That's a very practical and important question! When it comes to a "safe recommended value" for -t, it's less about a single universal number and more about context and ethical considerations.
For ethical security testing, particularly in a lab environment or against systems you own and have permission to test, the goal is often to find credentials without disrupting the service.
Here's a breakdown of what to consider:
- No Single "Safe" Number for All Situations: What's safe for one system might crash another. A modern, robust server might handle 64 or even 128 connections without issue, while an older, less powerful device might struggle with just 5 or 10.
- Default as a Starting Point: Hydra's default of
16(-t 16) is a reasonable starting point. It's often chosen as a balance between speed and not immediately overwhelming most common services. - Testing in a Controlled Environment:
- In a Lab (like LabEx): Feel free to experiment within reason. The VM itself can handle moderate load. If you're targeting a service within the VM, you can usually start with the default and even go higher (e.g.,
-t 32or-t 64) to see how it affects speed. Since it's a lab, the primary concern of accidentally harming a real-world system is removed. - Real-World Ethical Testing: If you were doing this against a real system (with explicit permission!), you'd start low (e.g.,
-t 4or-t 8), monitor the target system's performance, and gradually increase it while observing for any signs of performance degradation or detection.
- In a Lab (like LabEx): Feel free to experiment within reason. The VM itself can handle moderate load. If you're targeting a service within the VM, you can usually start with the default and even go higher (e.g.,
- Avoid DoS (Denial of Service): The primary reason to be cautious is to avoid inadvertently performing a denial-of-service attack on the target. This is especially critical when testing systems belonging to others where permission might not extend to causing service disruption.
In the context of the LabEx environment and learning Hydra:
I would recommend starting with the default -t 16 and understanding its impact. As you learn more, you can consider how increasing or decreasing this value might affect the speed and stealth of your operations for future exercises.
Always remember that in real-world scenarios, detailed reconnaissance of the target and its capabilities, along with explicit permission, would dictate the "safest" -t value.
Does that help clarify the considerations for choosing a t value?
