GeoIP blocking is a network security technique that restricts or allows traffic based on the geographic location of the source IP address. By mapping IP addresses to countries or regions using geolocation databases, organizations can implement location-based access policies that reduce their attack surface by blocking traffic from regions where they have no legitimate business operations.
GeoIP blocking relies on databases that map IP address ranges to geographic locations. These databases are maintained by providers like MaxMind and IP2Location, who compile allocation data from Regional Internet Registries. Implementation occurs at firewalls, web application firewalls, CDN edge nodes, or DNS resolvers. When a connection request arrives, the system resolves the source IP to a country code and evaluates it against the configured policy. Policies can whitelist specific countries (allowing only traffic from approved locations), blacklist specific countries (blocking traffic from high-risk regions), or apply different security controls based on origin. Organizations typically start by analyzing their legitimate traffic patterns to identify which countries generate valid traffic, then block regions that produce only attack traffic. GeoIP policies must account for VPNs, CDN proxies, and satellite internet services that can make traffic appear to originate from unexpected locations.
A significant portion of attack traffic originates from specific geographic regions where threat actors concentrate. Organizations that only serve customers in specific countries can dramatically reduce their attack exposure by blocking traffic from irrelevant regions. GeoIP blocking reduces noise in security logs, decreases the volume of automated attacks, and focuses defensive resources on traffic from regions that matter. While not a standalone defense, it meaningfully shrinks the attack surface.
CDA incorporates GeoIP blocking within the Threat Intelligence and Defense domain. Our missions help organizations analyze traffic patterns, design GeoIP policies that avoid blocking legitimate users, implement location-based controls across their infrastructure, and maintain accurate geolocation databases for reliable enforcement.