digもいいけど nslookupコマンドの set debug オプションが結構いい感じ。 > . Server: 127.0.0.1 Address: 127.0.0.1#53 - QUESTIONS: ., type = A, class = IN ANSWERS: AUTHORITY RECORDS: -> . origin = A.ROOT-SERVERS.NET mail addr = NSTLD.VERISIGN-…