There are some non-obvious issues: 1. Why not firewall in the operating system and distribute/scale the load evenly ? Centralising the firewall was done when O

There are some non-obvious issues: 1. Why not firewall in the operating system and distribute/scale the load evenly ? Centralising the firewall was done when OS provisioning was bad, now we have Puppet/Chef/Ansible, firewalls operations is simple enough. 2. Simple firewalling is effectively worthless when 99% of all traffic is HTTP/S and SSH. To add value you perform flow analysis combined with deep packet inspection to build a meta-data data to pass through a heuristics/pattern analysis to perform threat detection. 3. Passing through any device creates latency in the order of milliseconds, which is not acceptable in east/west traffic loads. Parallelisation, caching, flow cut-through will all incur a latency penalty. HTH greg