ZyXEL Communications ZyXEL ZyWALL 35 - Manual (Page 346)

ZyWALL 35 User’s Guide
344 Chapter 20 DNS
20.8 Configure DNS Cache
To configure your ZyWALL’s DNS caching, click DNS, then the Cache tab. The screen
appears as shown.
Figure 171 Cache
The following table describes the labels in this screen.
Table 118 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.