>>479
$ host 219.125.148.182
182.148.125.219.in-addr.arpa domain name pointer wbcc1s13.ezweb.ne.jp.

$ whois -h whois.nic.ad.jp 219.125.148.182/e
Network Information:
a. [Network Number] 219.125.148.0
b. [Network Name] KDDI-NET
g. [Organization] DION (KDDI CORPORATION)

あとはDIONに聞いてね。