Connection

Selecting the Connection node gives you an overview of DNS server settings.

General tab

Figure. Connection management: General tab.

Field	Description
DNS Server	Specify IP addresses for your DNS servers here. Separate multiple entries by semicolons. You should specify two or three DNS servers so if one is unavailable, then the second one can be accessed and so on. Examples of public DNS servers: OpenDNS (208.67.220.220), Google (8.8.8.8), level3 (4.2.2.1). Note: IceWarp Server will attempt to locate your DNS servers automatically on the initial installation. (Or click on the ":" button to automatically fetch the DNS servers specified in your server's NIC. If connection is not available, the server tries also system DNS (Windows configured).)
DNS query timeout (Sec)	The amount of time (in seconds) to wait for a DNS server response before considering this a timeout and trying the next DNS server in your list. This timeout is used for each defined DNS server (if accessed). In performance logs, the total timeout is logged.
Use DNS query cache	Allows IceWarp Serverto cache the results of DNS queries, which can greatly enhance server performance on high load servers.
DNS query cache items limit	Specify the number of DNS queries to be cached. The higher the number, the greater the performance improvement can be, but we recommend not specifying a value greater than 2000 as the cache will use up some of your server's memory.
Test DNS Server	Use this button to test the functionality of the servers you specified. You should always perform this test when you add or change DNS servers. Just connection to the specified DNS server(s) is tested.
DNS Tool	Click the button to open the DNS Tool dialog. See DNS Tool.