The fw ctl debug command provides the flexibility to enable and manage debug flags for various kernel modules simultaneously (e.g., fw, vpn, cphwd). This capability is essential for troubleshooting complex issues that involve interactions between multiple Check Point software components, as their respective debug messages can be collected and correlated within the same buffer. In contrast, fw ctl zdebug is a specialized high-performance tool, primarily used to capture a single, high-volume stream of data, such as all dropped packets, where the overhead of the standard debug mechanism would be prohibitive. Therefore, the ability to debug multiple modules at once is a distinct benefit of fw ctl debug.

A. fw ctl zdebug uses a "zero-copy" mechanism for high-performance scenarios, making it fundamentally different from the standard fw ctl debug command.

B. Timestamps are critical for analyzing the sequence of events in kernel debugging and are present in the output of both commands.

D. Both fw ctl debug and fw ctl zdebug write to the same kernel debug buffer, whose size is configured independently and is not a feature of either command.

1. Check Point SecureKnowledge sk163415: "Kernel Debugging Essentials": This document explicitly contrasts the two commands. It describes fw ctl debug as "The classic way to perform a kernel debug. It allows you to set debug flags for different modules." It describes fw ctl zdebug as a tool for "debugging issues with high rate of logs, where the regular debug might be too slow." This highlights the multi-module flexibility of fw ctl debug versus the high-rate, single-purpose nature of zdebug.

2. Check Point R81.20 CLI Reference Guide:

On page 418, the guide details the fw ctl debug command with its -m parameter, stating its function is to "Set the kernel debug flags for the specified kernel module." This syntax underpins its use across multiple, distinct modules.

On page 422, the guide describes fw ctl zdebug, highlighting its common usage with the drop parameter (fw ctl zdebug drop) to capture all dropped packets, reinforcing its role as a specialized, high-volume capture tool rather than a flexible multi-module debugger.