1. aws/elb.amazonaws.com
2. delegation
$ dig -t ns elb.amazonaws.com @a.gtld-servers.net ; <<>> DiG 9.9.5-3ubuntu0.5-Ubuntu <<>> -t ns elb.amazonaws.com @a.gtld-servers.net ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 59408 ;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 4, ADDITIONAL: 5 ;; WARNING: recursion requested but not available ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4096 ;; QUESTION SECTION: ;elb.amazonaws.com. IN NS ;; AUTHORITY SECTION: amazonaws.com. 172800 IN NS u1.amazonaws.com. amazonaws.com. 172800 IN NS u2.amazonaws.com. amazonaws.com. 172800 IN NS r1.amazonaws.com. amazonaws.com. 172800 IN NS r2.amazonaws.com. ;; ADDITIONAL SECTION: u1.amazonaws.com. 172800 IN A 156.154.64.10 u2.amazonaws.com. 172800 IN A 156.154.65.10 r1.amazonaws.com. 172800 IN A 205.251.192.27 r2.amazonaws.com. 172800 IN A 205.251.195.199 ;; Query time: 174 msec ;; SERVER: 192.5.6.30#53(192.5.6.30) ;; WHEN: Thu Dec 03 05:52:57 JST 2015 ;; MSG SIZE rcvd: 178
3. NOERROR -> nodata
$ dig -t ns elb.amazonaws.com @156.154.64.10
; <<>> DiG 9.9.5-3ubuntu0.5-Ubuntu <<>> -t ns elb.amazonaws.com @156.154.64.10 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 29018 ;; flags: qr aa rd; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1 ;; WARNING: recursion requested but not available ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 65235 ;; QUESTION SECTION: ;elb.amazonaws.com. IN NS ;; AUTHORITY SECTION: amazonaws.com. 5 IN SOA pdns1.ultradns.net. hostmaster.amazon.com. 2014060298 180 60 2592000 5 ;; Query time: 12 msec ;; SERVER: 156.154.64.10#53(156.154.64.10) ;; WHEN: Thu Dec 03 05:53:11 JST 2015 ;; MSG SIZE rcvd: 118
$ dig -t ns elb.amazonaws.com @156.154.65.10
; <<>> DiG 9.9.5-3ubuntu0.5-Ubuntu <<>> -t ns elb.amazonaws.com @156.154.65.10 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 16429 ;; flags: qr aa rd; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1 ;; WARNING: recursion requested but not available ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 65235 ;; QUESTION SECTION: ;elb.amazonaws.com. IN NS ;; AUTHORITY SECTION: amazonaws.com. 5 IN SOA pdns1.ultradns.net. hostmaster.amazon.com. 2014060298 180 60 2592000 5 ;; Query time: 14 msec ;; SERVER: 156.154.65.10#53(156.154.65.10) ;; WHEN: Thu Dec 03 05:58:44 JST 2015 ;; MSG SIZE rcvd: 118
4. NXDOMAIN response
$ dig -t ns elb.amazonaws.com @205.251.192.27 ; <<>> DiG 9.9.5-3ubuntu0.5-Ubuntu <<>> -t ns elb.amazonaws.com @205.251.192.27 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 26995 ;; flags: qr aa rd; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1 ;; WARNING: recursion requested but not available ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4096 ;; QUESTION SECTION: ;elb.amazonaws.com. IN NS ;; AUTHORITY SECTION: amazonaws.com. 7200 IN SOA dns-external-master.amazon.com. hostmaster.amazon.com. 2012091400 180 60 2592000 5 ;; Query time: 142 msec ;; SERVER: 205.251.192.27#53(205.251.192.27) ;; WHEN: Thu Dec 03 05:56:11 JST 2015 ;; MSG SIZE rcvd: 120
$ dig -t ns elb.amazonaws.com. @205.251.195.199 ; <<>> DiG 9.9.5-3ubuntu0.5-Ubuntu <<>> -t ns elb.amazonaws.com. @205.251.195.199 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 35794 ;; flags: qr aa rd; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1 ;; WARNING: recursion requested but not available ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4096 ;; QUESTION SECTION: ;elb.amazonaws.com. IN NS ;; AUTHORITY SECTION: amazonaws.com. 7200 IN SOA dns-external-master.amazon.com. hostmaster.amazon.com. 2012091400 180 60 2592000 5 ;; Query time: 14 msec ;; SERVER: 205.251.195.199#53(205.251.195.199) ;; WHEN: Thu Dec 03 05:35:07 JST 2015 ;; MSG SIZE rcvd: 120
$ dig -t ns elb.amazonaws.com. @205.251.192.27 ; <<>> DiG 9.9.5-3ubuntu0.5-Ubuntu <<>> -t ns elb.amazonaws.com. @205.251.192.27 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 30436 ;; flags: qr aa rd; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1 ;; WARNING: recursion requested but not available ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4096 ;; QUESTION SECTION: ;elb.amazonaws.com. IN NS ;; AUTHORITY SECTION: amazonaws.com. 7200 IN SOA dns-external-master.amazon.com. hostmaster.amazon.com. 2012091400 180 60 2592000 5 ;; Query time: 144 msec ;; SERVER: 205.251.192.27#53(205.251.192.27) ;; WHEN: Thu Dec 03 05:36:36 JST 2015 ;; MSG SIZE rcvd: 120
$ dig -t ns elb.amazonaws.com. @127.0.0.3 ; <<>> DiG 9.9.5-3ubuntu0.5-Ubuntu <<>> -t ns elb.amazonaws.com. @127.0.0.3 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 39278 ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4096 ;; QUESTION SECTION: ;elb.amazonaws.com. IN NS ;; AUTHORITY SECTION: amazonaws.com. 7200 IN SOA dns-external-master.amazon.com. hostmaster.amazon.com. 2012091400 180 60 2592000 5 ;; Query time: 15 msec ;; SERVER: 127.0.0.3#53(127.0.0.3) ;; WHEN: Thu Dec 03 05:30:56 JST 2015 ;; MSG SIZE rcvd: 120
[plan] plan 'elb.amazonaws.com.' type 'NS' [resl] => querying: '205.251.195.199' score: 10 zone cut: 'amazonaws.com.' m12n: 'ELB.amaZoNaWs.CoM.' type: 'NS' [resl] optional: '205.251.192.27' score: 10 zone cut: 'amazonaws.com.' m12n: 'ELB.amaZoNaWs.CoM.' type: 'NS' [iter] <= rcode: NXDOMAIN [ pc ] => answer cached for TTL=900 [resl] finished: 4, queries: 1, mempool: 49200 B