ZyXEL ZyWALL 5 User Guide - Page 486
DNS Screens, ZyWALL 5/35/70 Series User's Guide, ADVANCED > DNS > Cache
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Chapter 26 DNS Screens Figure 277 ADVANCED > DNS > Cache The following table describes the labels in this screen. 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. 486 ZyWALL 5/35/70 Series User's Guide
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