Scenario: Monitor Internet traffic via Netflow in a hub-spoke VPN network with Cisco ASA firewalls over cable/DSL connections (6Mbit down / 1Mbit up). VPN traffic carries Corp data but Internet surfing goes out each firewall. PRTG server is in the core network.
Question: What is the most efficient way to monitor Internet traffic via Netflow on a Cisco ASA? Install a remote probe in each site and create a Netflow sensor...or... install Netflow sensors for each site on the PRTG server in the core network?