We have a small data center we're finishing. We have a core+spline and then redundant TOR switches. Everything is basically whitebox 10gb switches running Cumulus; although, we will upgrade the core within the next 12 months to be 40gb, but this gets us going for now.
Obviously there's a lot of traffic that winds up just being east-west type traffic specially in our OpenStack cluster. But we're having issues deciphering just how much traffic will wind up hitting the Firewall/ddos device that we're looking to buy.
We planned on using the Firewall to handle BGP, dDos and of course network entrance and exit firewall policy. But we simply do not know how much to calculate..
I've seen people use the Internet pipe to size the entire firewall, but this is really misleading since there's traffic not looking to entire or exit that might still hit a firewall policy; so I am hoping people who have gone before me have some sage advice on how to size firewalls.. For reference; here is our network setup...