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Background

We have seen some DNS servers block the queries where both ipv4 and ipv6 are queries together from DNS in a single TCP command

The RFC says this is something called DNS pipelining, 6.2.1.1

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Query

I am trying to understand how to simulate this from the command line or C code.

I came across this link but it doesn't issue a single query rather 2 queries one after the other. That is not what I need

Basically I need a way to issue such queries at will to prove to the customer that their DNS is at fault :)

Any pointers how to achieve this ? I am wondering how glibc/resolver is doing it. Tried digging there but could not figure out

Can someone point me to some code ?

mittal
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1 Answers1

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This might be what you're looking for: https://manpages.debian.org/experimental/bind-dnsutils/mdig.1.en.html

mdig is a multiple/pipelined query version of dig: instead of waiting for a response after sending each query, it begins by sending all queries. Responses are displayed in the order in which they are received, not in the order the corresponding queries were sent.

Elizabeth
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