½Ð°Ý§Ú¦p¦ó±oª¾, ¦Û¤v©Ò¥Îªººô¯¸, ¦³¨S¦³§¹¾ãªº¥¿¤Ï¸Ñ DNS database µn¿ý ?
Q: §Ú¥u¬O¤@¯ëªº¨Ï¥ÎªÌ, ¦³þ¨Ç¤èªk, ¥i¥HÅý§Ú½T©w, ¦Û¤v©Ò¨Ï¥Îªº¯¸»Oªººô§}
( IP addr.) ¦³¨S¦³§¹¾ãªº¥¿¤Ï¸Ñ DNS database µn¿ý ?
A: ¦³³\¦h§@ªk, ¥i¥HÀ°¦£¸Ñµª, ³o¤@Ãþªº°ÝÃD.
³Ì²³æªº¤èªk, ¤]³\¬O½Ð±Ð¸Ó³æ¦ìºô¯¸ªººÞ²z¤Hû.
-- ¤£¹L, ¦b°ê¤º, ¥Ø«e¦³«Ü¦h³æ¦ì, ³sºÞ²zªÌ¦Û¤v¤]·d¤£²M·¡, ³o¨ÇªF¦è :-(
¦pªG, §A¦³ Unix site ªº shell account. ¨º»ò, §A¦³¾÷·|¨Ï¥Î telnet,
³s¤W ¬Y remote site ¤§«á, §A¥i¥H¨Ï¥Î last µ{¦¡. ¨ÃÆ[¹î¿é¥Xµ²ªG.
% last | more
³q±`, °£«D§A©Ò¥Î¯¸»O, ÁõÄݪººô°ì¦³³]©w°ÝÃD. §_«h, ¥un¸Óºô°ì¦³§¹¾ã
ªº¥¿¤Ï¸Ñµù¥UªÌ, remote site «K¥i¥H¸g¥Ñ revserse/forward DNS ¬d¸ß,
±o¨ì§A±q¨º¤@¯¸¤W¨Óªº¸ê°T. ¦]¦¹, §A¥i¥H¬Ý¨ì last |more ªº¿é¥X, Åã¥Ü
¥X¨Óªºªº¬O^¤å¦WºÙ.
¥t¤@¤è±, ¦pªG¥u¬Ý¨ì IP addr. ªÌ, ³q±`´N¬O¤Ï¸Ñµù¥U¦³°ÝÃD.
³Æµù:
-- ¦]¬°, ¾ã®M DNS ¬O¶¥¼h¦¡¤À´²¨t²Î, ¦]¦¹´ú¸Õ®É, °£¤F¨Ï¥Î¥»³æ¦ìªº
DNS server ¥~, ¤@©wn¦A¸Õ¨ä¥¦³æ¦ìªº DNS server. ¤~¥i¥H, ½T»{
¶Q³æ¦ìªº DNS server ³]©w¬O§_¥¿½T. ¨Ò¦p, ¨ä¥¦³æ¦ìªººô¤Í, ¥i¥H
³z¹L DNS ¬d¸ßµ{¦¡, ¦p nslookup, dig µ¥, ±N DNS query Âà¨ì NCTU
ªº DNS server ¨Ó´ú¸Õ. ( E.g, ns.NCTU.edu.tw, ns1.NCTU.edu.tw )
³oùØn±j½Õ, ¦³³\¦h³æ¦ì, ¨Ã¨S¦³½T¹ê§¹¦¨ DNS server ªº¤W¤U´å°t¦Xµn°O.
¬Æ¦Ü¥X²{, ©ú©ú¶Q³æ¦ì¦³¦V¤W¼h Domain Zone §¹¦¨, forward/reverse DNS
µù¥Uµn°O, ¥»³æ¦ìªº³]©w¬Ý¨Ó¤]¨S¦³¿ù. ¦ý«o¤´µM, µLªkÅý forward and/or
reverse DNS ¥¿±`¹B§@; °ÝÃDªº®Ú·½, ´N¦b©ó, §Aªº¤W¤@¼h domain zone
ªººÞ²zªÌ, ®Ú¥»´N¨S¦³¦b§ó¤W¤@¼hªº Domain zone §¹¦¨µù¥Uµn¿ý.
¦]¦¹, ¥Ñ root DNS servers, ®Ú¥»¨S¿ìªk, ¨«(«ü¬£)¨ì¶Q³æ¦ìªº³]©w.
©Ò¥H, ¤~·|¥X²{, ¤´µMµLªk¥¿±`¹B§@ªº±¡ªp.
-- ·íµM, ¦³®ÉÔ¸I¤Wºô¸ôÂ_½u, or ¸Ó³æ¦ìªº DNS server crashed, ¤]¦³
¥i¯à¥X²{, ¬d¤£¨ì remote site forward/reverse DNS ªº¸ê®Æªº±¡ªp.
¥¿±`±¡§Î¤U, ¬O¤£·|³o¼Ëªº.
------------------------------------------------------------------------
ftp% last |more
cschen pts/24 NCTU.edu.tw Sun May 11 12:56 still logged in
ftp ftp 203.98.11.203 Sun May 11 12:56 - 12:56 (00:00)
ftp ftp 168.95.10.47 Sun May 11 12:56 - 12:56 (00:00)
ftp ftp dialup13.nhctc.e Sun May 11 12:55 - 12:55 (00:00)
...
[delete]
------------------------------------------------------------------------
§A¤]¥i¥H¥h¸Õ¸Õ°ê¥~¬Û·íµÛ¦Wªº FTP ¯¸, ¦p ftp.uu.net ¤§Ãþ. ¦pªG, ¸Ó¯¸µ¹§A
³s½u¨Ï¥ÎÅv (¦b¨S¦³¦]¶W¸ü¦Ó©Úµ´§Aªº³s½u), ´Nªí¥Ü§A©Ò¨Ï¥Îªº¯¸¥x, ¦³§¹¾ã
ªº forward/reverse DNS database µn¿ý.
PS. ¦P¼Ëªº±¡ªp, §A¥i¥H¸Õ ftp.cis.nctu.edu.tw.
¨Ï¥Î News Reader, ¹Á¸Õ³s news.cis.nctu.edu.tw.
- or, ¥Î telnet ¤]¥i¥H¸Õ.
% telnet news.cis.nctu.edu.tw 119
³q±`¦pªG, ¥X²{Ãþ¦ü¦p¤Uªº¤ÏÀ³, ´N¥i¯à¬O forward/reverse DNS µn¿ý¤£¥þ.
-----------------------------------------------------------
502 You have no permission to talk. Goodbye.
Connection closed by foreign host.
¨Ï¥Î news reader µ¥³nÅé, ¦b "tw.bbs.test" ³oÓ newsgroups, ±i¶K¤@½g
´ú¸Õ articles, ¥un¦¨¥\°e¤W NetNews server, µM«á§A¥i¥HÀ˵ø¸Ó article
ªºÀÉÀY (headers). ¨ä¤¤, "NNTP-Posting-host:" ³oÓÄæ¦ì, ¦³¥¿¤Ï¸Ñµn¿ý
§¹¾ãªÌ, ³oÓÄæ¦ì, ´N¬O°O¿ý^¤å¦WºÙ; ¦pªG¤£¥þªÌ, ¨S¦³ªÌ, ´N¬O°O¿ý IP.
©ÎªÌ, §A¦p¤£²M·¡, ¤W±ªº»¡©ú. ¨SÃö«Y, ¥un§Aªº News reader, ³]©w¥¿±`,
¦³¶ñ¼g¥¿½Tªº e-mail address, ¨º»ò§A¦pªG¦b tw.bbs.test ³oÓ newsgroups
/board ±i¶K test article, ¨º»ò netnews.NCTU.edu.tw ³oÓ NetNews server,
¦¬¨ì¸Ó test article «á, «K·|±N¸Ó article ©â¥X, ¥Ñ news Âন e-mail,
±N¨ä±H¦^µ¹ì±i¶KªÌ. ( §ó¥¿½T¦a»¡, ¬O e-mail address Äæ, ©Ò°O¿ýªº
From: xxx user )
³oùئ³Ó¨Ò¤l ( click here )
¨ä¥¦¤èªk. ( ¦p nslookup, dig, ... )
¦pªG§A¦Û»{¦³·§©À, ¥i¥H¨Ï¥Î¤u¨ãµ{¦¡, ¹³ nslookup ¤§Ãþ¨Ó¬dÃÒ.
¤è¦¡ 1: ( ©³¤Uªº IP address, ´«¦¨§A·Q¬dªº IP address, XXX.YYY.WWW.ZZZ )
-------
% nslookup
Default Server: ns.NCTU.edu.tw
Address: 140.113.250.135
> 140.113.1.1
Server: ns.NCTU.edu.tw
Address: 140.113.250.135
Name: NCTU.edu.tw
Address: 140.113.1.1
>
¤è¦¡ 2:
-------
% nslookup
Default Server: ns.NCTU.edu.tw
Address: 140.113.250.135
> set type=ptr
> 1.250.113.140.in-addr.arpa
Server: ns.NCTU.edu.tw
Address: 140.113.250.135
1.250.113.140.in-addr.arpa name = WWW.nctu.edu.tw
250.113.140.IN-ADDR.ARPA nameserver = nctu.edu.tw
250.113.140.IN-ADDR.ARPA nameserver = ns.nctu.edu.tw
250.113.140.IN-ADDR.ARPA nameserver = ns2.nctu.edu.tw
nctu.edu.tw internet address = 140.113.1.1
ns.nctu.edu.tw internet address = 140.113.250.135
ns2.nctu.edu.tw internet address = 140.113.6.2
>
...