NEDNSProxyProvider and TCP

Question

Jean-Daniel From Paris OP

Created Oct ’24

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Hello,

I'm wondering if a NEDNSProxyProvider should supports TCP DNS query or not ?

DNS UDP datagrams are limited to 512 bytes and sometimes, a DNS resolver should fallback to TCP to handle large queries.

But I don't see anything about supporting TCP flow in the DNS Proxy provider reference.

Is there a guarantee that it will only receive UDP flow ? How is the system handling large DNS queries in that case ?

Answered by Jean-Daniel From Paris in 810415022

I found the answer myself.

TCP connection handling is required too. Some software rely on TCP DNS queries, and they are properly passed to the NEDNSProxyProvider as NEAppProxyTCPFlow.

To simply test that case, it is possible to use dig +tcp www.example.com in the terminal.

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Answer 1

Jean-Daniel From Paris OP

Oct ’24

Accepted Answer

I found the answer myself.

TCP connection handling is required too. Some software rely on TCP DNS queries, and they are properly passed to the NEDNSProxyProvider as NEAppProxyTCPFlow.

To simply test that case, it is possible to use dig +tcp www.example.com in the terminal.

1