On 13 May 2026, at 14:28, Anand Buddhdev <anandb@ripe.net> wrote:
On 13/05/2026 13:20, Peter Eckel via dns-wg wrote:
Hi Peter,
Yes, the RFC is essentially correct, and using a / in a label is not forbidden either. You can do that, which doesn't mean that you should :-) The big problem with using a slash is that if your zone files are based on the zone name (almost universal practice), then on unix-like systems, where the slash is a path separator, you'll have a problem. You'll have to give the file a different name, and it quickly becomes messy. A dash doesn't pose any such problems.
I have always found RFC 2317 to be a little too prescriptive. I would have preferred it if it had just said "Reverse DNS is just a naming convention, a zone is a zone, CNAME and PTR records are things that can be put in zones, feel free to connect the dots" with the proposed / notation being more clearly an example of that. In the past when hand-editing zone files was a thing I have found it convenient, for example, to $ORIGIN 90.212.199.IN-ADDR.ARPA. @ IN SOA ... @ NS ... $GENERATE 0-255 $ CNAME $.reverse.HOPCOUNT.CA. $ORIGIN HOPCOUNT.CA. @ IN SOA ... @ NS ... ; delightful.hopcount.ca. A 199.212.90.1 1.reverse PTR delightful.HOPCOUNT.CA. ; glorious.hopcount.ca. A 199.212.90.37 37.reverse PTR glorious.HOPCOUNT.CA. This to me seems fully in the spirit of 2317 and has the advantage of keeping data that should match together, so that when it doesn't match it's more obvious. No innocent punctuation was harmed in the formulation of this example. Joe