I have two servers on two different IPs, lets say they are: 18.104.22.168 and 22.214.171.124. In addition, they both run some virtual machines, who all have private IPs 10.0.0.*. Now, these two servers only have a single ethernet interface each. I want to track total internet traffic to/from these machines from the outside world, but I do NOT want to count any traffic between the two machines or between the virtual machines. How would I set up an accounting rule, using either shorewall's accounting configuration, or plain iptables rules, to track this?
Currently, I have no way of knowing how much internet bandwidth I'm using, since when I look at the overall stats, it includes traffic between my two servers.
Ideally of course would be to ask the router, but that's not available right now.