Strongspaceなんか変

昨日からsftpでログインするとこんな感じ。

Connecting to xxxxx.strongspace.com...
Address 4.71.165.121 maps to 4-71-165-121.revdns.textdrive.com, 
but this does not map back to the address
- POSSIBLE BREAKIN ATTEMPT!

DNSの正引きと逆引きが不一致だな。

% host  4-71-165-121.revdns.textdrive.com
4-71-165-121.revdns.textdrive.com has address 207.7.108.21
% host 207.7.108.21
21.108.7.207.in-addr.arpa domain name pointer one.textdrive.com.