<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div dir="ltr">On May 6, 2021, at 09:44, Gerben Wierda via Unbound-users <unbound-users@lists.nlnetlabs.nl> wrote:</div><div dir="ltr"><br></div><div dir="ltr"><blockquote type="cite">That is also a good option. It really surprised me as I did not know that TCP was a hard requirement for queries. In my old know how, TCP was for zone transfers, but not for queries, but I admit I never dove into it extremely deep. Naive, no, but lacking knowledge, yes (those are not the same...).</blockquote></div><br><div>This seems like a good opportunity to recommend this document, which was written precisely to address this kind of thing from an operational perspective:</div><div><br></div><div><a href="https://tools.ietf.org/html/draft-ietf-dnsop-dns-tcp-requirements-07">https://tools.ietf.org/html/draft-ietf-dnsop-dns-tcp-requirements-07</a></div><div><br></div><div>I'm sure the authors would welcome feedback if you have any. It's a good read, even if you don't :-)</div><div><br></div><div><br></div><div>Joe</div></body></html>