Netflow Traffic Analysis Hot! -
| Field | Description | Example | |-------|-------------|---------| | Source IP | Where traffic originates | 192.168.1.100 | | Destination IP | Target of communication | 8.8.8.8 | | Source Port | Application on source | 54322 (ephemeral) | | Destination Port | Service on destination | 443 (HTTPS) | | Protocol | Layer 4 protocol | TCP (6), UDP (17) | | Packets & Bytes | Volume of transfer | 1,200 packets / 1.4 MB | | Timestamps (Start/End) | Flow duration | 14:32:10.100 – 14:32:10.950 |
Date: [Current Date] Prepared By: Network Operations & Security Team Version: 1.0 (Operational Guide) 1. Executive Summary NetFlow (originally developed by Cisco) and its variants (IPFIX, sFlow, NetStream) provide the ability to collect and analyze IP traffic metadata. Unlike full packet capture (which is resource-intensive), NetFlow summarizes who , what , where , when , and how of network conversations. netflow traffic analysis
Implementing NetFlow analysis transforms a reactive, "black box" network into a measurable, observable system. It is essential for capacity planning, security incident detection, and troubleshooting performance issues. Implementing NetFlow analysis transforms a reactive
| Panel | Purpose | Alert Threshold | |-------|---------|----------------| | Top Talkers (IPs) | Identify bandwidth hogs | >200 Mbps for >10 min | | Top Applications (by port & protocol) | Unusual app usage | Non-standard ports >10% of total | | Conversation Matrix | East-West traffic visibility | Unusual server-to-server chatter | | Protocol Distribution | TCP/UDP/ICMP ratio | >5% ICMP (possible scanning) | | Asymmetric Routing Flag | Flows with mismatched interfaces | >1% of total flows | | DDoS Signature (Flood) | Single IP with >10k flows/min | Threshold per interface | | Feature | Full NetFlow (All flows) | Sampled NetFlow (1 in N packets) | |---------|--------------------------|----------------------------------| | Accuracy | 100% | ~1/N probability of missing flows | | CPU load on router | High (10-20%) | Low (1-3%) | | Storage required | Very high | Low | | Security use (C2 detection) | ✅ Yes | ❌ Risky (can miss beacons) | | Bandwidth top-N reporting | ✅ Yes | ✅ Acceptable | "black box" network into a measurable
