An autonomous system is the unit networks use to route traffic between each other. A BGP ASN lookup for AS306 shows how United States Department of Defense (DoD) is registered, which IP prefixes are associated with the network, and which peers or upstreams appear in the available routing data.
The announced prefixes table helps you find IP prefixes by ASN and inspect CIDR blocks tied to the organization. The peering section shows neighboring networks it exchanges traffic with — upstreams sell it transit, while peers swap traffic directly. Together they describe both what this network reaches and how it connects.
Use ASN profiles for network owner lookup, incident triage, IP range review and provider research. Treat the data as routing context, not live outage monitoring; BGP changes can move faster than public lookup datasets.
An Autonomous System Number, or ASN, is a globally unique identifier for a network operator that controls one or more IP prefixes and exchanges routing information with other networks using BGP. Examples include AS15169 for Google and AS13335 for Cloudflare.
An ASN lookup shows the network owner, organization, RIR, registration details, country, abuse contact, IPv4 and IPv6 prefix counts, sample announced prefixes, and observed peer or upstream relationships when available.
Enter an ASN such as AS15169 or 15169. The prefix table lists sample IPv4 and IPv6 CIDR blocks associated with that autonomous system, plus counts that help estimate the network size.
An upstream, also called a transit provider, carries traffic to the wider internet. A peer exchanges traffic directly, often at an internet exchange. Both relationships help explain how an AS connects to other networks.
No. This ASN lookup summarizes routing and registration datasets available to the tool. It is useful for network owner lookup, prefix discovery, and routing context, but not a replacement for real-time BGP monitoring or outage detection.