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(also blacklist)

Blocklist definition

A blocklist is a security tool that identifies unwanted or harmful entities, such as IP addresses, websites, applications, or email addresses, and prevents them from accessing a particular system or network. It's like a “Do Not Enter” sign for your digital space, barring identified threats from interacting with your system or data. Unlike an allowlist, which permits access to specified entities, a blocklist operates on the principle of ”allow by default, block by exception.”

See also: application allow-listing, firewall

Blocklist examples

  • IP blocklist: A list of IP addresses deemed to be untrustworthy or associated with malicious activities, prohibited from accessing a network or server.
  • Email blocklist: A list of email addresses identified as sources of spam or malicious content which are prevented from reaching a user's inbox.
  • Website blocklist: A list of websites known to host malware, phishing scams, or inappropriate content, which a user or network is prevented from accessing.

Managing blocklists

  • Keep your blocklists updated to protect against new threats.
  • Use reliable security software to automatically update and enforce your blocklists.
  • Balance blocklists with allowlists for comprehensive network security.