DnsClient.Default.Resolve is returing null in server, even though we got the result in public dns lookup

Question

DnsClient.Default.Resolve is returing null in server, even though we got the result in public dns lookup

Closed this issue a year ago · 9 comments

We got null return in server for some cases.
But when I have tested in my local with the same domain and same functionality we got the result always.
For the same domain, I have also checked here: https://dnschecker.org/ It looks fine.

DnsMessage dnsMessage = DnsClient.Default.Resolve(DomainName.Parse("google.com"), RecordType.Txt) // returns null in server some times

Using Version: "2.2.9"
.Net Version: v4.7.2

Answer 1 · 2023-03-14T18:24:07.000Z

DnsClient.Default uses your locally configured DNS server. Does this server provide the TXT records?

Answer 2 · 2023-03-15T12:18:16.000Z

Yes, it does

Answer 3 · 2023-03-15T12:29:49.000Z

Please provide a wireshark dump where the problem occurs.

Answer 4 · 2023-03-16T08:57:48.000Z

Could you please explain a little bit what do you need to know?

Answer 5 · 2023-03-16T09:23:29.000Z

I need a dump of the DNS network traffic, this can be done using Wireshark.

Answer 6 · 2023-03-16T10:04:43.000Z

I can't share this kind of information.

Answer 7 · 2023-03-16T10:20:52.000Z

Then I cannot help you. I checked it, there is no general issue, so it needs to be debugged if the packages are correct on the network or if there is an issue with the DNS server or on network level.

Answer 8 · 2023-03-16T10:22:14.000Z

You could try to not use the DnsClient.Default but an defined DNS like the Google DNS using a custom DnsClient instance.

Answer 9 · 2023-03-21T08:39:46.000Z

I appreciate your assistance and response, @alexreinert. Unfortunately, I am unable to provide additional information, which makes it difficult to identify any potential security breach on your end. However, I have found an alternative solution and am satisfied with closing the matter.