Unresponsive or nonexistent domain name servers in DNS
configuration greatly increases response time for the server.
The default value for TCPIP's RESOLVERTIMEOUT requests is 30 seconds.
TCPIP uses a preconfigured set of Domain Name Servers each time an IP
hostname or IP hostaddr lookup occurs. If the first server listed in the
set is not available, TCPIP will wait for 30 seconds before attempting to
use the second server in the list. Each subsequent non-operational DNS
server listed will add 30 more seconds to the lookup response time. There
can be several lookups per request in the server, and this can add several
minutes to the response time for each request.
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