What Is IP Spoofing & How Do You Prevent It?

Daily, we face various threats on the internet. These threats originate from different sources and affect us in many ways. One such threat is Spoofing. In lay terms, to spoof means to deceive or falsify. There are various forms of spoofing, but IP spoofing is the most notorious threat.

IP spoofing refers to an attempt by a cybercriminal to imitate or impersonate a user’s IP address and pretend to be that user to launch attacks on a local computer network. In IP spoofing, the hacker deceives a computer network into thinking that a connection is from a trusted source, such as another known computer network. The hacker then exploits this trust to wreak havoc on the receiving network.

Related: What is my IP address?

How IP Spoofing Is Executed

All data sent on a local computer network over the internet is broken down into smaller pieces called packets. These packets are transmitted singly and then reassembled at their destination. Each of these packets also has an IP (Internet Protocol) header, which carries necessary information about the packet, such as its originating and destination IP addresses.

The data is transferred over a TCP/IP protocol, and it is at this point, the hacker intercepts the connection. The first step for a hacker will be to determine a host IP address trusted by the target network. The IP spoof then changes the source or destination data on the IP addresses to resemble that of the trusted source in the IP headers. This manipulation deceives the sender or receiver into believing that the connection was successfully established with the other party.

Types of IP Spoofing Attacks

IP spoofing is often used to launch various attacks on a computer network. Some of such attacks include:

1. Firewall Bypass and IP authorization

A cybercriminal can use IP spoofing to bypass cybersecurity systems such as firewalls. This bypass is especially so for systems that use blacklists and whitelists. Whitelists are authorized IP addresses, while blacklists contain unauthorized addresses whose access is blocked. Hackers can use IP spoofing to circumvent these authentication protocols since a device’s IP address is a significant identifier. A blacklisted hacker only has to falsify a whitelisted IP address to be granted access.

2. Man-in-the-Middle(MITM) Attacks

To execute a MITM attack, the hacker takes a position between two devices to intercept and alter the exchanged packet data. The hacker can also intercept communication between an internet user and a website. In this case, the user thinks they are communicating with the website, while the website thinks it’s communicating with the legitimate user. This attack usually occurs over unsecured wifi connections. A MITM hacker will be able to snoop on all the communications between the website and the internet user. So, no data shared is secure.

3. DoS and DDoS Attacks

Denial of Service (DoS) and Distributed Denial of Service (DDoS) attacks occur when target websites or servers are overwhelmed with traffic making them unavailable to users. A DoS attack usually originates from a single computer system, while a DDoS attack involves multiple systems attacking one system. IP spoofing can be exploited by DoS/DDoS attackers to hide the source of these attacks so that they cannot be traced and shut down. This anonymity created by a spoof attack makes the DoS attack more lethal.

How to Detect IP Spoofing

It is especially necessary to detect IP spoofing attacks as soon as they occur to protect your computer network from any further attacks. Although, this is incredibly difficult, through these two means, you can detect IP spoofing on your network:

How to Prevent IP Spoofing

It isn’t easy to ensure that their legitimate owners are operating all the IP addresses on your network. However, there are measures you can take to prevent IP spoofing and other attacks.

  1. Access Control Lists: An access control list can help you limit and control the IP addresses that can access your local network. This way, you can deny access to private IP addresses trying to interact with your network.
  2. Packet Filtering: Packet filtering is one of the most effective means of controlling network traffic. With this feature, you can filter inbound and outbound traffic, making it easy to block any traffic from suspicious sources. Ingress filtering prevents your network from receiving packets determined to originate from a different IP address from that contained in the IP header. Egress filtering prevents packets from leaving your network if the IP header appears to have been tampered with.
  3. Authentication: Authenticating all the interactions among the devices on your network will help you spot any spoofed interactions. You can consider using IPsec protocols, as they are suitable for authentication and encryption.
  4. Reconfigure and Encrypt Your Routers and Switches: You will need to change your routers’ configuration and controls to reject packets originating from sources external to the computer network but claiming to originate from within the network. It would also be wise if your routers are encrypted so that trusted external hosts can communicate securely with your local hosts.
  5. Visit Only Secure Websites: You should also try as much as possible to limit your browsing to only secure HTTPS websites. This carefulness is because these websites use SSL/TLS protocol, which encrypts your connection with them, making it safe.
  6. Migrate to IPv6: Websites should also consider migrating to IPv6 internet protocol to provide their users with better online security. IPv6 is specifically built to tackle security issues such as IP spoofing. The protocol guarantees encryption on websites, with authentication measures.
  7. Use Antivirus Software: Even after taking the steps above, it is necessary to know if you have been the target of IP spoofing. This is why you need a spoofing detection software, such as an antivirus. You should also note that the usual antivirus programs only have a scanning program for suspicious or malicious software activities. They don’t have any specific procedures for spoofing protection, so, check for a “next-generation” or “endpoint protection” antivirus. These antivirus types have malware protection beyond blacklisting suspicious software activities and are advanced enough to spot unusual activity.
  8. Use a Virtual Private Network (VPN): VPNs are also a great way to guarantee your network’s online security. Most good VPNs use military-grade encryption to protect your internet traffic. This encryption level makes it difficult for hackers to listen in on your traffic or spoof either yours or your destination’s IP addresses. It is also significant that many VPNs allow simultaneous connections on a single subscription, and some even allow unlimited subscriptions. The simultaneous connections feature means that you can protect many or all of the devices on your local network with a single VPN subscription.

Is IP Spoofing Illegal?

So far, we have seen that spoofing on the internet does more harm than good for a lot of users. With all the damage that IP spoofing can cause, the legality of IP spoofing can start to play around in your mind. Is IP Spoofing legal or not?

While you may be quick to go with the choice “illegal”, IP spoofing in itself is not unlawful. When you use a VPN or proxy, you’re spoofing your IP address to browse securely and safely. However, where you spoof your IP address to commit cybercrimes such as identity theft, it is illegal.

Furthermore, IP spoofing is used during performance tests for websites. During these tests, many Vusers (virtual users) are created to test what will happen upon the website’s launching, when many users log on. Since each user participating in the test already has an IP address, IP spoofing can be used to assign them a different “return address.”

It is necessary to note that internet laws vary in many parts of the world and a few of them may be averse to IP Spoofing or any other type of related activity. Countries like China and Russia have unfriendly internet laws and frown on internet activities that may be considered legal in many other countries.


Your IP address is a vital part of your online identity, and you should protect it. If it is spoofed, the attacker can harm your internet security in many ways. The spoof can eavesdrop on your internet traffic, steal your sensitive data, or even commit cybercrimes in your name. Therefore, take the threat of IP spoofing seriously and engage active measures to protect your devices and computer network from any IP spoofing attacks.

Related Posts