En ocasiones nos surge la duda sobre si tenemos la verisón buena del root cache, la mejor maneraasegurarnos el tiro es preguntarle a un root-server por la lista completa:
-bash-3.00# dig @a.root-servers.net. . ns
; < <>> DiG 9.2.4 < <>> @a.root-servers.net. . ns
; (2 servers found)
;; global options: printcmd
;; Got answer:
;; ->>HEADER< <- opcode: QUERY, status: NOERROR, id: 40901 ;; flags: qr aa rd; QUERY: 1, ANSWER: 13, AUTHORITY: 0, ADDITIONAL: 14 ;; QUESTION SECTION: ;. IN NS ;; ANSWER SECTION: . 518400 IN NS I.ROOT-SERVERS.NET. . 518400 IN NS J.ROOT-SERVERS.NET. . 518400 IN NS K.ROOT-SERVERS.NET. . 518400 IN NS L.ROOT-SERVERS.NET. . 518400 IN NS M.ROOT-SERVERS.NET. . 518400 IN NS A.ROOT-SERVERS.NET. . 518400 IN NS B.ROOT-SERVERS.NET. . 518400 IN NS C.ROOT-SERVERS.NET. . 518400 IN NS D.ROOT-SERVERS.NET. . 518400 IN NS E.ROOT-SERVERS.NET. . 518400 IN NS F.ROOT-SERVERS.NET. . 518400 IN NS G.ROOT-SERVERS.NET. . 518400 IN NS H.ROOT-SERVERS.NET. ;; ADDITIONAL SECTION: A.ROOT-SERVERS.NET. 3600000 IN A 198.41.0.4 A.ROOT-SERVERS.NET. 3600000 IN AAAA 2001:503:ba3e::2:30 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 F.ROOT-SERVERS.NET. 3600000 IN AAAA 2001:500:2f::f G.ROOT-SERVERS.NET. 3600000 IN A 192.112.36.4 H.ROOT-SERVERS.NET. 3600000 IN A 128.63.2.53 H.ROOT-SERVERS.NET. 3600000 IN AAAA 2001:500:1::803f:235 I.ROOT-SERVERS.NET. 3600000 IN A 192.36.148.17 J.ROOT-SERVERS.NET. 3600000 IN A 192.58.128.30 J.ROOT-SERVERS.NET. 3600000 IN AAAA 2001:503:c27::2:30 ;; Query time: 122 msec ;; SERVER: 198.41.0.4#53(198.41.0.4) ;; WHEN: Mon Jun 2 10:03:11 2008 ;; MSG SIZE rcvd: 500 -bash-3.00#
si queremos usarlo directamente pues hacemos un simple:
dig @a.root-servers.net. . ns >root.cache