IP address blocking

IP address blocking

IP address blocking is a configuration of a network service that blocks requests from hosts with certain IP addresses. IP address blocking is commonly used to protect against brute force attacks and to prevent access through a disruptive address.

It can be used to restrict access to or from a particular geographic area, for example, content syndication to a specific region, also known as geolocation and geoblocking.

functioning of IP address

Each device connected to the Internet is assigned a unique IP address, which is necessary to allow devices to communicate with each other. With appropriate software on the host website, the IP address of site visitors can be recorded and can also be used to determine the geographical location of the visitor.

The collection of IP address data can, for example, look at whether a person has visited the site before, for example, to vote more than once, as well as to monitor their viewing pattern, how long they have been performing activity on the site (and estimate a waiting time), and so on.

Knowing the geolocation of the visitor indicates, in addition to other things, the country of the visitor. In some cases, requests or responses to a certain country would be blocked entirely. Geo-blocking has been used, for example, to target Nigerian IP addresses due to the perception that all companies originating in the country are fraudulent, making it extremely difficult for legitimate companies based in the country to interact with their counterparts in the rest of the country and around the world. To shop abroad, Nigerians must rely on proxy servers to hide the true origin of an Internet request.

Internet users can bypass geo-blocking and censorship to protect their personal identity and location in order to remain anonymous on the internet using a VPN connection.

On a website, an IP address block can prevent access to a disruptive address, although a warning and/or account block may be used first. Dynamic allocation of IP addresses by ISPs can complicate the blocking of incoming IP addresses, making it difficult to block a specific user without blocking many IP addresses (blocks of IP address ranges), creating collateral damage.


Unix-like operating systems typically implement IP address blocking using a TCP wrapper, configured by the host access control files /etc/hosts.deny and /etc/hosts.allow.

Companies and schools offering remote user access use Linux programs such as DenyHosts or Fail2ban to protect against unauthorized access while allowing authorized remote access. This is also useful for allowing remote access to computers. It is also used for internet censorship.

Avoid address blocking

Proxy servers and other methods can be used to bypass IP traffic blocking. However, anti-proxy policies are available.

In a 2013 U.S. court decision in Craigslist v. 3Taps, U.S. Federal Judge Charles R. Breyer found that bypassing an address block to access a website violated the Computer Fraud and Abuse Act (CFAA) for “unauthorized access,” punishable by damages.

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