April 7, 2010

Issues with FTP on CentOS 5.4

If you’re getting “data connection refused errors” when trying to ftp onto a CentOS box, make sure your ip_conntrack_ftp is loaded.
The default RH/CentOS iptables script includes a conntrack statement :

-A RH-Firewall-1-INPUT -m state –state ESTABLISHED,RELATED -j ACCEPT

but does not load the ftp module.
to fix on the fly run :

modprove ip_conntrack_ftp

to make sure it happens again on boot modify your /etc/sysconfig/iptables-config modules list :

IPTABLES_MODULES=”ip_conntrack_netbios_ns ip_conntrack_ftp”