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What it is
An ASN (Autonomous System Number) identifies an autonomous system in BGP. It helps analyze routes and providers.
How it works
Find an ASN by IP or number. Review announced prefixes, upstreams and geography.
Examples
- ASN prefixes: the list of announced networks.
- Upstream/Peers: transit providers and BGP neighbors.
Limitations & notes
Announcements change dynamically. Data refresh can lag.
FAQ
- Why use ASN? Tracing, route analysis and ownership checks.
- Are there private ASNs? Yes, reserved ranges for internal use.