FTP server alternative IP address

Hi I have 2 IP addresses and I would like to point my ftp server to the 2nd address and not the mail IP address I have included in the conf file ftp.xxx.net.nz      0    IN      A    xxx.xxx.xxx.186 and  ftp      0      IN      CNAME      xxx.net.nz. but the ftp client only resolves to the main IP address of xxx.xxx.xxx.113 any suggestions please..

Thank You