Galexrt iptables: Using statistic module
This post will show some examples using the iptables statistic module random mode.
"Load Balance" with iptables between two servers
Kubernetes uses this method to load balance traffic between pods in the cluster.
The commands below create separate chains for each server and for the load balancing of port 80 in this case:
iptables -t nat -N LB_PORT80
iptables -t nat -N LB_PORT80_SERVER1
iptables -t nat -A LB_PORT80 \
-m statistic --mode random --probability 0.5000 \
-j LB_PORT80_SERVER1
iptables -t nat -N LB_PORT80_SERVER2
iptables -t nat -A LB_PORT80 \
-j LB_PORT80_SERVER2
iptables -t nat -A INPUT -p tcp -m tcp --dport 80 -j LB_PORT80
Dropping packages with a X% probability from a specific IP address
My favorite rule to mess with people ;)
iptables -A INPUT \
-s IP_ADDRESS \
-m statistic --mode random --probability 0.5000 \
-j DROP
These are only two examples, but there many more possibilities to utilize the iptables statistic module.