how to fight concurrent connection DOS attack to FreeBSD ftpd?

[Quan Qiu]

On Nov 24, 2007 10:34 PM, Zhang Weiwu <zhangweiwu at realss.com> wrote:
> I run a ftp site which is being attacked by someone who issue some 1000
> concurrent connection for downloading as anonymous. How can I fight back?

>
> If ftpd.conf is not the right manual page to read, can you suggest which
> configuration manual to read to fight back this attack? Thanks in advance!
>


Try wrapping your ftpd using inetd. There are some limits to max child
processes and max connections per ip in inetd.conf(5). An example for
vsftpd:

ftp     stream  tcp     nowait/50/10
        root    /usr/local/libexec/vsftpd       vsftpd

Refer to the inetd.conf(5) manpage for more.


-- 
裘佺 (QIU Quan) <jackqq at gmail.com>