For reference: https://datatracker.ietf.org/doc/html/rfc7873#section-5.4
Over the last couple of months I've been purposely tracking "Querying for a Server Cookie" as described in the link above. And I have seen zero such queries. Nada. Zilch. Nothinkski. As best I can tell, "dig" is incapable of issuing such a query so one presumes that even ISC don't think it a very important use-case even tho their name is on the RFC. Furthermore, my DNS decoder of choice (github.com/miekg/dns) discards inbound queries with QD!=1 (but it at least offers an escape hatch which I used for the aforementioned tracking). In short, QD=0 is an odd query which is not well supported. Furthermore, I suspect that most middleware and some firewalls are going to drop them with prejudice, all of which means that a #5.4 query has a number of barriers to overcome. But zero such queries after watching for months? That's surprising. I'm obviously suspicion of my tracking code, but I've checked as best I can. Two questions: a) Are there known #5.4 implementations out there? b) Have others seen such queries in the wild? I guess a final question: Are DNS Cookies considered BCP and thus I should be expecting #5.4 queries now or in the near future? I've read a few dissenting views is why I ask. Mark. _______________________________________________ dns-operations mailing list [email protected] https://lists.dns-oarc.net/mailman/listinfo/dns-operations
