Typically the TCP connections to DNS servers are expected to be short lived, ie: the client connects, sends the query and disconnects on getting the response.

If a client wants to keep a long lived TCP connection to a DNS server and use it whenever a query has to be sent, is this a safe/acceptable practice ? For DNS servers long lived TCP connections could be construed as a DOS attack. Do DNS servers typically track TCP connections and try to close the long lived ones ?


The existing approved DNS-related RFCs actually don't cover DNS request pipelining, though it wouldn't take much to get there.

Check out this draft of an update to RFC 5966 for example, which seems to be close to publication and which addresses precisely this topic: https://datatracker.ietf.org/doc/draft-ietf-dnsop-5966bis/?include_text=1

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.