Is there a free netflow collector that I can throw on a windows box?
ntop can act as a NetFlow collector and is available for Win32. You will have to recompile it by yourself though, or find pre-made builds (shouldn't be too hard, it's GPLv3 open source) since the provided build is limited to capturing 1000 packets per session.
Another option is offered by SolarWinds:
- has an add-on product to help you configure your Cisco router interfaces correctly
- only supports NetFlow v5
- limited to 60 minutes of data
Check out the Scrutinizer free version:
* Supports an unlimited amount of flow sending devices!!! * Network Mapping: Click Here for more details * Top Conversations * Top Hosts * Top Protocols * Application Groups: Viewing Application Groups and Define Application Groups * Quality of Service link to display the top ToS and DiffServ priority tags. * Displays the Autonomous Systems. * Drag and Drill Technology to drill in on time frames * Status Tab * Displays the volume of traffic for the selected host or port on the selected interface(s). * Displays the volume of unique conversations to (green) and from (blue) for the selected host or port on the selected interface(s). * Vitals Tab * SNMPv3 Support * Integration with 3rd party products * All flow data dropped at midnight (NOTE: One year trends of total in / out traffic are provided) * Denika free plugin to discover & display the SNMP statistics for a device. Includes Cisco's IP SLA and NBAR technologies. * Search for a specific host or application. * Google Maps * Free Initial Setup via Telephone Support * Support from the Email Forum
Scrutinizer drops all netflow data at midnight in its free version.
ManageEngine's Netflow Analyzer free version is limited to monitoring two interfaces, but it doesn't drop data. http://www.manageengine.com/products/netflow/index.html