how to identify dns server that can support tcp conn reuse?

[Nyx2022]

hello ,i found this lib is complex with some dns protocols supported,and i wanna use dns over tcp,i found you use pipeline to speedup,but it has a err in https://github.com/folbricht/routedns/blob/master/pipeline.go. line 145,when the err is eof,o the conn must be closed, which means that the dns server can not support send multi dns query in one tcp connection, so i wanna know how can i detect some dns server if support send multi dns query in one tcp connection,or is there any method to let dns server know that i wanna send multi dns query in one tcp connection.

[folbricht]

Can you describe what isn't working as expected. I'm pretty sure pipelining allows sending multiple queries through a single connection. Are you having issues with some TCP server that doesn't allow it and closes the connection? You can run routedns -l6 ... to enable full logging and I believe that would show when servers close the connections.

[Nyx2022]

ok,thank you ,i think your lib is very well,my need is wanna identify dns server if support sending multiple queries through a single tcp connection,if not ,i will not use it again,except by -16 to test many queries,is there any other methods by check some flag in response?

[folbricht]

I don't know of a way to easily identify TCP DNS servers that don't support connection-reuse. On the other hand, I haven't seen one that doesn't allow multiple queries to be sent over a single connection. Are you sure that's a problem you're having?

[Nyx2022]

yes ,perhaps it's my mistake ,i'll wend here when i gotten the bad dns server