We are running wu-ftpd-2.6.0-1 on our ftp-Server. If we get a lot of
simultanious requests, inetd stop listening to the ftp service(
no "LISTEN" entry for ftp in the output of netstat -a command). About 10
mintutes later inetd starts again listening to ftp service.
Add a max. rate to the ftp entry in /etc/inetd.conf:
ftp stream tcp nowait.NNN root /usr/sbin/tcpd in.ftpd -l -a
where NNN is something like 100.
See "man inetd.conf" for details.