Suricata — IDS/IPS That Keeps Up With Modern Traffic
What it is
Suricata is an open-source security engine that rolls together intrusion detection, intrusion prevention, and network monitoring. It’s maintained by the Open Information Security Foundation and has become a go-to choice for admins who need visibility without locking into a vendor. The main difference from older IDS tools is that it’s multi-threaded. In practice, that means it can keep up with high-speed links instead of dropping packets when traffic spikes.
How it works in practice
Suricata can sit on an interface and watch traffic live, or it can chew through packet captures if you’re doing forensic work. It understands protocols like HTTP, TLS, DNS, and SMB, so it’s not just looking for byte patterns — it actually parses what’s going on. Detection rules are mostly Snort-compatible, with extra Suricata extensions. Logs come out in JSON (EVE format), which slide nicely into ELK, Splunk, or Grafana. If you want raw packets for later, it can dump full PCAPs too.
On the performance side, it supports AF_PACKET, PF_RING, or DPDK, depending on your setup. With a bit of tuning on the NIC and CPU pinning, it’s comfortable in multi-gigabit environments.
Everyday uses
– IDS at the edge to catch scans, exploits, or brute-force traffic.
– IPS inline when you actually want bad traffic dropped, not just logged.
– Feeding SIEMs with structured logs for hunting and correlation.
– Research labs where you need protocol breakdowns and replayable packet traces.
– Quick packet captures for troubleshooting when “something odd” is happening.
Installation quick notes
On Ubuntu/Debian:
sudo apt update && sudo apt install suricata -y
sudo systemctl enable –now suricata
Run in IDS mode on eth0:
sudo suricata -i eth0 -c /etc/suricata/suricata.yaml
On RHEL/CentOS:
sudo yum install epel-release -y
sudo yum install suricata -y
For inline IPS, pair it with NFQUEUE or nftables and set drop rules in the config.
Strengths and caveats
The big plus is speed and flexibility: multi-threading, rich protocol awareness, JSON output that’s easy to parse. But rules need care — noisy sets can drown you in alerts. Inline mode works, but misconfigured rules can break apps. Logs get heavy fast, so storage and rotation must be planned. And while Windows builds exist, serious deployments stick to Linux.
How it compares
| Tool | Edge | Where it fits |
| Suricata | Multi-threaded, JSON logs, IPS mode | Enterprises, SOCs, ISPs |
| Snort | Huge rule ecosystem, long history | Shops already tied into Snort workflows |
| Zeek | Protocol detail, scripting | Threat hunting, deep context |
| NGFW/WAF | App-level controls | Narrow use cases like web/API protection |
