BGP Route Lookup
Look up an IP address or ASN in our collected BGP prefixes and origin ASNs
Usage
• Enter a public IPv4 or IPv6 address, or an ASN
• Shows the BGP routing prefix (CIDR) the IP belongs to
• Shows the origin AS number for each matching prefix
What BGP route lookup is for
This tool reads a current route snapshot from our own BGP collector. It returns the announced prefix covering a public IP and the origin ASN. An ASN query lists its observed prefixes. The result reflects only the collector's connected peers.
Use the result to check a prefix and its origin ASN, or compare observations after a network change. This tool does not currently expose the full AS path.
Frequently asked questions
What is an AS path?
The AS path is the list of Autonomous System Numbers that a BGP route traverses to reach the destination prefix. Each AS represents a network operated by a different organization. A shorter path generally means fewer handoffs and potentially lower latency.
Why might an IP not have a BGP route?
Private or reserved IP ranges (RFC 1918, loopback, link-local) are not announced in the global BGP table. Unallocated IPs also have no route. Only globally routed public IPs will return BGP route data.
How is BGP route lookup different from IP geolocation?
IP geolocation maps an IP to a physical location. This BGP lookup shows an observed routing prefix and its origin ASN.
What does the prefix (CIDR) tell me?
The prefix is the IP block that is announced to the global routing table by the originating AS. All IPs within that block are reachable via the same BGP route. Knowing the prefix helps you understand the scope of a network event or route change.