Да, DNS выполняют рекурсивные запросы.
Утилита host почему-то не отрабатывает, если указать принудительно dns сервер.
Попробуйте dig
digxaker1@xaker1:~ > dig -t ns f.root-servers.net. ru.
; <<>> DiG 9.9.2-P1 <<>> -t ns f.root-servers.net. ru.
;; global options: +cmd
;; Got answer:
;; ->>HEADER<< — opcode: QUERY, status: NOERROR, id: 55260
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0
;; QUESTION SECTION:
;f.root-servers.net. IN NS
;; AUTHORITY SECTION:
root-servers.net. 3600 IN SOA a.root-servers.net. nstld.verisign-grs.com. 2013010300 14400 7200 1209600 3600000
;; Query time: 3 msec
;; SERVER: 127.0.1.1#53(127.0.1.1)
;; WHEN: Thu Aug 1 17:21:15 2013
;; MSG SIZE rcvd: 96
;; Got answer:
;; ->>HEADER<< — opcode: QUERY, status: NOERROR, id: 11972
;; flags: qr rd ra; QUERY: 1, ANSWER: 5, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;ru. IN NS
;; ANSWER SECTION:
ru. 84996 IN NS f.dns.ripn.net.
ru. 84996 IN NS e.dns.ripn.net.
ru. 84996 IN NS a.dns.ripn.net.
ru. 84996 IN NS d.dns.ripn.net.
ru. 84996 IN NS b.dns.ripn.net.
;; Query time: 3 msec
;; SERVER: 127.0.1.1#53(127.0.1.1)
;; WHEN: Thu Aug 1 17:21:15 2013
;; MSG SIZE rcvd: 112
xaker1@xaker1:~ > dig -t a habr.ru. +trace +all
; <<>> DiG 9.9.2-P1 <<>> -t a habr.ru. +trace +all
;; global options: +cmd
;; Got answer:
;; ->>HEADER<< — opcode: QUERY, status: NOERROR, id: 9020
;; flags: qr ra; QUERY: 1, ANSWER: 13, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;. IN NS
;; ANSWER SECTION:
. 516394 IN NS d.root-servers.net.
. 516394 IN NS m.root-servers.net.
. 516394 IN NS l.root-servers.net.
. 516394 IN NS f.root-servers.net.
. 516394 IN NS a.root-servers.net.
. 516394 IN NS i.root-servers.net.
. 516394 IN NS c.root-servers.net.
. 516394 IN NS g.root-servers.net.
. 516394 IN NS j.root-servers.net.
. 516394 IN NS b.root-servers.net.
. 516394 IN NS k.root-servers.net.
. 516394 IN NS e.root-servers.net.
. 516394 IN NS h.root-servers.net.
;; Query time: 508 msec
;; SERVER: 208.67.222.222#53(208.67.222.222)
;; WHEN: Thu Aug 1 17:09:13 2013
;; MSG SIZE rcvd: 239
;; Got answer:
;; ->>HEADER<< — opcode: QUERY, status: NOERROR, id: 13022
;; flags: qr; QUERY: 1, ANSWER: 0, AUTHORITY: 7, ADDITIONAL: 11
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags: do; udp: 4096
;; QUESTION SECTION:
;habr.ru. IN A
;; AUTHORITY SECTION:
ru. 172800 IN NS a.dns.ripn.net.
ru. 172800 IN NS e.dns.ripn.net.
ru. 172800 IN NS f.dns.ripn.net.
ru. 172800 IN NS b.dns.ripn.net.
ru. 172800 IN NS d.dns.ripn.net.
ru. 86400 IN DS 14072 8 2 DFFBFE59FBBD3289D0C3819F05F94610A1E03B556D64540A2CC5F8C4 158A00E7
ru. 86400 IN RRSIG DS 8 1 86400 20130807000000 20130730230000 49656. kO5UkU+BBko5+QDOkU6jkerC6WzsEqMHxc+RVfE+y3e8PPWI+HKHBj6Z e6/x4Ddn4BpUBM732dWbz88n00PqFhD3Q+00RM+7YwPnEDmDk1eZJrJT 33opWG5L8hn+5DYoHRPuSGJBcRhyIQHwHWwvhtiX7IsPj2GmskUssBLG 6ro=
;; ADDITIONAL SECTION:
a.dns.ripn.net. 172800 IN A 193.232.128.6
b.dns.ripn.net. 172800 IN A 194.85.252.62
d.dns.ripn.net. 172800 IN A 194.190.124.17
e.dns.ripn.net. 172800 IN A 193.232.142.17
f.dns.ripn.net. 172800 IN A 193.232.156.17
a.dns.ripn.net. 172800 IN AAAA 2001:678:17:0:193:232:128:6
b.dns.ripn.net. 172800 IN AAAA 2001:678:16:0:194:85:252:62
d.dns.ripn.net. 172800 IN AAAA 2001:678:18:0:194:190:124:17
e.dns.ripn.net. 172800 IN AAAA 2001:678:15:0:193:232:142:17
f.dns.ripn.net. 172800 IN AAAA 2001:678:14:0:193:232:156:17
;; Query time: 243 msec
;; SERVER: 199.7.91.13#53(199.7.91.13)
;; WHEN: Thu Aug 1 17:09:13 2013
;; MSG SIZE rcvd: 555
;; Got answer:
;; ->>HEADER<< — opcode: QUERY, status: NOERROR, id: 22012
;; flags: qr; QUERY: 1, ANSWER: 0, AUTHORITY: 6, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags: do; udp: 4096
;; QUESTION SECTION:
;habr.ru. IN A
;; AUTHORITY SECTION:
habr.ru. 345600 IN NS ns2.habradns.net.
habr.ru. 345600 IN NS ns1.habradns.net.
TDUI9D4JKUDS8B9T86GJ39PGFLCNLGM5.ru. 3600 IN NSEC3 1 1 3 00FF TEFG7J6PMM47P5H81JFQ4VC5FIS9TDOL NS SOA RRSIG DNSKEY NSEC3PARAM
TDUI9D4JKUDS8B9T86GJ39PGFLCNLGM5.ru. 3600 IN RRSIG NSEC3 8 2 3600 20130818050420 20130711212102 9879 ru. uHu+S8E4WHqaTPtZhxOWcvOFvfGyPg3gmZb4COgF+W+pXrx9HIZbT0UP Bidi9p94FwfpxRrV9oz1QXooF9Q9oLU/1l0Hc/2r6HyY7RTpZDeRQlnt Fy6LHVboDazKHBm50XAU15IidiIgzG9cZV69ITT0kqMqxUR0zVXwFc6J 8zg=
BELG7FO0P653NH4HS77LQ0E5E0MV4JIF.ru. 3600 IN NSEC3 1 1 3 00FF BMP1PHBL4O1LE1IPTV9I1AM84T3N48KJ NS DS RRSIG
BELG7FO0P653NH4HS77LQ0E5E0MV4JIF.ru. 3600 IN RRSIG NSEC3 8 2 3600 20130901075644 20130719092154 9879 ru. UdZCtFE/kLSoCBiEGGd9woNFy7kCxWWxr/5zkqpEads3ev+AX1qWjDgg iNrLv4HqzNvaCezTEJNa6UVoPxQxtoq97Z+1EoaMBjuepzbWfYs77GH4 nzCAJX5/DoFNjlIScfY/ghdCEYTqQMQItt4coLTFdsgS+9vp8BVRLEWm Sdc=
;; Query time: 128 msec
;; SERVER: 193.232.142.17#53(193.232.142.17)
;; WHEN: Thu Aug 1 17:09:15 2013
;; MSG SIZE rcvd: 571
;; Got answer:
;; ->>HEADER<< — opcode: QUERY, status: NOERROR, id: 11959
;; flags: qr aa; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags: do; udp: 4096
;; QUESTION SECTION:
;habr.ru. IN A
;; ANSWER SECTION:
habr.ru. 900 IN A 178.63.117.149
;; AUTHORITY SECTION:
habr.ru. 900 IN NS ns2.habradns.net.
habr.ru. 900 IN NS ns1.habradns.net.
;; Query time: 79 msec
;; SERVER: 78.46.61.175#53(78.46.61.175)
;; WHEN: Thu Aug 1 17:09:15 2013
;; MSG SIZE rcvd: 100
