Skip to main content

Unicast Reverse Path Forwarding (uRPF)

 


UNICAST REVERSE PATH FORWARDING (URPF) IS A SECURITY FEATURE THAT HELPS TO PREVENT IP SPOOFING ATTACKS. IT WORKS BY VERIFYING THAT THE SOURCE IP ADDRESS OF A PACKET IS REACHABLE FROM THE INTERFACE THAT THE PACKET WAS RECEIVED ON. IF THE SOURCE IP ADDRESS IS NOT REACHABLE, THE PACKET IS DROPPED.

URPF IS TYPICALLY USED ON ROUTERS THAT ARE CONNECTED TO THE PUBLIC INTERNET. THIS IS BECAUSE THE PUBLIC INTERNET IS A SHARED MEDIUM, AND IT IS EASY FOR ATTACKERS TO SPOOF IP ADDRESSES. URPF CAN HELP TO PROTECT NETWORKS FROM THESE ATTACKS BY PREVENTING THEM FROM FORWARDING SPOOFED PACKETS.

URPF HAS TWO MODES: STRICT MODE AND LOOSE MODE. IN STRICT MODE, THE PACKET IS DROPPED IF THE SOURCE IP ADDRESS IS NOT REACHABLE ON THE SAME INTERFACE THAT THE PACKET WAS RECEIVED ON. IN LOOSE MODE, THE PACKET IS DROPPED IF THE SOURCE IP ADDRESS IS NOT REACHABLE ON ANY INTERFACE.

URPF IS A VALUABLE SECURITY FEATURE THAT CAN HELP TO PROTECT NETWORKS FROM IP SPOOFING ATTACKS. HOWEVER, IT IS IMPORTANT TO NOTE THAT URPF CAN ALSO DROP LEGITIMATE TRAFFIC. THIS IS BECAUSE THERE ARE CASES WHERE A PACKET MAY BE RECEIVED ON AN INTERFACE, BUT THE SOURCE IP ADDRESS IS NOT REACHABLE ON THAT INTERFACE. FOR EXAMPLE, THIS CAN HAPPEN IF THERE IS AN ASYMMETRIC ROUTING PATH BETWEEN THE ROUTER AND THE SOURCE OF THE PACKET.

IF YOU ARE CONSIDERING DEPLOYING URPF, IT IS IMPORTANT TO CAREFULLY EVALUATE THE RISKS AND BENEFITS. YOU SHOULD ALSO MAKE SURE THAT YOU UNDERSTAND THE POTENTIAL IMPACT OF URPF ON LEGITIMATE TRAFFIC.

______________

Comments

Popular posts from this blog

DOS AND DDOS ATTACK

A Dos (Denial-Of-Service) Attack and A DDOS (Distributed Denial-Of-Service) Attack Are Both Attempts to Make a Computer System or Network Resource Unavailable to Legitimate Users. However, They Differ in How They Achieve This: Dos Attack: Imagine A Single Person Throwing Rocks at A Castle Gate. A This Person Represents the Attacker, And the Rocks Represent the Malicious Traffic. The Castle Gate Represents the Target System or Network Resource. The Attacker Keeps Throwing Rocks, Trying to Overwhelm the Gate's Defenses and Gain Entry. Dos Attacks Are Typically Launched from A Single System. They Can Be Effective Against Small Systems or Networks, But Larger Systems Can Often Withstand Them. DDos Attack: Imagine An Army Throwing Rocks at A Castle Gate. This Army Represents the Attacker, And the Rocks Represent the Malicious Traffic. The Castle Gate Represents the Target System or Network Resource. The Attackers Coordinate Their Attack, Throwing Rocks from Multiple Directions at Once. ...

Types Of Attack in Network

Common Network Attacks Explained. 1. Overwhelming a Network (DoS/DDoS): Imagine a restaurant that's flooded with too many customers. In a DoS/DDoS attack: A website is overwhelmed with too much traffic. 2. Eavesdropping on Conversations (MitM): Imagine someone listening in on your phone call. In a MitM attack: An attacker listens to your online conversations. 3. Tricking You (Phishing): Imagine receiving a fake email from your bank. In phishing: Attackers try to trick you into giving them your personal information. 4. Finding a Weakness in a Website (SQL Injection): Imagine finding a hole in a fence. In an SQL injection attack: An attacker finds a weakness in a website to steal or change data. 5. Planting a Hidden Camera (XSS): Imagine someone hiding a camera in a party. In an XSS attack: An attacker hides harmful code on a website to spy on you. 6. Guessing Your Password (Password Attck): Imagine trying to guess a friend's password. In a pas...

FLAOT ROUTE + NAT

  TOPOLOGY GO TO ISP-1 ROUTER AND ENTER THIS COMMANDS IN CONFIGURATION TERMINAL MODE . inter f0/0 ip address 202.56.215.1 255.255.255.0 no shutdown exit ip dhcp excluded-address 202.56.215.1 202.56.215.20  ip dhcp pool isp1 network 202.56.215.0 255.255.255.0 default-router 202.56.215.1 exit inter loopback 0  ip address 8.8.8.8 255.0.0.0 no shutdown exit write GO TO ISP- 2 ROUTER AND ENTER THIS COMMANDS IN CONFIGURATION TERMINAL MODE . inter f1/1 ip address 200.200.200.1 255.255.255.0 no shutdown exit ip dhcp excluded-address 200.200.200.1 200.200.200.100  ip dhcp pool isp2 network 200.200.200.0 255.255.255.0 default-router 200.200.200.1 exit inter loopback 0  ip address 8.8.8.8 255.0.0.0 no shutdown exit write GO TO R1 ROUTER AND ENTER THIS COMMANDS IN CONFIGURATION TERMINAL MODE . inter fa0/0 ip address 192.168.100.1 255.255.255.0 no shut exit inter f1/0 ip address dhcp no shutdown inter f1/1 ip address dhcp no shut ip dhcp pool manan network 192.168.100.0 255....