i admin one server on internet with only openssh,sftp via openssh , oracle 1521, tomcat, apache , the other ports has been closed by iptable,
however, today i can not connect to this website by sftp,
the client said, the protocol do not match any more, it is openssh -1.5-2.9v, anyway, it should been openssh-1.99-2.9v, as it has been worked for a long time.
my questiong is : whether i have been invade? or , why the openssh head could change?
thanks for your tips;