The ProFTPD on SuSe needed the following additional directive
in the proftpd.conf cofiguration file:
to start correctly with an virtual IP configuration.
We added this to the Tutorial on Howtoforge too.
Explanation from the proFTPD vHosting Howto:
There is one last configuration directive about which an administrator should know: SocketBindTight. By default, the proftpd daemon will listen on all addresses, port 21, for the connection requests of remote clients. Sometimes, the administrator may wish to have the proftpd daemon listen only on the IP addresses for which it has been configured, and not every address. To accomplish this, simply use the SocketBindTight configuration directive:
This configures the daemon to "bind tightly" only to those IP addresses to which it has been configured to listen, rather than every address. By default, the proftpd daemon will listen to every address on the host machine.
Intersting thing: On e.g Debian or Mandrake this directive is not nescessary,
maybe its related to the newer ProFTPD version.