CODEWITHSUNDEEP
windowsdnstcpnameservers
user128602
user128602

Reputation: 253

Programmatically Changing NameServer in Windows TCP/IP

I am building a VPN application where I need to set DNS server programmatically. I am changing NameServer parameter in the registry (in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces) to prepend a name server to the list of existing entries. Once I do this, if I try to look up a host name using nslookup, it works fine, but ping is not able to resolve the name - for 15 minutes. And after 15 mins ping is also able to resolve the name. I've tried my own little TCP/IP app, and that has the same issue. I looked at the traffic in wireshark, and I see that nslookup is sending dns lookup requests, while ping isn't.

Is there anyway I can kick windows to notice the name server earlier? Or is there a better way to set name servers in windows?

Thanks in advance for your help!

Upvotes: 3

Views: 3382

Answers (1)

ephemient
ephemient

Reputation: 204964

Don't change that registry key directly. As you've found, it doesn't notify DNS clients that the nameserver has changed.

The easiest solution is probably %SystemRoot%\system32\netsh.exe.

netsh interface ip set dns name="Local Area Connection" source=static addr=...

Upvotes: 4

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