What Is eBPF?

eBPF, short for extended Berkeley Packet Filter, is a Linux kernel technology that lets approved programs observe or influence system behavior without requiring a traditional custom kernel module. In practice, eBPF is widely used for Linux security, observability, networking, performance monitoring, and Kubernetes runtime visibility because it can inspect activity close to the operating system itself.

If you are exploring related cloud-native topics, it also helps to read what is kubernetes security posture management and what is runtime security.

eBPF definition

At a high level, eBPF allows small programs to run in a controlled way inside the Linux kernel. Those programs can attach to specific events, such as:

• Process execution
• File access
• Network connections
• System calls
• Security-relevant kernel hooks

When the event happens, the eBPF program runs and can collect telemetry, update counters, or sometimes help enforce a decision.

How eBPF works

Linux systems generate a constant stream of events. A process starts, a container opens a socket, a file is read, or a DNS request goes out. eBPF gives tools a way to hook into those events and inspect what is happening in near real time.

A simplified eBPF flow looks like this.

1. An eBPF program is loaded

A security, networking, or observability tool loads an eBPF program into the kernel. This usually happens through a user-space component such as an agent or daemon.

2. The kernel verifies it

Before the program is allowed to run, the kernel verifier checks it for safety constraints. This is one reason eBPF became so important: it provides a more controlled model than arbitrary kernel extension code.

3. The program attaches to a hook point

The eBPF program is attached to a specific event source, which might include:

• A tracepoint
• A syscall-related hook
• A network path
• A security event
• A performance monitoring point

4. The event occurs

When that event happens, the eBPF program runs automatically.

5. Telemetry or action is produced

The program can then:

• Collect metadata
• Send events to user space
• Track counters or maps
• Correlate process and network activity
• Support security or networking decisions in some use cases

Why the verifier matters

The verifier is a key part of the eBPF model. It examines the program before execution to reduce the chance of unsafe behavior crashing the kernel or creating unstable runtime conditions.

That does not make eBPF risk-free. It does mean eBPF was designed to be safer and more constrained than simply loading custom kernel logic with fewer checks.

What eBPF is used for

eBPF started with packet filtering concepts, but modern usage is much broader.

Observability

eBPF is widely used for deep observability because it can capture runtime details that are otherwise hard to collect cleanly.

Common observability use cases include:

• Tracking syscall behavior
• Measuring latency and performance bottlenecks
• Mapping network flows to processes
• Tracing service interactions
• Understanding container behavior on shared hosts

Runtime security

Security teams use eBPF to monitor system behavior close to the kernel. That makes it useful for detecting suspicious runtime activity such as:

• Unexpected process launches
• Privilege changes
• Sensitive file access
• Suspicious network connections
• Container escapes or policy violations
• Unusual syscall patterns

This is especially valuable in Linux and container environments where workloads may appear and disappear too quickly for older monitoring approaches.

Networking

Some platforms use eBPF for networking functions such as:

• Traffic inspection
• Packet filtering
• Network policy enforcement
• Load balancing
• Flow visibility

In these scenarios, eBPF is not just collecting telemetry. It can be part of the actual data path.

Performance monitoring and troubleshooting

Infrastructure and SRE teams use eBPF for low-level diagnostics, including:

• CPU and memory behavior
• Kernel and application latency
• Network bottlenecks
• Storage and I/O issues
• Process-level resource analysis

Why security teams care about eBPF

From a security perspective, eBPF matters because it can answer questions that are otherwise difficult to answer quickly.

For example:

• Which process opened this outbound connection?
• Which container made this DNS request?
• What parent process launched this shell?
• Did this workload read a sensitive file?
• Is this host showing suspicious syscall behavior?

That kind of runtime context is useful for detection, threat hunting, and incident response.

When you will encounter eBPF

You are most likely to encounter eBPF in Linux-heavy, security-focused, or cloud-native environments.

Kubernetes and cloud-native platforms

Many modern Kubernetes security and observability tools use eBPF to monitor containers and workloads with better runtime detail. This is especially helpful in dynamic environments where traditional host logging can miss important context.

Linux security tooling

If you evaluate host telemetry, runtime detection, or container security platforms, eBPF often comes up because many vendors use it to improve visibility into process, file, and network behavior.

SRE and performance engineering

Even outside security, eBPF is common in Linux troubleshooting and performance analysis. Security teams may encounter it first through shared observability tools before adopting it directly.

Incident response and threat hunting

Responders may use eBPF-based telemetry to watch suspicious behavior live, such as a process spawning children, opening sensitive files, or reaching unusual network destinations.

Benefits of eBPF

Key benefits include:

• Deep visibility close to the kernel
• Strong context for process, file, and network events
• Good fit for dynamic container environments
• Flexible support for observability and security use cases
• Reduced dependence on older collection models

Limits and practical considerations

eBPF is powerful, but it is not magic.

Teams still need to consider:

• Linux kernel compatibility
• Performance overhead in specific implementations
• Quality of the user-space tooling
• Access controls around who can load or manage eBPF programs
• Operational complexity in large fleets

Like many powerful technologies, its value depends on how well it is implemented and operationalized.

Bottom line

eBPF is a Linux kernel capability that enables deep visibility and selective control over system activity. For security and infrastructure teams, its value is straightforward: it helps show what hosts, containers, and workloads are actually doing in real time, especially in modern Linux and Kubernetes environments where traditional monitoring often falls short.