1. DNS Summer Days 2014 2014-06-26 DNS

2. : @ttkzw : 24365 MSP DNS 19972006 BIND4, BIND8, djbdns, BIND9 NSD, Unbound Unbound Unbound/NSD DNS 2 2014/06/26DNS Summer Days 2014 - DNS 3. DNS DNS DNS 3 2014/06/26DNS Summer Days 2014 - DNS 4. DNS EDNS0, DNS UPDATE, DNSSEC 2014/06/26DNS Summer Days 2014 - DNS 4 5. IP 5 2014/06/26DNS Summer Days 2014 - DNS 6. ? ? 6 2014/06/26DNS Summer Days 2014 - DNS 7. 1 7 2014/06/26DNS Summer Days 2014 - DNS 8. IP TCP/IP IP IPv4 192.0.2.1 IPv6 2001:db8:dead:beef:123:4567:89ab:cdef IPv4 192.0.2.1 IPv6 2001:db8:dead:beef: 123:4567:89ab:cdee IPv4 192.0.2.4 IPv6 2001:db8:dead:beef: 123:4567:89ab:cdef 8 2014/06/26DNS Summer Days 2014 - DNS 9. IP IPv6 IPv4 192.0.2.1 IPv6 2001:db8:dead:beef: 123:4567:89ab:cdee IPv4 192.0.2.4 IPv6 2001:db8:dead:beef: 123:4567:89ab:cdef 9 2014/06/26DNS Summer Days 2014 - DNS 10. www.example.jp mars IP www.example.jp (192.0.2.1) mars (192.0.2.4) 10 2014/06/26DNS Summer Days 2014 - DNS 11. IP mars mars IP mars IP192.0.2.4 IP192.0.2.4 11 2014/06/26DNS Summer Days 2014 - DNS IP IP 12. IP OS OS IP 12 2014/06/26DNS Summer Days 2014 - DNS 13. hosts /etc/hosts C:WindowsSystem32driversetchosts DNS 13 2014/06/26DNS Summer Days 2014 - DNS 14. hosts mars mars IP hosts DNS mars IP 192.0.2.4 IP192.0.2.4 14 2014/06/26DNS Summer Days 2014 - DNS 15. IP hostsDNS IP 15 2014/06/26DNS Summer Days 2014 - DNS 16. 16 2014/06/26DNS Summer Days 2014 - DNS 17. DNSDomain Name System www.example.jp 17 2014/06/26DNS Summer Days 2014 - DNS com jp coexampleexample ns www 18. DNS IP IP 18 2014/06/26DNS Summer Days 2014 - DNS 19. DNS SOA NS IPv4A IPv6AAAA IPPTR CNAME TXT 19 2014/06/26DNS Summer Days 2014 - DNS 20. DNS (Stub Resolver) *1 (Full-Service Resolver) *2 Recursive Server *3, Recursive Name Server *2 DNS DNS (Authoritative Name Server) *1 DNS DNS 20 2014/06/26DNS Summer Days 2014 - DNS *1 RFC 1034, RFC 1035 *2 RFC 1123 *3 RFC 1034 21. DNS www.example.jp IP www.example.jp IP192.0.2.4 jp example.jp 21 2014/06/26DNS Summer Days 2014 - DNS DNS DNS 22. DNS DNS DNSDNS DNS 22 2014/06/26DNS Summer Days 2014 - DNS 23. 23 2014/06/26DNS Summer Days 2014 - DNS 24. DNS com jp coexampleexample ns www example.jp. IN NS ns.example.jp. example.jp. IN SOA ns.exampele.jp. .. ns.example.jp. IN A 192.0.2.1 24 2014/06/26DNS Summer Days 2014 - DNS 25. : DNS RFC RFC 1034 / STD 13 DOMAIN NAMES - CONCEPTS AND FACILITIES RFC 1982 / PS Serial Number Arithmetic RFC 1035 / STD 13 DOMAIN NAMES - IMPLEMENTATION AND SPECIFICATION RFC 1123 / STD 3 Requirements for Internet Hosts -- Application and Support RFC 3425 / PS Obsoleting IQUERY RFC 2308 / PS Negative Caching of DNS Queries (DNS NCACHE) RFC 5452 / PS Measures for Making DNS More Resilient against Forged Answers RFC 2181 / PS Clarifications to the DNS Specification RFC 5966 / PS DNS Transport over TCP - Implementation Requirements RFC 5936 / PS DNS Zone Transfer Protocol (AXFR) RFC 4343 / PS Domain Name System (DNS) Case Insensitivity Clarification 25 2014/06/26DNS Summer Days 2014 - DNS RFC 6891 / STD 75 Extension Mechanisms for DNS (EDNS(0)) RFC 4592 / PS The Role of Wildcards in the Domain Name System RFC 1996 / PS A Mechanism for Prompt Notification of Zone Changes (DNS NOTIFY) RFC 1995 / PS Incremental Zone Transfer in DNS 26. 26 2014/06/26DNS Summer Days 2014 - DNS 27. DNS com jp coexampleexample ns www example.jp. IN NS ns.example.jp. example.jp. IN SOA ns.exampele.jp. .. ns.example.jp. IN A 192.0.2.1 27 2014/06/26DNS Summer Days 2014 - DNS 28. 28 2014/06/26DNS Summer Days 2014 - DNS com jp coexampleexample ns www 29. null 0 2014/06/26DNS Summer Days 2014 - DNS 29 com jp coexampleexample ns www "com" 30. ) "www", "example", "jp", "" 2014/06/26DNS Summer Days 2014 - DNS 30 com jp coexampleexample ns www 31. "www"16 3 77 77 77 2014/06/26DNS Summer Days 2014 - DNS 31 32. null 0 www.example.jp. 3 77 77 77 7 65 78 61 6d 70 6c 65 2 6a 70 0 2014/06/26DNS Summer Days 2014 - DNS 32 com jp coexampleexample ns www 33. "." www.example.jp. www.example.jp." " 2014/06/26DNS Summer Days 2014 - DNS 33 com jp coexampleexample ns www 34. "www.example.jp." "www" "example.jp." 2014/06/26DNS Summer Days 2014 - DNS 34 com jp coexampleexample ns www www.example.jp. www 35. DNS example.jp. IN NS ns.example.jp. $ORIGIN example.jp. www IN A 192.0.2.4 35 2014/06/26DNS Summer Days 2014 - DNS 36. "." "." $ORIGIN example.jp. www IN NS ns.example.jp $ORIGIN example.jp. www.example.jp. IN NS ns.example.jp.example.jp. 36 2014/06/26DNS Summer Days 2014 - DNS 37. digDNS dig www.example.jp. A 37 2014/06/26DNS Summer Days 2014 - DNS 38. ping $ORIGIN example.jp. www IN A 192.0.2.4 38 2014/06/26DNS Summer Days 2014 - DNS 39. /etc/resolv.conf"domain""search" domain example.jp nameserver 192.0.2.1 nameserver 192.0.2.2 39 2014/06/26DNS Summer Days 2014 - DNS 40. "." "example.jp""example.jp." "example.jp" FQDN 40 2014/06/26DNS Summer Days 2014 - DNS 41. (SLD) (TLD) TLDSLD 41 2014/06/26DNS Summer Days 2014 - DNS com jp coexampleexample ns www netorg kr 42. (FQDN) Fully Qualified Domain Name FQDN : "www.example.jp" 42 2014/06/26DNS Summer Days 2014 - DNS com jp coexampleexample ns www 43. (FQDN) FQDN / FQDN "." 43 2014/06/26DNS Summer Days 2014 - DNS 44. com jp "jp" co.jp example.jp www.example.jp 44 2014/06/26DNS Summer Days 2014 - DNS com jp coexampleexample ns www 45. "www.example.jp" example.jp jp 45 2014/06/26DNS Summer Days 2014 - DNS com jp coexampleexample ns www 46. RFC 952, RFC 1123 46 2014/06/26DNS Summer Days 2014 - DNS RFC 952 DOD INTERNET HOST TABLE SPECIFICATION RFC 1123 Requirements for Internet Hosts -- Application and Support "2.1 Host Names and Numbers" 47. 063 0 0 "." 47 2014/06/26DNS Summer Days 2014 - DNS 48. 8bit "_" SRV _ldap._tcp.example.com. DKIM foo.bar._domainkey.example.com. 48 2014/06/26DNS Summer Days 2014 - DNS RFC 2782 A DNS RR for specifying the location of services (DNS SRV) RFC 6376 DomainKeys Identified Mail (DKIM) Signatures 49. 255 FQDN 253 RFC 1123 63 MUST 255SHOULD 49 2014/06/26DNS Summer Days 2014 - DNS RFC 1123 Requirements for Internet Hosts -- Application and Support "2.1 Host Names and Numbers" 50. 2014/06/26DNS Summer Days 2014 - DNS 50 RFC 4343 Domain Name System (DNS) Case Insensitivity Clarification 51. TLDSLD FQDN 51 2014/06/26DNS Summer Days 2014 - DNS 52. 52 2014/06/26DNS Summer Days 2014 - DNS 53. DNS com jp coexampleexample ns www example.jp. IN NS ns.example.jp. example.jp. IN SOA ns.exampele.jp. .. ns.example.jp. IN A 192.0.2.1 53 2014/06/26DNS Summer Days 2014 - DNS 54. "example.jp"example.jp 54 2014/06/26DNS Summer Days 2014 - DNS com jp coexampleexample ns www (zone apex) 55. authority authoritative name server 55 2014/06/26DNS Summer Days 2014 - DNS com jp coexampleexample ns www example.jp. example.jp. ns.example.jp. example.jp. 56. "example.jp" "sub.example.jp" 56 2014/06/26DNS Summer Days 2014 - DNS example.jp. sub.example.jp. com jp coexampleexample ns wwwsub wwwns 57. 57 2014/06/26DNS Summer Days 2014 - DNS example.jp. sub.example.jp. example.jp. sub.example.jp. com jp coexampleexample ns wwwsub wwwns 58. zone cut 58 2014/06/26DNS Summer Days 2014 - DNS (zone cut) example.jp. sub.example.jp. com jp coexampleexample ns wwwsub wwwns 59. zone cut NS RRsglueRRs NS AAAAA SOANS AAAAA 59 2014/06/26DNS Summer Days 2014 - DNS 60. RRs example.jp. sub.example.jp. IN NS ns.sub.example.jp. ns.sub.example.jp. IN A 192.0.2.4 sub.example.jp. $ORIGIN sub.example.jp. @ IN SOA ns.sub.example.jp. ( hostmaster.sub.example.jp. 2013071901 3600 900 604800 900 ) @ IN NS ns.sub.example.jp. ns IN A 192.0.2.4 60 2014/06/26DNS Summer Days 2014 - DNS RR 61. DNS TLD TLDSLD TLD,SLD 61 2014/06/26DNS Summer Days 2014 - DNS 62. IANAICANN 62 2014/06/26DNS Summer Days 2014 - DNS 63. IANA IANA Internet Assigned Numbers Authority "" https://www.iana.org/ DNS DNSIPAS INTARPA 63 2014/06/26DNS Summer Days 2014 - DNS 64. IANAICANN IANAARPANET 1998ICANNInternet Corporation for Assigned Names and Numbers" " IANAICANNIANA ICANN 64 2014/06/26DNS Summer Days 2014 - DNS 65. ICANN 65 2014/06/26DNS Summer Days 2014 - DNS 66. 66 2014/06/26DNS Summer Days 2014 - DNS 67. 67 2014/06/26DNS Summer Days 2014 - DNS 68. ICANN/IANA 68 2014/06/26DNS Summer Days 2014 - DNS com jp co exampleexample ns www org www 69. generic top-level domaingTLD country-code top-level domainccTLD 69 2014/06/26DNS Summer Days 2014 - DNS 70. (gTLD) ARPA BIZ COM INFO NAME NET ORG PRO 70 2014/06/26DNS Summer Days 2014 - DNS 71. (gTLD) AERO ASIA CAT COOP EDU 4 GOV INT JOBS MIL MOBI MUSEUM TEL TRAVEL XXX 71 2014/06/26DNS Summer Days 2014 - DNS 72. (ccTLD) BR CA CN DE EU FR IN IT JP KR RU UK US 72 2014/06/26DNS Summer Days 2014 - DNS 73. (ccTLD) , (CN) (HK) , (TW) (KR) (TH) , !#, , , , , (IN) , (SG) (RU) (LK) (UA) (SA) 73 2014/06/26DNS Summer Days 2014 - DNS 74. test DNS example invalid localhost local (RFC 6762) 74 2014/06/26DNS Summer Days 2014 - DNS RFC 2606 Reserved Top Level DNS Names RFC 6761 Special-Use Domain Names RFC 6762 Multicast DNS 75. ARPA "ARPA" "ARPA""ARPANET" HOSTS.TXTDNSARPANET IP "IN-ADDR.ARPA" 75 2014/06/26DNS Summer Days 2014 - DNS 76. ARPA IN-ADDR.ARPA, IP6.ARPA,,, "ARPA""Address and Routing Parameter Area" (RFC 3172) 76 2014/06/26DNS Summer Days 2014 - DNS RFC 3172 Management Guidelines & Operational Requirements for the Address and Routing Parameter Area Domain ("arpa") 77. ARPA RFC e164.arpa E.164 RFC 6116 in-addr-servers.arpa in-addr.arpa RFC 5855 in-addr.arpa IPv4 RFC 1035 ip6-servers.arpa ip6.arpa RFC 5855 ip6.arpa IPv6 RFC 3152 RFC 3596 ipv4only.arpa DNS64 RFC 7050 iris.arpa RFC 4698 uri.arpa URI RFC 3405 urn.arpa URN RFC 3405 2014/06/26DNS Summer Days 2014 - DNS 77 RFC 3152 Delegation of IP6.ARPA RFC 3596 DNS Extensions to Support IP Version 6 RFC 5855 Nameservers for IPv4 and IPv6 Reverse Zones 78. ARPA 78 2014/06/26DNS Summer Days 2014 - DNS 79. 79 2014/06/26DNS Summer Days 2014 - DNS 80. DNS com jp coexampleexample ns www example.jp. IN NS ns.example.jp. example.jp. IN SOA ns.exampele.jp. .. ns.example.jp. IN A 192.0.2.1 80 2014/06/26DNS Summer Days 2014 - DNS 81. IP RR RRset 81 2014/06/26DNS Summer Days 2014 - DNS 82. OWNER TTL CLASS TYPE RDATA www.example.jp. 3600 IN A 192.0.2.1 82 2014/06/26DNS Summer Days 2014 - DNS 83. ORNER OWNER TTL CLASS TYPE RDATA www.example.jp. 3600 IN A 192.0.2.1 83 2014/06/26DNS Summer Days 2014 - DNS com jp coexampleexample ns www 84. TTL OWNER TTL CLASS TYPE RDATA www.example.jp. 3600 IN A 192.0.2.1 32 TTLRR : 0 0 : 2147483647 (2^31 1) 1TTL0 84 2014/06/26DNS Summer Days 2014 - DNS RFC 2181 Clarifications to the DNS Specification - "8. Time to Live (TTL)" 85. CLASS OWNER TTL CLASS TYPE RDATA www.example.jp. 3600 IN A 192.0.2.1 16 85 2014/06/26DNS Summer Days 2014 - DNS IN 1 Internet CH 3 Chaos HS 4 Hesiod $ dig version.bind. TXT CH 86. TYPE OWNER TTL CLASS TYPE RDATA www.example.jp. 3600 IN A 192.0.2.1 16 A, CNAME, MX, NS, PTR, SOA, TXT 86 2014/06/26DNS Summer Days 2014 - DNS 87. A 1 IPv4IP NS 2 CNAME 5 SOA 6 PTR 12 IP MX 15 TXT 16 AAAA 28 IPv6IP 2014/06/26DNS Summer Days 2014 - DNS 87 88. RDATA OWNER TTL CLASS TYPE RDATA www.example.jp. 3600 IN A 192.0.2.1 88 2014/06/26DNS Summer Days 2014 - DNS 89. A 1 IPv4IP NS 2 CNAME 5 SOA 6 PTR 12 IP MX 15 TXT 16 AAAA 28 IPv6IP 2014/06/26DNS Summer Days 2014 - DNS 89 90. SOA (Start Of Authority) RR 90 2014/06/26DNS Summer Days 2014 - DNS 91. SOA OWNER TTL IN SOA MNAME RNAME ( SERIAL REFRESH RETRY EXPIRE MINIMUM ) OWNER 91 2014/06/26DNS Summer Days 2014 - DNS 92. SOA MNAME NOTIFY DNS UPDATE RFC 2181 Clarifications to the DNS Specification "7.3. The SOA.MNAME field" SOAMNAME 92 2014/06/26DNS Summer Days 2014 - DNS 93. SOA RNAME "@""." "foo@example.com""foo.example.com." 93 2014/06/26DNS Summer Days 2014 - DNS 94. SOA SERIAL 32 sequence space arithmetic (RFC 1982) REFRESH RETRY 94 2014/06/26DNS Summer Days 2014 - DNS RFC 1982 Serial Number Arithmetic 95. SOA EXPIRE MINIMUM RR TTL RFC 2308 TTL 95 2014/06/26DNS Summer Days 2014 - DNS RFC 2308 Negative Caching of DNS Queries (DNS NCACHE) 96. SOA example.jp. IN SOA ns.example.jp. hostmaster.example.jp. ( 2013071901 ;serial 3600 ;refresh 600 ;retry 604800 ;expire 900 ) ;minimum "ns.example.jp." "hostmaster@example.jp" 96 2014/06/26DNS Summer Days 2014 - DNS TTL "86400" 97. NS (Name Server) NS CNAME 97 2014/06/26DNS Summer Days 2014 - DNS RFC 2181 Clarifications to the DNS Specification "10.3. MX and NS records" 98. NS OWNER TTL IN NS NSDNAME NSDNAME example.jp. 86400 IN NS ns.example.jp. "example.jp." "ns.example.jp." 98 2014/06/26DNS Summer Days 2014 - DNS 99. A (Address) IPv4IP 99 2014/06/26DNS Summer Days 2014 - DNS 100. A OWNER TTL IN A ADDRESS ADDRESS IPv4IP10 www.example.jp. 86400 IN A 192.0.2.1 100 2014/06/26DNS Summer Days 2014 - DNS 101. AAAA IPv6IP 101 2014/06/26DNS Summer Days 2014 - DNS RFC 3596 DNS Extensions to Support IP Version 6 102. AAAA OWNER TTL IN AAAA ADDRESS ADDRESS IPv6IP www.example.jp. 86400 IN AAAA 2001:db8:dead:beef::1 www.example.jp.IPv6 "2001:db8:dead:beef::1" 102 2014/06/26DNS Summer Days 2014 - DNS 103. CNAME (Canonical Name) CNAMENSMX 103 2014/06/26DNS Summer Days 2014 - DNS RFC 2181Clarifications to the DNS Specification "10.3. MX and NS records" 104. CNAME OWNER TTL IN CNAME CNAME CNAME foo.example.jp. IN A 192.0.2.1 www.example.jp. IN CNAME foo.example.jp. "foo.example.jp." "www.example.jp." 104 2014/06/26DNS Summer Days 2014 - DNS 105. PTR (Pointer) IP IP 105 2014/06/26DNS Summer Days 2014 - DNS 106. PTR (Pointer)IP IPv4IPin- addr.arpa. 192.0.2.1 1.2.0.192.in-addr.arpa. IPv6IP ip6.arap. 2001:db8:dead:beef::1 1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.f.e.e.b.d.a.e.d. 8.b.d.0.1.0.0.2.ip6.arpa. 106 2014/06/26DNS Summer Days 2014 - DNS 107. PTR OWNER TTL IN PTR PTRDNAME OWNER in-addr.arpa.ip6.arpa.IP PTRDNAME IP 107 2014/06/26DNS Summer Days 2014 - DNS 108. PTR IPv4 1.2.0.192.in-addr.arpa. IN PTR www.example.jp. IP"192.0.2.1" "www.example.jp." IPv6 1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.f.e.e.b.d.a.e.d. 8.b.d.0.1.0.0.2.ip6.arpa. IN PTR www.example.jp. IPv6"2001:db8:dead:beef::1" "www.example.jp." 108 2014/06/26DNS Summer Days 2014 - DNS 109. PTR (Pointer) PTRPTRDNAMECNAME : IPPTR : IPPTR 109 2014/06/26DNS Summer Days 2014 - DNS RFC 2181Clarifications to the DNS Specification "10.2. PTR records" 110. MX (Mail Exchanger) MXEXCHANGECNAME 110 2014/06/26DNS Summer Days 2014 - DNS RFC 2181Clarifications to the DNS Specification "10.3. MX and NS records" 111. MX OWNER TTL IN MX PREFERENCE EXCHANGE OWNER PREFERENCE EXCHANGE 111 2014/06/26DNS Summer Days 2014 - DNS 112. MX example.jp. IN MX 10 mx1.example.jp. IN MX 20 mx2.example.jp. example.jp. mx1.example.jp.mx2.example.jp. mx1.example.jp. 112 2014/06/26DNS Summer Days 2014 - DNS 113. TXT (Text) SPF DKIM DNSBL 113 2014/06/26DNS Summer Days 2014 - DNS 114. TXT OWNER TTL IN TXT TXT-DATA TXT-DATA example.jp. IN TXT "Hello, World" example.jp. IN TXT "v=spf1 mx -all" 114 2014/06/26DNS Summer Days 2014 - DNS 115. SOA, NS, A, AAAA, CNAME, PTR, MX, TXT 115 2014/06/26DNS Summer Days 2014 - DNS 116. 116 2014/06/26DNS Summer Days 2014 - DNS 117. DNS com jp coexampleexample ns www example.jp. IN NS ns.example.jp. example.jp. IN SOA ns.exampele.jp. .. ns.example.jp. IN A 192.0.2.1 117 2014/06/26DNS Summer Days 2014 - DNS 118. 2014/06/26DNS Summer Days 2014 - DNS 118 119. $ORIGIN example.jp. $TTL 86400 @ IN SOA ns.example.jp. hostmaster.example.jp. ( 2011061801 ; Serial 3600 ; Refresh 900 ; Retry 604800 ; Expire 3600 ) ; Minimum IN NS ns.example.jp. IN MX 10 mx.example.jp. IN A 192.0.2.2 ns IN A 192.0.2.1 www IN A 192.0.2.2 mx IN A 192.0.2.3 119 2014/06/26DNS Summer Days 2014 - DNS 120. ";" 2014/06/26DNS Summer Days 2014 - DNS 120 121. RR1 example.com. 172800 IN NS a.iana-servers.net. example.com. 3600 IN SOA sns.dns.icann.org. ( noc.dns.icann.org. 2014051879 ; serial 7200 ; refresh (2 hours) 3600 ; retry (1 hour) 1209600 ; expire (2 weeks) 3600 ; minimum (1 hour) ) 2014/06/26DNS Summer Days 2014 - DNS 121 122. RR example.com. 172800 IN NS a.iana-servers.net. RR example.com. 172800 IN NS a.iana-servers.net. 172800 IN NS b.iana-servers.net. 2014/06/26DNS Summer Days 2014 - DNS 122 123. $ORIGIN 2 $ORIGIN $ORIGIN example.com. www 86400 IN A 192.0.2.2 $ORIGIN www.example.com. 86400 IN A 192.0.2.2 2014/06/26DNS Summer Days 2014 - DNS 123 124. "@" example.com. example.com. 172800 IN NS a.iana-servers.net. @ 172800 IN NS a.iana-servers.net. 2014/06/26DNS Summer Days 2014 - DNS 124 125. $TTL TTL TTL TTL TTL$TTL 2TTL $TTL 86400 www1.example.com. A 192.0.2.2 www2.example.com. 86400 A 192.0.2.3 2014/06/26DNS Summer Days 2014 - DNS 125 RFC 2308 Negative Caching of DNS Queries (DNS NCACHE) "4 - SOA Minimum Field" 126. "IN" "IN" 3 $TTL 86400 www 86400 IN A 192.0.2.2 www IN A 192.0.2.2 www A 192.0.2.2 $INCLUDE 2014/06/26DNS Summer Days 2014 - DNS 126 127. $ORIGIN example.jp. $TTL 86400 @ IN SOA ns.example.jp. hostmaster.example.jp. ( 2011061801 ; Serial 3600 ; Refresh 900 ; Retry 604800 ; Expire 3600 ) ; Minimum IN NS ns.example.jp. IN MX 10 mx.example.jp. IN A 192.0.2.2 ns IN A 192.0.2.1 www IN A 192.0.2.2 mx IN A 192.0.2.3 127 2014/06/26DNS Summer Days 2014 - DNS 128. 128 2014/06/26DNS Summer Days 2014 - DNS 129. 2014/06/26DNS Summer Days 2014 - DNS 129 130. DNS com jp coexampleexample ns www example.jp. IN NS ns.example.jp. example.jp. IN SOA ns.exampele.jp. .. ns.example.jp. IN A 192.0.2.1 130 2014/06/26DNS Summer Days 2014 - DNS 131. DNS DNSDNS DNS UDP512 TCP512 EDNS0UDP512 2014/06/26DNS Summer Days 2014 - DNS 131 EDNS0DNS 132. 2014/06/26DNS Summer Days 2014 - DNS 132 $ dig @ns.example.jp. example.jp. +norec ;; ->>HEADERHEADERHEADER