five second DNS
timeout period. A negative response means that the ZyWALL did not receive a response for a
query it sent to a DNS server within the five second DNS timeout period.
When the ZyWALL receives DNS queries, it compares them against the DNS cache before
querying a DNS server. If the DNS query matches a positive entry, the ZyWALL responses
with the IP address from the entry. If the DNS query matches a negative entry, the ZyWALL
replies that the DNS query failed.
To configure your ZyWALL’s DNS caching, click

ADVANCED

DNS

Cache

. The screen

appears as shown.

Table 136

ADVANCED > DNS > Insert (Name Server Record)

LABEL

DESCRIPTION

Domain Zone

This field is optional.
A domain zone is a fully qualified domain name without the host. For example,

zyxel.com.tw is the domain zone for the www.zyxel.com.tw fully qualified domain

name. For example, whenever the ZyWALL receives needs to resolve a

zyxel.com.tw domain name, it can send a query to the recorded name server IP

address.
Leave this field blank if all domain zones are served by the specified DNS server(s).

DNS Server

Select the

DNS Server(s) from ISP

radio button if your ISP dynamically assigns

DNS server information. You also need to select an interface through which the ISP

provides the DNS server IP address(es). The interface should be activated and set

as a DHCP client.The fields below display the (read-only) DNS server IP

address(es) that the ISP assigns.

N/A

displays for any DNS server IP address fields

for which the ISP does not assign an IP address.

N/A

displays for all of the DNS

server IP address fields if the ZyWALL has a fixed WAN IP address.
Select

Public DNS Server

if you have the IP address of a DNS server. The IP

address must be public or a private address on your local LAN. Enter the DNS

server's IP address in the field to the right.

Public DNS Server

entries with the IP address set to 0.0.0.0 are not allowed.

Select

Private DNS Server

if the DNS server has a private IP address and is located

behind a VPN peer. Enter the DNS server's IP address in the field to the right.
With a private DNS server, you must also configure the first DNS server entry for the

LAN, DMZ and/or WLAN in the

DNS DHCP

screen to use

DNS Relay

You must also configure a VPN rule since the ZyWALL uses a VPN tunnel when it

relays DNS queries to the private DNS server. The rule must include the LAN IP

address of the ZyWALL as a local IP address and the IP address of the DNS server

as a remote IP address.

Private DNS Server

entries with the IP address set to 0.0.0.0 are not allowed.

Apply

Click