Analyze network infrastructure, routing paths, and IP ownership with our free ASN Lookup tool. Enter any Autonomous System Number (ASN), domain name, or IP address to retrieve comprehensive network intelligence, BGP route details, and organization ownership data.

What is an Autonomous System Number (ASN)?

An Autonomous System Number (ASN) is a unique identifier assigned to a collection of IP networks managed by one or more network operators under a single routing policy.

Managed by global internet registries like IANA, RIPE, ARIN, APNIC, LACNIC, and AFRINIC, ASNs enable Border Gateway Protocol (BGP) routing across the internet, allowing data packets to find the shortest and most secure path between different networks.

What Data Does This ASN Lookup Tool Provide?

Our tool queries global WHOIS databases and BGP routing tables to deliver complete network insights:

• ASN Ownership Details: Identifies the company, ISP, hosting provider, or organization that owns the network.
• IP Address Ranges (IPv4 & IPv6): Displays all IP prefixes and subnets announced by the specific ASN.
• BGP Routing & Peering Data: Shows upstream providers and network interconnection paths.
• Geographic Location: Identifies the primary country and region where the network operates.
• Registration Metadata: Includes allocation dates, registry sources (ARIN, RIPE, etc.), and WHOIS contacts.

Why Perform an ASN Lookup?

1. Cybersecurity & Threat Intelligence

Security analysts and SOC teams use ASN lookups to investigate malicious IP addresses, track botnets, and block entire compromised network blocks before they affect local infrastructure.

2. Network Administration & BGP Debugging

Network engineers rely on ASN data to verify BGP announcements, troubleshoot routing anomalies, and audit peering arrangements between Internet Service Providers.

3. Competitor & Hosting Infrastructure Analysis

Discover where websites or online services are hosted. An ASN lookup reveals whether a site uses infrastructure from AWS, Cloudflare, DigitalOcean, or private data centers.

How to Use the ASN Lookup Tool

1. Enter Input: Type an ASN (e.g., AS13335 or 13335), an IP address (e.g., 1.1.1.1), or a domain name.
2. Execute Search: Click the Lookup button to process the query.
3. Analyze Results: Review the full breakdown of owner information, announced subnets, and routing data.

Frequently Asked Questions (FAQs)

What is the difference between an 2-byte and 4-byte ASN?

Originally, ASNs were 16-bit numbers (ranging from 1 to 65535). Due to rapid internet growth, IANA introduced 32-bit (4-byte) ASNs, expanding the pool to over 4 billion unique numbers.

What is the difference between Public and Private ASNs?

Public ASNs (1 to 64511 and 65552 to 419999) are used for internet routing via BGP. Private ASNs (64512 to 65534 and 4200000000 to 4294967294) are reserved for internal enterprise networks and are not routed on the public internet.