On Sat, Oct 25, 2014 at 11:57 AM, Stephane Bortzmeyer <[email protected]> wrote: > On Mon, Oct 20, 2014 at 05:26:29PM -0400, > Phillip Hallam-Baker <[email protected]> wrote > a message of 74 lines which said: > >> If we are going there, I would want to know how common the >> configurations are. > > Yes, actual numbers seen from a real resolver would be useful. > >> Outside this list how common are hierarchies more than 4 levels deep >> in practice?
Surprisingly enough, not an insignificant number -- but this is mitigated by what the queries are (see below) > > ip6.arpa, and other infrastructure domains? There is a long tail, but: ~51% of lookups are of length 3 (www.example.com) ~23% of lookups are of length 5 (this was surprising to me, but is largely dominated by Akamai - www.example.com.akadns.net) ~15% of lookups are of length 4 (usually service.something.largecompany.com) This means that lengths 3, 4, 5 account for ~89% of lookups. If you include lengths of 1 and 2 you get >96% Many of these (like the akamai ones, .com, etc) look like they would cache every well... In the long tail there are the ip6.arpa, in-addr.arpa, some dnsbls and then a bunch of anti-virus / web-filter stuff (things like <really long b64(?) encoded string>.sophosxl.com or <some opaque string>.avts.mcafee.com), and some "obviously" broken queries www.www.www.www.www.www.www.www.www.cnn.com) So, while looking at this I stumbled across something, um, odd... wkumari@vimes:~$ dig ns +noall +comments apple.com.akadns.net ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 27395 ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4096 'kay... wkumari@vimes:~$ dig ns +noall +comments com.akadns.net ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 3341 ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4096 Er... wouldn't this break with qnm? (obviously fixable, but an interesting data point). It has been a long day, so perhaps I'm missing something as well... W -- I don't think the execution is relevant when it was obviously a bad idea in the first place. This is like putting rabid weasels in your pants, and later expressing regret at having chosen those particular rabid weasels and that pair of pants. ---maf _______________________________________________ DNSOP mailing list [email protected] https://www.ietf.org/mailman/listinfo/dnsop
