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Label compression is pretty common, I think all of the big name server implementations do it by default. Amazon Route 53 definitely does it - I wrote the code! But my favorite thing about DNS label compression is probably this quote from DJB's code where he implemented it ...

https://github.com/abh/djbdns/blob/0715ca5de14ad5eae2c779c53...

Yeah, label compression is very much in use. It is annoying though, it’s one of the slower pieces during serialization.

Thanks! I've only been hacking around with dns as an amateur so i appreciate the correction.

> I appreciate that this is a work in progress but this section is misleading. As all too briefly mentioned elsewhere on the page, EDNS allows extending this. In practice most of the resolvers I connect to do support EDNS and a buffer of 4096. So yes 512 may be needed as a fallback (depending on what you're doing) but you'll almost certainly have more room to breathe than that. IPv6 and DNSSEC practically make the extra space a necessity.

EDNS is fundamental DNS knowledge that any DNS server implementer knows and Bert is one. He's talking about "when DNS was created" in that context, i.e., the current DNS's RFC 1034/1035 times.

Hi Muks! The rest of the content is still appearing, but https://powerdns.org/hello-dns/optional.md.html now talks about EDNS.

This needs an update, but here is a study I made a while back on EDNS support and payload sizes: http://msync.c9x.org/PubDNS/