ZyXEL Communications vantage cnm ユーザーズマニュアル

 Chapter 7 Device Advanced Settings

Vantage CNM User’s Guide

Use this screen to configure a device’s DNS caching. To open this screen, click a device, click 
Device Operation and then click Device Configuration > Advanced > DNS > Cache in the 
navigation panel.

Figure 100   Device Operation > Device Configuration > Advanced > DNS > Cache

The following table describes the labels in this screen.

Apply

Click Apply to save your changes back to the device.

Cancel

Click Cancel to exit this screen without saving.

Table 90   Device Operation > Device Configuration > Advanced > DNS > Name Server 

Record > Add/Edit (continued)

Table 91   Device Operation > Device Configuration > Advanced > DNS > Cache

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 device’s processing of 

commonly queried domain names and reduces the amount of traffic that the 

device sends out to the WAN.

Maximum TTL

Type the maximum time to live (TTL) (60 to 3600 seconds). This sets how long 

the device 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 device’s processing of 

commonly queried domain names (for which DNS resolution has failed) and 

reduces the amount of traffic that the device sends out to the WAN.

Negative Cache 

Period

Type the time (60 to 3600 seconds) that the device 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 device.

Reset

Click Reset to begin configuring this screen afresh.