On Sat, Jun 18, 2011 at 1:35 PM, Owen DeLong <owen@delong.com> wrote:
This ignores the extra baggage that tends to come along in a DNS payload. Just the root: ..... Note, none of these came with glue. They ONLY included the name data. Had they come with glue, we would easily have been over 512 in both cases just for IPv4, let alone a v4/v6 combination.
None of those come with glue, ....really? For the root zone, I currently see a fully populated NS response with a fair bit of glue that is 512 bytes total, and a majority of that 512 bytes response is the additional section. That is, with no glue, you would be looking at approximately 200 octets. In addition when I dig against 2001:dc3::35, the root server responds to my query IN with glue for all A through L .root-servers, and two pieces of AAAA glue without exceeding 492 message size. However, the root zone and gTLD zones are quite special, and a very significant exception to the norm for number of NS entries authoritative for a zone. Few domains have more than 3 NS. ;; MSG SIZE rcvd: 512 # dig +norecurse -t NS . @198.41.0.4 ; <<>> DiG 9.3.6-P1-RedHat-9.3.6-16.P1.el5 <<>> +norecurse -t NS . @198.41.0.4 ;; global options: printcmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 46162 ;; flags: qr aa; QUERY: 1, ANSWER: 13, AUTHORITY: 0, ADDITIONAL: 14 ;; QUESTION SECTION: ;. IN NS ;; ANSWER SECTION: . 518400 IN NS b.root-servers.net. . 518400 IN NS e.root-servers.net. . 518400 IN NS k.root-servers.net. . 518400 IN NS m.root-servers.net. . 518400 IN NS f.root-servers.net. . 518400 IN NS c.root-servers.net. . 518400 IN NS g.root-servers.net. . 518400 IN NS j.root-servers.net. . 518400 IN NS h.root-servers.net. . 518400 IN NS d.root-servers.net. . 518400 IN NS a.root-servers.net. . 518400 IN NS i.root-servers.net. . 518400 IN NS l.root-servers.net. ;; ADDITIONAL SECTION: b.root-servers.net. 3600000 IN A 192.228.79.201 e.root-servers.net. 3600000 IN A 192.203.230.10 k.root-servers.net. 3600000 IN A 193.0.14.129 k.root-servers.net. 3600000 IN AAAA 2001:7fd::1 m.root-servers.net. 3600000 IN A 202.12.27.33 m.root-servers.net. 3600000 IN AAAA 2001:dc3::35 f.root-servers.net. 3600000 IN A 192.5.5.241 f.root-servers.net. 3600000 IN AAAA 2001:500:2f::f c.root-servers.net. 3600000 IN A 192.33.4.12 g.root-servers.net. 3600000 IN A 192.112.36.4 j.root-servers.net. 3600000 IN A 192.58.128.30 j.root-servers.net. 3600000 IN AAAA 2001:503:c27::2:30 h.root-servers.net. 3600000 IN A 128.63.2.53 h.root-servers.net. 3600000 IN AAAA 2001:500:1::803f:235 ;; Query time: 203 msec ;; SERVER: 198.41.0.4#53(198.41.0.4) ;; WHEN: Sun Jun 19 13:17:31 2011 ;; MSG SIZE rcvd: 512 # dig +norecurse -t NS . @2001:dc3::35 ; <<>> DiG 9.3.6-P1-RedHat-9.3.6-16.P1.el5 <<>> +norecurse -t NS . @m.root-servers.net ;; global options: printcmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 1931 ;; flags: qr aa; QUERY: 1, ANSWER: 13, AUTHORITY: 0, ADDITIONAL: 15 ;; QUESTION SECTION: ;. IN NS ;; ANSWER SECTION: . 518400 IN NS c.root-servers.net. . 518400 IN NS j.root-servers.net. . 518400 IN NS h.root-servers.net. . 518400 IN NS g.root-servers.net. . 518400 IN NS b.root-servers.net. . 518400 IN NS f.root-servers.net. . 518400 IN NS l.root-servers.net. . 518400 IN NS i.root-servers.net. . 518400 IN NS m.root-servers.net. . 518400 IN NS d.root-servers.net. . 518400 IN NS k.root-servers.net. . 518400 IN NS e.root-servers.net. . 518400 IN NS a.root-servers.net. ;; ADDITIONAL SECTION: a.root-servers.net. 3600000 IN A 198.41.0.4 b.root-servers.net. 3600000 IN A 192.228.79.201 c.root-servers.net. 3600000 IN A 192.33.4.12 d.root-servers.net. 3600000 IN A 128.8.10.90 e.root-servers.net. 3600000 IN A 192.203.230.10 f.root-servers.net. 3600000 IN A 192.5.5.241 g.root-servers.net. 3600000 IN A 192.112.36.4 h.root-servers.net. 3600000 IN A 128.63.2.53 i.root-servers.net. 3600000 IN A 192.36.148.17 j.root-servers.net. 3600000 IN A 192.58.128.30 k.root-servers.net. 3600000 IN A 193.0.14.129 l.root-servers.net. 3600000 IN A 199.7.83.42 m.root-servers.net. 3600000 IN A 202.12.27.33 a.root-servers.net. 3600000 IN AAAA 2001:503:ba3e::2:30 d.root-servers.net. 3600000 IN AAAA 2001:500:2d::d ;; Query time: 88 msec ;; SERVER: 2001:dc3::35#53(2001:dc3::35) ;; WHEN: Sun Jun 19 13:35:41 2011 ;; MSG SIZE rcvd: 492 -- -JH