Blog
Guides and field notes on network traffic, flow data, and finding problems before your users do.
See NetFlow traffic by ASN and country
Turn flow records into networks and countries, even from a firewall that reports AS 0, and know which "country" your report is really showing.
Why your NetFlow collector shows no flows
No flows, or "no template received"? Check four places in order, from the exporter to the collector, and learn why v9 and IPFIX data waits for its template.
Export NetFlow from pfSense with softflowd
Set up softflowd on pfSense, send flows to a collector, and check the totals: on our firewall the reverse counters carried most of the WAN traffic.