With Windows 2000 the DNS Client caches the DNS lookups, so it doesn't have to spend time on contacting the DNS Server all the time, and decreases the traffic to the DNS server. But negative DNS replies are also cached and used for up to 15 min before it again requests the DNS Server. This waiting time can be annoying if the domain is correct and the DNS Server just were sick for a moment. The waiting time can be configured with these DWORD values:
Note using 5 sec instead of 0 sec to throttle the requests to the DNS Server in case a faulty application loops around a DNS Lookup.[HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet \Services \Dnscache \Parameters]
NegativeCacheTime = 5 (Win2k Default 300 sec)
MaxNegativeCacheTtl = 5 (WinXP/Win2k3 Default 900 sec)
Note to see the contents of the DNS cache:
Note to empty/flush/reset the DNS cache manually (Part of WinXP Network Repair):ipconfig /displaydns
Note to flush the Address Resolution Protocol (ARP) cache of Ethernet Addresses (Part of WinXP Network Repair):ipconfig /flushdns
Note to purge and reload the NetBIOS cache (Part of WinXP Network Repair):arp -d *
netsh interface ip delete arpcache
More Info MS KB245437nbtstat -R
More Info MS KB297510
More Info MS KB318803
Related Microsoft TCP/IP Version 6 (IPv6) can cause slow DNS
Credits Navas Cable Guide
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