eBPF (Extended Berkeley Packet Filter) is a revolutionary technology in the Linux kernel that enables developers to run sandboxed programs directly in the kernel space. Among its many use cases—security, performance tuning, and observability—**monitoring and analyzing network traffic** stands out as one of the most powerful.
In this blog, we’ll dive into what eBPF traffic means, how it works, and why it’s becoming the backbone of next-generation network observability.
What is eBPF Traffic?
eBPF traffic is the network data that's captured and processed with eBPF programs executed within the Linux kernel. Rather than using packet capture tools such as tcpdump or intrusive inline proxies, eBPF enables you to attach light programs to different network hooks within the kernel.
These hooks can monitor and manipulate:
- Incoming and outgoing packets
- System calls pertaining to network I/O
- TCP and UDP connections
- DNS requests and replies
- HTTP headers and bodies
Since eBPF programs execute in-kernel, they are able to monitor traffic with very low overhead and high performance, which makes them well-suited for real-time monitoring.
How eBPF Captures Network Traffic
eBPF programs can be linked to Linux kernel tracepoints, kprobes, uprobes, and cgroups. For network traffic, eBPF is typically linked to:
- Socket-level events: in order to trace send/receive syscalls
- Network interface points: such as XDP (eXpress Data Path) for filtering packets
- Protocol layers: to log and parse certain protocol headers
These programs are often coded in a limited version of the C language and checked by the kernel for safety and performance. Loaded, they may:
- Detect strange traffic
- Log communication between services
- Implement network policies
- Gather metrics (latency, error rates, throughput)
And the best thing? All this is done without changing application code or introducing agents.
Advantages of Utilizing eBPF for Traffic Monitoring
- High Performance
eBPF eliminates context switching between kernel and user space, reducing overhead by a large margin relative to standard packet analysis tools.
- Deep Visibility
eBPF provides access to detailed information—from layer 3 (network) through layer 7 (application)—for full-stack traffic observability.
- No Sidecars or Proxies
Unlike service mesh proxies (such as Envoy), eBPF is able to observe traffic without sidecars, which saves resources and complexity.
- Real-time Metrics and Security
eBPF traffic monitoring can immediately sense anomalies, spikes in latency, or suspicious flows, which is critical to performance tuning and security.
eBPF Traffic in the Wild: Use Cases
- Microservices Observability: Observe HTTP and gRPC calls between services without adding instrumentation.
- Zero-Trust Security: Log or block unwanted traffic between workloads.
- DNS Monitoring: Identify misconfigured or malicious DNS requests.
- Application Performance Monitoring: Trace request/response times and detect bottlenecks in production.
One of the most thrilling uses of eBPF traffic observability is how it's incorporated into tools such as Cilium, Pixie, and Keploy. These tools leverage eBPF in the background to ingest live traffic, produce telemetry, and even auto-generate tests.
How Keploy Utilizes eBPF Traffic for Testing
[Keploy](https://keploy.io/) is an automated testing platform that takes live API traffic through eBPF and auto-generates unit and integration tests without any need for scripting.
Here's how it works:
- Capture: Keploy employs eBPF to monitor incoming and outgoing API calls, payloads, and external dependencies.
- Generate: It generates test cases and mocks from actual traffic patterns.
- Replay: These tests can then be replayed in CI/CD environments for quick and trustworthy validation.
This traffic-driven approach, fueled by eBPF, guarantees that your tests are not just precise but also derived from real usage, minimizing blind spots and enhancing coverage.
Future of eBPF Traffic Monitoring
eBPF adoption is increasing exponentially. As Kubernetes, cloud-native applications, and edge computing grow larger, old monitoring and debugging methods are hitting their limits. eBPF provides a programmable, high-performance, and accurate solution.
We can expect even greater eBPF adoption in:
- Cloud security solutions
- DevOps toolchains
- Observability frameworks
- Test frameworks like Keploy
Final Thoughts
eBPF traffic analysis is changing how we monitor and interact with our systems. It offers unprecedented visibility into what is occurring at the kernel level, providing developers, DevOps, and security teams with the insight they require—without hitting performance or being intrusive.
You're optimizing network performance, hunting down a bug, or auto-generating tests from actual traffic—eBPF is becoming an indispensable tool to have in your DevOps toolkit.
Want to see it in action? Begin experimenting with traffic-based testing at [Keploy.io]