The talk is about DDoS detection using an open-source tool called FastNetmon. The speaker, Pavel, explains that FastNetmon is a cross-platform application implemented in modern C++ that helps detect and mitigate DDoS attacks for networks. The tool provides real-time data from routers and offers various dashboards to monitor network traffic. FastNetmon can identify DDoS attacks within seconds and provides options for blocking the attacked host using BGP Blackhole. The speaker also mentions that FastNetmon is an open-source project driven by community contributions and offers various ways to automate actions and integrate with other protocols. The talk concludes with a Q&A session where participants ask questions about extending data collection with other protocols and using BGP FlowSpec for blackholing attacks.