Changes
→Secure it
Add the following line into vz.conf to activate the respective iptables modules for all containers.
IPTABLES="ip_tables ipt_REJECT ipt_tos ipt_limit ipt_multiport iptable_filter iptable_mangle ipt_TCPMSS ipt_tcpmss ipt_ttl ipt_length ip_conntrack ip_conntrack_ftp ip_conntrack_irc ipt_LOG ipt_conntrack ipt_helper ipt_state iptable_nat ip_nat_ftp ip_nat_irc ipt_TOS"
[[http://wiki.debian.org/DebianFirewall][Configure]] your iptable rules inside the container.