ASN Lookup (Autonomous System Number & BGP Data)
Find the ASN for any IP address, domain, or network. This tool provides detailed BGP routing data, IP prefixes, network ownership, and ISP information in real time.
What is an ASN?
An Autonomous System Number (ASN) is a unique identifier assigned to a network operator. It is used in BGP (Border Gateway Protocol) routing to identify networks on the internet.
- • Organization name and type
- • Country of registration
- • Network routes (BGP prefixes)
- • Registry information (ARIN, RIPE, APNIC, etc.)
Use Cases
- • Identify network and ISP owners
- • Security and threat intelligence
- • BGP routing analysis
- • Network troubleshooting
- • Peering and transit research
ASN Lookup by IP
ASN Lookup by IP instantly identifies which autonomous system controls any IP address — revealing the network operator, BGP routing data, and announced IP prefix.
Find the ASN for any IP address instantly. This helps you identify which network owns the IP and how traffic is routed using BGP (Border Gateway Protocol). Use this tool to investigate hosting infrastructure, trace network ownership for security research, or verify which network operator controls a specific IP block. Each IP prefix is announced by exactly one ASN in the global BGP routing table.
Read moreWhat is an ASN
An ASN (Autonomous System Number) is a globally unique number assigned to a network operator. It identifies who controls a block of IP addresses and manages BGP routing for those addresses.
An Autonomous System Number (ASN) is a unique identifier assigned to a network. It is used in BGP to control how traffic flows across the internet. Regional Internet Registries (RIRs) — ARIN, RIPE NCC, APNIC, LACNIC, and AFRINIC — assign ASNs to network operators including ISPs, cloud providers, universities, and large enterprises. Each ASN may control thousands of IP addresses across multiple IP prefixes.
Read moreWhat is BGP
BGP (Border Gateway Protocol) connects autonomous systems worldwide. It is the routing protocol that controls how traffic moves between networks on the global internet.
BGP (Border Gateway Protocol) is the core routing protocol of the internet. It determines how data moves between networks worldwide. Each autonomous system (ASN) uses BGP to announce its IP prefixes to neighboring networks, building the global routing table. BGP path selection uses attributes like AS path length and local preference to determine the optimal route between any two points on the internet.
Read moreASN vs IP Address vs Domain
ASN = network operator. IP address = device or server. Domain = human-readable name. These three layers form the foundation of internet addressing and routing.
An Autonomous System Number (ASN) identifies a network operator — a company or organization that controls a group of IP prefixes and manages BGP routing for those addresses. An IP address identifies a specific device or server within that network. A domain name is a human-readable label (like google.com) that resolves to one or more IP addresses via DNS. Understanding this hierarchy — domain → IP → ASN → BGP — is fundamental to network security analysis and internet infrastructure research.
Identify any IP owner, ASN, or BGP network instantly.
Try ASN Lookup nowASN Lookup for Network Analysis & Security
Network engineers, security researchers, and infrastructure teams rely on ASN data daily. Use ASN Lookup for network analysis — map IP blocks to their operators and understand BGP routing topology. For security investigation, identify whether an IP belongs to a known hosting provider, VPN, or botnet-associated ASN. Infrastructure visibility teams track which ASNs host their assets to detect unauthorized cloud usage. Threat intelligence platforms use ASN reputation to block malicious network ranges before attacks reach your infrastructure.
Popular ASN Lookups
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How to Use This Tool
- What to Enter
- Enter an IP address or ASN number (e.g. AS15169 or 8.8.8.8) to find network operator details, BGP-announced prefixes, and peering information.
- What You Get
- Shows ASN number, organization name, country, registry (ARIN, RIPE, APNIC), IPv4 and IPv6 prefix announcements, total IP count, and peering details.
How to Interpret Results
The ASN identifies the BGP network operator. Large prefix counts indicate major providers. The registry (ARIN, RIPE, APNIC, LACNIC, AFRINIC) reflects the regional internet registry that manages the ASN. ASN reputation affects IP trustworthiness — ASNs associated with spam or abuse networks are flagged by threat intelligence providers.
Common Issues & Troubleshooting
Some IPs may show a different ASN than the domain owner due to IP transit or CDN hosting arrangements. AS-SET data may be outdated. Private/internal IPs (RFC 1918) do not have ASN assignments.