This is just a short post about using the Munin ip_ plugin to monitor traffic to and from particular hosts using iptables.
There are a number of posts that describe how to add
the necessary rules to iptables for counting traffic to each host that you're
interested in. Unfortunately, they all suggest using rules which are the wrong
way around. The correct rules should look like this (to monitor traffic to the
-A INPUT -s 192.168.0.1 -A OUTPUT -d 192.168.0.1
All the resources I found quoted the rules above with the
OUTPUT chains switched, meaning no traffic would ever be recorded.