DNS/dnscache/net-comについて、ここに記述してください。
../nstld.com を調べてみよう。
1. %dnsqr a a.gtld-servers.net
キャッシュを空にして、権威サーバからA レコードを得られるか、queryしてみる。
%dnsqr a a.gtld-servers.net
1 a.gtld-servers.net: 52 bytes, 1+1+0+0 records, response, noerror query: 1 a.gtld-servers.net answer: a.gtld-servers.net 86400 A 192.5.6.30
@40000000569e21d81ff66d2c query 1 7f000001:3717:d4fb 1 a.gtld-servers.net. @40000000569e21d81ff674fc tx 0 1 a.gtld-servers.net. . c0702404 c03a801e c0249411 c0cbe60a c707532a c1000e81 803f0235 80080a5a c6290004 ca0c1b21 c021040c c0e44fc9 c00505f1 @40000000569e21d820ded544 rr c0702404 172800 1 a.gtld-servers.net. c005061e @40000000569e21d820ded92c rr c0702404 172800 1 b.gtld-servers.net. c0210e1e @40000000569e21d820dedd14 rr c0702404 172800 1 c.gtld-servers.net. c01a5c1e @40000000569e21d820dedd14 rr c0702404 172800 1 d.gtld-servers.net. c01f501e @40000000569e21d820dee0fc rr c0702404 172800 1 e.gtld-servers.net. c00c5e1e @40000000569e21d820dee4e4 rr c0702404 172800 1 f.gtld-servers.net. c023331e @40000000569e21d820dee4e4 rr c0702404 172800 1 g.gtld-servers.net. c02a5d1e @40000000569e21d820df17ac rr c0702404 172800 1 h.gtld-servers.net. c036701e @40000000569e21d820df1b94 rr c0702404 172800 1 i.gtld-servers.net. c02bac1e @40000000569e21d820df1b94 rr c0702404 172800 1 j.gtld-servers.net. c0304f1e @40000000569e21d820df1f7c rr c0702404 172800 1 k.gtld-servers.net. c034b21e @40000000569e21d820df2364 rr c0702404 172800 1 l.gtld-servers.net. c029a21e @40000000569e21d820df2364 rr c0702404 172800 1 m.gtld-servers.net. c037531e @40000000569e21d820df36ec rr c0702404 172800 ns net. j.gtld-servers.net. @40000000569e21d820df3ad4 rr c0702404 172800 ns net. b.gtld-servers.net. @40000000569e21d820df3ad4 rr c0702404 172800 ns net. f.gtld-servers.net. @40000000569e21d820df3ebc rr c0702404 172800 ns net. d.gtld-servers.net. @40000000569e21d820df42a4 rr c0702404 172800 ns net. e.gtld-servers.net. @40000000569e21d820df42a4 rr c0702404 172800 ns net. l.gtld-servers.net. @40000000569e21d820df5244 rr c0702404 172800 ns net. i.gtld-servers.net. @40000000569e21d820df5244 rr c0702404 172800 ns net. m.gtld-servers.net. @40000000569e21d820df756c rr c0702404 172800 ns net. g.gtld-servers.net. @40000000569e21d820df756c rr c0702404 172800 ns net. k.gtld-servers.net. @40000000569e21d820df7954 rr c0702404 172800 ns net. c.gtld-servers.net. @40000000569e21d820df7d3c rr c0702404 172800 ns net. a.gtld-servers.net. @40000000569e21d820df7d3c rr c0702404 172800 ns net. h.gtld-servers.net. @40000000569e21d820df8124 rr c0702404 172800 28 a.gtld-servers.net. 20010503a83e00000000000000020030 @40000000569e21d820e005f4 rr c0702404 172800 28 b.gtld-servers.net. 20010503231d00000000000000020030 @40000000569e21d820e009dc stats 1 1005 1 0 @40000000569e21d820e009dc cached 1 j.gtld-servers.net. @40000000569e21d820e00dc4 cached 1 b.gtld-servers.net. @40000000569e21d820e00dc4 cached 1 f.gtld-servers.net. @40000000569e21d820e011ac cached 1 d.gtld-servers.net. @40000000569e21d820e011ac cached 1 e.gtld-servers.net. @40000000569e21d820e0214c cached 1 l.gtld-servers.net. @40000000569e21d820e02534 cached 1 i.gtld-servers.net. @40000000569e21d820e02534 cached 1 m.gtld-servers.net. @40000000569e21d820e0291c cached 1 g.gtld-servers.net. @40000000569e21d820e0291c cached 1 k.gtld-servers.net. @40000000569e21d820e02d04 cached 1 c.gtld-servers.net. @40000000569e21d820e02d04 cached 1 a.gtld-servers.net. @40000000569e21d820e030ec cached 1 h.gtld-servers.net. <<root-serversからnet NSを得た。glue込みで>> <<net NS に問い合わせを送る>> @40000000569e21d820e030ec tx 0 1 a.gtld-servers.net. net. c0304f1e c01f501e c036701e c02bac1e c034b21e c0210e1e c023331e c00c5e1e c02a5d1e c029a21e c005061e c037531e c01a5c1e @40000000569e21d824471df4 rr c0304f1e 172800 ns gtld-servers.net. av1.nstld.com. @40000000569e21d8244721dc rr c0304f1e 172800 ns gtld-servers.net. av2.nstld.com. @40000000569e21d8244725c4 rr c0304f1e 172800 ns gtld-servers.net. av3.nstld.com. @40000000569e21d8244725c4 rr c0304f1e 172800 ns gtld-servers.net. av4.nstld.com. @40000000569e21d8244729ac stats 1 1105 1 0 <<gtld-serversのNSを得た>> <<av1.nstld.comをroot-serversに問い合わせる>> @40000000569e21d824472d94 tx 1 1 av1.nstld.com. . c0e44fc9 c0249411 c021040c c707532a ca0c1b21 c00505f1 c03a801e 803f0235 c0702404 80080a5a c0cbe60a c6290004 c1000e81 @40000000569e21d82b234814 rr c0e44fc9 172800 1 a.gtld-servers.net. c005061e @40000000569e21d82b234bfc rr c0e44fc9 172800 1 b.gtld-servers.net. c0210e1e @40000000569e21d82b234fe4 rr c0e44fc9 172800 1 c.gtld-servers.net. c01a5c1e @40000000569e21d82b234fe4 rr c0e44fc9 172800 1 d.gtld-servers.net. c01f501e @40000000569e21d82b2353cc rr c0e44fc9 172800 1 e.gtld-servers.net. c00c5e1e @40000000569e21d82b2357b4 rr c0e44fc9 172800 1 f.gtld-servers.net. c023331e @40000000569e21d82b2357b4 rr c0e44fc9 172800 1 g.gtld-servers.net. c02a5d1e @40000000569e21d82b238e64 rr c0e44fc9 172800 1 h.gtld-servers.net. c036701e @40000000569e21d82b238e64 rr c0e44fc9 172800 1 i.gtld-servers.net. c02bac1e @40000000569e21d82b23924c rr c0e44fc9 172800 1 j.gtld-servers.net. c0304f1e @40000000569e21d82b239634 rr c0e44fc9 172800 1 k.gtld-servers.net. c034b21e @40000000569e21d82b239634 rr c0e44fc9 172800 1 l.gtld-servers.net. c029a21e @40000000569e21d82b239a1c rr c0e44fc9 172800 1 m.gtld-servers.net. c037531e @40000000569e21d82b23ada4 rr c0e44fc9 172800 ns com. e.gtld-servers.net. @40000000569e21d82b23ada4 rr c0e44fc9 172800 ns com. c.gtld-servers.net. @40000000569e21d82b23b18c rr c0e44fc9 172800 ns com. j.gtld-servers.net. @40000000569e21d82b23b574 rr c0e44fc9 172800 ns com. a.gtld-servers.net. @40000000569e21d82b23b574 rr c0e44fc9 172800 ns com. d.gtld-servers.net. @40000000569e21d82b23b95c rr c0e44fc9 172800 ns com. b.gtld-servers.net. @40000000569e21d82b23c514 rr c0e44fc9 172800 ns com. g.gtld-servers.net. @40000000569e21d82b23c8fc rr c0e44fc9 172800 ns com. h.gtld-servers.net. @40000000569e21d82b23e83c rr c0e44fc9 172800 ns com. m.gtld-servers.net. @40000000569e21d82b23ec24 rr c0e44fc9 172800 ns com. l.gtld-servers.net. @40000000569e21d82b23f00c rr c0e44fc9 172800 ns com. k.gtld-servers.net. @40000000569e21d82b23f00c rr c0e44fc9 172800 ns com. f.gtld-servers.net. @40000000569e21d82b23f3f4 rr c0e44fc9 172800 ns com. i.gtld-servers.net. @40000000569e21d82b23f7dc rr c0e44fc9 172800 28 a.gtld-servers.net. 20010503a83e00000000000000020030 @40000000569e21d82b24077c stats 1 1392 1 0 @40000000569e21d82b24077c cached 1 e.gtld-servers.net. @40000000569e21d82b240b64 cached 1 c.gtld-servers.net. @40000000569e21d82b240b64 cached 1 j.gtld-servers.net. @40000000569e21d82b240f4c cached 1 a.gtld-servers.net. @40000000569e21d82b240f4c cached 1 d.gtld-servers.net. @40000000569e21d82b241334 cached 1 b.gtld-servers.net. @40000000569e21d82b241334 cached 1 g.gtld-servers.net. @40000000569e21d82b2422d4 cached 1 h.gtld-servers.net. @40000000569e21d82b2422d4 cached 1 m.gtld-servers.net. @40000000569e21d82b2426bc cached 1 l.gtld-servers.net. @40000000569e21d82b2426bc cached 1 k.gtld-servers.net. @40000000569e21d82b242aa4 cached 1 f.gtld-servers.net. @40000000569e21d82b242aa4 cached 1 i.gtld-servers.net. <<com NSをキャッシュ; *.gtld-servers.net IPもキャッシュ? まずい>> com NS である *.gtld-servers.net には glueはつかない。additionalは捨てるのが正しい。 ただし、*.gtld-servers.net A は net NS のものがキャッシュに残っているので、 dnscache はそれを使うのだろうと想像していた。（前野） <<com NSにav1.nstld.com A を問い合わせる>> @40000000569e21d82b242aa4 tx 1 1 av1.nstld.com. com. c029a21e c005061e c01a5c1e c00c5e1e c01f501e c034b21e c036701e c0210e1e c037531e c0304f1e c02a5d1e c02bac1e c023331e @40000000569e21d835c7cca4 rr c029a21e 172800 1 av1.nstld.com. c02ab11e @40000000569e21d835c7d08c rr c029a21e 172800 1 av2.nstld.com. c02ab21e @40000000569e21d835c7d474 rr c029a21e 172800 1 av3.nstld.com. c052851e @40000000569e21d835c7d85c rr c029a21e 172800 1 av4.nstld.com. c052861e @40000000569e21d835c7d85c rr c029a21e 172800 ns nstld.com. av1.nstld.com. @40000000569e21d835c7dc44 rr c029a21e 172800 ns nstld.com. av2.nstld.com. @40000000569e21d835c7e02c rr c029a21e 172800 ns nstld.com. av3.nstld.com. @40000000569e21d835c7e02c rr c029a21e 172800 ns nstld.com. av4.nstld.com. @40000000569e21d835c816dc rr c029a21e 172800 28 av1.nstld.com. 20010500012400000000000000000030 @40000000569e21d835c81ac4 rr c029a21e 172800 28 av2.nstld.com. 20010500012500000000000000000030 @40000000569e21d835c81ac4 rr c029a21e 172800 28 av3.nstld.com. 20010500012600000000000000000030 @40000000569e21d835c81eac rr c029a21e 172800 28 av4.nstld.com. 20010500012700000000000000000030 @40000000569e21d835c82294 stats 1 1869 1 0 @40000000569e21d835c82294 cached 1 av1.nstld.com. @40000000569e21d835c8361c cached 1 av2.nstld.com. @40000000569e21d835c83a04 cached 1 av3.nstld.com. @40000000569e21d835c83a04 cached 1 av4.nstld.com. <<これで av1.nstld.comを問い合わせできる。>> @40000000569e21d835c83dec tx 1 1 av1.nstld.com. nstld.com. c02ab11e c052851e c02ab21e c052861e @40000000569e21d90614e474 rr c02ab11e 300 1 av1.nstld.com. c02ab11e @40000000569e21d90614e85c stats 1 1869 1 0 @40000000569e21d90614ec44 cached 1 av2.nstld.com. @40000000569e21d90614ec44 cached 1 av3.nstld.com. @40000000569e21d90614f02c cached 1 av4.nstld.com. @40000000569e21d90614f02c tx 0 1 a.gtld-servers.net. gtld-servers.net. c052851e c052861e c02ab21e c02ab11e @40000000569e21d9068bc224 rr c052851e 86400 1 a.gtld-servers.net. c005061e @40000000569e21d9068bc60c stats 1 1869 1 0 @40000000569e21d9068bc9f4 sent 1 52