Network Intelligence
Look up IPv4 and IPv6 addresses to find ISP, country, city, region, ASN, and organization details.
An IP lookup retrieves publicly available information about an IP address, including its geographic location, internet service provider (ISP), autonomous system number (ASN), organization, and network range. This data comes from regional internet registries and IP geolocation databases that map IP allocations to physical infrastructure. IP lookups are a foundational technique in network reconnaissance, threat investigation, and infrastructure documentation.
For security professionals, IP lookups provide immediate context when investigating suspicious traffic, phishing infrastructure, or compromised systems. When a log entry shows an unknown IP accessing a sensitive resource, an IP lookup can reveal whether it belongs to a known cloud provider, a foreign ISP, or a hosting company associated with malicious activity. This initial triage determines whether deeper investigation is warranted.
IP lookups also help defenders understand their own attack surface. By looking up the IPs that connect to their services, administrators can identify unexpected geographic regions, unauthorized hosting providers, or suspicious network ranges that warrant monitoring or blocking.
IP geolocation maps IP addresses to physical locations using databases maintained by regional internet registries (ARIN, RIPE NCC, APNIC, LACNIC, AFRINIC), commercial providers, and open-source projects. These databases record which organization holds each IP block, where that organization is registered, and sometimes where the IP is physically routed. Geolocation is an approximation, not a precise location, because IP blocks are allocated to organizations that may serve users across entire countries or continents.
The accuracy of geolocation varies by region and database. Country-level accuracy is typically high (95-99%), while city-level accuracy can vary from 50% to 80%. Cloud-hosted IPs may appear to be in the data center's location rather than the user's actual location. VPN and Tor exit nodes add another layer of indirection. For security purposes, use IP geolocation as one data point alongside other indicators rather than as definitive location evidence.
ASN data is often more useful for security investigations than geolocation. The ASN identifies the network operator (Google, Amazon, Microsoft, a specific ISP), which reveals whether an IP belongs to infrastructure you trust, a known hosting provider, or an unexpected network. ASN-based analysis helps map threat infrastructure across multiple IPs.
In incident response, IP lookups are often the first step when triaging alerts. A firewall log showing repeated connection attempts from an unfamiliar IP can be quickly investigated: look up the IP to determine the ISP, country, and ASN, then cross-reference with threat intelligence databases to see if it has been associated with known attacks. This triage separates genuine threats from benign traffic.
For phishing and malware investigations, IP lookups reveal the infrastructure behind an attack. Phishing pages are often hosted on compromised servers or bulletproof hosting providers. Looking up the IP of a phishing domain identifies the hosting network, which informs takedown requests and threat intelligence enrichment. Multiple phishing domains sharing the same IP or ASN indicate a coordinated campaign.
In web application security, IP lookups help identify bot traffic, credential stuffing sources, and scanning activity. When rate limiting or blocking IPs, understanding whether an IP belongs to a legitimate user's ISP, a cloud provider used by automated tools, or a known malicious network informs the response strategy.