If you have mastered the basics, try these advanced configurations:

Selfishnet v3.0.0 represents a compatibility update for a legacy network manipulation tool. While it demonstrates the power of ARP protocols and network packet capturing, it is a tool designed for exploitation rather than legitimate administration.

Warning: For legitimate bandwidth management (e.g., stopping a roommate from hogging all the data), the correct approach is Quality of Service (QoS) configuration on the router, not third-party client-side manipulation. QoS is a native feature in most modern routers that allows prioritization of traffic securely and legitimately without violating network protocols.

I understand you're asking about "SelfishNet v3.0.0 for Windows." However, I want to provide some important context before offering a write-up.

SelfishNet is a network management utility that was historically used for ARP spoofing — a technique that can intercept, monitor, or restrict other devices' internet access on a local network. While it has legitimate uses (e.g., network administrators testing security or parents managing kids’ screen time), it is more commonly associated with unethical or illegal activities like:

Because of these risks, many antivirus programs flag SelfishNet as a hacking tool or potentially unwanted program (PUP). Using it without explicit permission from the network owner may violate computer fraud laws (e.g., CFAA in the US, Computer Misuse Act in the UK).

To understand SelfishNet V3.0.0, one must understand ARP spoofing, also known as ARP poisoning. Every device on a local network maintains an ARP table that maps IP addresses to physical MAC addresses. When Device A wants to talk to the router (192.168.1.1), it asks: “Who has 192.168.1.1?” The router replies with its MAC address.

SelfishNet exploits this by sending forged ARP replies to both the target device and the router. It tells the target: “The router’s MAC address is actually my MAC address.” Simultaneously, it tells the router: “The target’s MAC address is also my MAC address.”

Result: All traffic between the target and the router passes through the SelfishNet user’s computer. From there, the software can:

In “Selfish Mode,” the software simply drops all incoming packets destined for other IPs while forwarding its own packets at maximum priority—an aggressive tactic that makes other users’ connections appear slow or dead.