Got error:

nf_conntrack: table full, dropping packet
?

Here is how to discover current limit and how much of it is used:

Code:
echo -e "LIMIT:\n"cat /proc/sys/net/netfilter/nf_conntrack_max;sysctl -a 2>/dev/null| grep conntrack_max;echo -e "CURRENT USAGE:";cat /proc/sys/net/netfilter/nf_conntrack_count
Here is how to increase the limit:

Code:
echo  "net.netfilter.nf_conntrack_max=99000" >  /etc/sysctl.d/10-conntrack-max.conf;sysctl -p  /etc/sysctl.d/10-conntrack-max.conf
There is also open files limit, i am unsure how related it can be, but one can also increase it:
Code:
echo "* hard nofile 10000" >> /etc/security/limits.conf