Nslookup
I would like to highlight this interesting Microsoft article and debug switch to have more debug capability when nslookup is launched and there are some unknown DNS query problems.
Scripting - Il comando NSLOOKUP parte 2 (piu' DIG)
Scripting - comando nslookup
Server - How to verify that your mail server work properly
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Nslookup's debug mode is a useful troubleshooting feature; you can set the local computer into this mode by typing set debug , or for even greater detail, set d2 . In debug mode, Nslookup lists the steps being taken to complete its commands, as shown in this example:
C:\>nslookup(null) testpc1.reskit.comAddress: 172.16.8.190> set d2> rain-city(null) testpc1.reskit.comAddress: 172.16.8.190------------SendRequest(), len 49HEADER:opcode = QUERY, id = 2, rcode = NOERRORheader flags: query, want recursionquestions = 1, answers = 0, authority records = 0, additional = 0QUESTIONS:rain-city.reskit.com, type = A, class = IN------------------------Got answer (108 bytes):HEADER:opcode = QUERY, id = 2, rcode = NOERRORheader flags: response, auth. answer, want recursion, recursion avail.questions = 1, answers = 2, authority records = 0, additional = 0QUESTIONS:rain-city.reskit.com, type = A, class = INANSWERS:-> rain-city.reskit.comtype = CNAME, class = IN, dlen = 31canonical name = seattle.reskit.comttl = 86400 (1 day)-> seattle.reskit.comtype = A, class = IN, dlen = 4internet address = 172.16.2.3ttl = 86400 (1 day)------------(null) seattle.reskit.comAddress: 172.16.2.3Aliases: rain-city.reskit.com