ZyWALL 35 User’s Guide
346
Chapter 21 DNS
The following table describes the labels in this screen.
21.9 Configuring
DNS LAN
Click
DNS
and then the
LAN
tab to open the
DNS LAN
screen shown next. Use this screen to
configure the DNS server information that the ZyWALL sends to its LAN DHCP clients.
Table 123
DNS Cache
LABEL
DESCRIPTION
DNS Cache Setup
Cache Positive DNS
Resolutions
Select the check box to record the positive DNS resolutions in the cache.
Caching positive DNS resolutions helps speed up the ZyWALL’s processing of
commonly queried domain names and reduces the amount of traffic that the
ZyWALL sends out to the WAN.
Maximum TTL
Type the maximum time to live (TTL) (60 to 3600 seconds). This sets how long
the ZyWALL is to allow a positive resolution entry to remain in the DNS cache
before discarding it.
Cache Negative
DNS Resolutions
Caching negative DNS resolutions helps speed up the ZyWALL’s processing of
commonly queried domain names (for which DNS resolution has failed) and
reduces the amount of traffic that the ZyWALL sends out to the WAN.
Negative Cache
Period
Type the time (60 to 3600 seconds) that the ZyWALL is to allow a negative
resolution entry to remain in the DNS cache before discarding it.
Apply
Click
Apply
to save your changes back to the ZyWALL.
Reset
Click
Reset
to begin configuring this screen afresh.
DNS Cache Entry
Flush
Click this button to clear the cache manually. After you flush the cache, the
ZyWALL must query the DNS servers again for any domain names that had
been previously resolved.
Refresh
Click this button to reload the cache.
#
This is the index number of a record.
Cache Type
This displays whether the response for the DNS request is positive or negative.
Domain Name
This is the domain name of a host.
IP Address
This is the (resolved) IP address of a host. This field displays
0.0.0.0
for
negative DNS resolution entries.
Remaining Time
(sec)
This is the number of seconds left before the DNS resolution entry is discarded
from the cache.
Modify
Click the delete icon to remove the DNS resolution entry from the cache.
Summary of Contents for ZyXEL ZyWALL 35
Page 1: ...ZyWALL 35 Internet Security Appliance User s Guide Version 3 64 3 2005 ...
Page 2: ......
Page 38: ...ZyWALL 35 User s Guide 36 ...
Page 46: ...ZyWALL 35 User s Guide 44 ...
Page 74: ...ZyWALL 35 User s Guide 72 Chapter 2 Introducing the Web Configurator ...
Page 90: ...ZyWALL 35 User s Guide 88 Chapter 3 Wizard Setup ...
Page 100: ...ZyWALL 35 User s Guide 98 Chapter 4 LAN Screens ...
Page 106: ...ZyWALL 35 User s Guide 104 Chapter 5 Bridge Screens ...
Page 128: ...ZyWALL 35 User s Guide 126 Chapter 6 Wireless LAN ...
Page 135: ...ZyWALL 35 User s Guide Chapter 7 WAN Screens 133 Figure 47 General ...
Page 152: ...ZyWALL 35 User s Guide 150 Chapter 7 WAN Screens Figure 57 Dial Backup Setup ...
Page 158: ...ZyWALL 35 User s Guide 156 Chapter 7 WAN Screens ...
Page 166: ...ZyWALL 35 User s Guide 164 Chapter 8 DMZ Screens ...
Page 234: ...ZyWALL 35 User s Guide 232 Chapter 13 Introduction to IPSec ...
Page 275: ...ZyWALL 35 User s Guide Chapter 15 Certificates 273 Figure 129 My Certificate Details ...
Page 294: ...ZyWALL 35 User s Guide 292 Chapter 16 Authentication Server Figure 140 Local User Database ...
Page 314: ...ZyWALL 35 User s Guide 312 Chapter 17 Network Address Translation NAT ...
Page 318: ...ZyWALL 35 User s Guide 316 Chapter 18 Static Route ...
Page 324: ...ZyWALL 35 User s Guide 322 Chapter 19 Policy Route ...
Page 340: ...ZyWALL 35 User s Guide 338 Chapter 20 Bandwidth Management ...
Page 376: ...ZyWALL 35 User s Guide 374 Chapter 22 Remote Management ...
Page 390: ...ZyWALL 35 User s Guide 388 Chapter 24 Logs Screens Figure 198 Log Settings ...
Page 413: ...ZyWALL 35 User s Guide Chapter 25 Maintenance 411 Figure 220 Restart Screen ...
Page 414: ...ZyWALL 35 User s Guide 412 Chapter 25 Maintenance ...
Page 440: ...ZyWALL 35 User s Guide 438 Chapter 28 WAN and Dial Backup Setup ...
Page 456: ...ZyWALL 35 User s Guide 454 Chapter 31 DMZ Setup ...
Page 460: ...ZyWALL 35 User s Guide 458 Chapter 32 Route Setup ...
Page 470: ...ZyWALL 35 User s Guide 468 Chapter 33 Remote Node Setup ...
Page 522: ...ZyWALL 35 User s Guide 520 Chapter 39 System Information Diagnosis ...
Page 538: ...ZyWALL 35 User s Guide 536 Chapter 40 Firmware and Configuration File Maintenance ...
Page 550: ...ZyWALL 35 User s Guide 548 Chapter 42 Remote Management ...
Page 558: ...ZyWALL 35 User s Guide 556 Chapter 43 IP Policy Routing ...
Page 574: ...ZyWALL 35 User s Guide 572 Chapter 45 Troubleshooting Figure 364 Java Sun ...
Page 602: ...ZyWALL 35 User s Guide 600 Appendix C IP Subnetting ...
Page 608: ...ZyWALL 35 User s Guide 606 Appendix E PPTP ...
Page 626: ...ZyWALL 35 User s Guide 624 Appendix G Triangle Route ...
Page 656: ...ZyWALL 35 User s Guide 654 Appendix J Importing Certificates ...
Page 658: ...ZyWALL 35 User s Guide 656 Appendix K Command Interpreter ...
Page 664: ...ZyWALL 35 User s Guide 662 Appendix L Firewall Commands ...
Page 668: ...ZyWALL 35 User s Guide 666 Appendix M NetBIOS Filter Commands ...
Page 674: ...ZyWALL 35 User s Guide 672 Appendix O Brute Force Password Guessing Protection ...
Page 696: ...ZyWALL 35 User s Guide 694 Appendix Q Log Descriptions ...