Beta: This tool is still in active development!
Please note the tool is still in active development. Everything is still subject to change, and I am still
adding info to the database. Any kind of feedback would be greatly appriciated! I'm reachable at
iamrootdottech(a)gmail.com. Thanks in advance!
Using the ASN database tool, you can search for information on IP addresses,
CIDR-ranges and the associated ASN’s.
The tool allows you to
- Look for a specific ASN's
- Search the ASN database using text-search
- Search for announched prefixes using specific IP's or CIDR ranges
The tool will return information on
- Any ASN - all basic information regarding the ASN, such as name and organisation
- Any prefix - the basic prefix information itself, info on who is announcing it and so forth
Possible uses of the ASN database
- If you need to contact the ASN responsible for a specific IP adress (this includes
abuse contacts as well)
- If you would like to figure out, who is operating a specific IP adress
For a quick introduction, try out these ASN database lookups:
ASN's named 'amazon.com'
Lookup of AS7018
Lookup of 18.104.22.168
What is an ASN / Autonomous System Number?
An Autonomous System Number (ASN) is a unique number that is assigned to an organization that operates a network using the Border Gateway Protocol (BGP) to exchange routing information with other networks on the Internet. An ASN is used to identify an autonomous system (AS), which is a collection of routers and networks operated by a single organization, and that shares a common routing policy.
The ASN is a 32-bit integer number that ranges from 1 to 4,294,967,295. The ASN is used by BGP to identify the network that is originating a route and to determine the best path for traffic to take between networks. Each ASN is assigned a unique identifier, and this identifier is used to distinguish it from other ASNs on the Internet.
What are ASN's used for?
ASNs are used by BGP to identify the origin of a route and to determine the best path for traffic to take between networks. Each AS is assigned a unique ASN, which is used to identify the AS to other networks on the Internet. BGP uses AS paths, which are sequences of ASNs, to identify the path that traffic takes between networks.
When a network wants to announce a new route, they use BGP to advertise the route to their neighboring networks. The BGP advertisement includes the ASN of the originating network and the IP prefix that is being advertised. When another network receives the advertisement, it adds the ASN of the advertising network to the AS path and uses its own routing policy to determine whether to accept the route or not.
In summary, ASN and BGP are closely related. ASNs are used by BGP to identify the origin of a route and to determine the best path for traffic to take between networks. BGP uses AS paths, which are sequences of ASNs, to identify the path that traffic takes between networks.
Who assignes the Autonomous System Number?
ASNs are assigned by regional Internet registries (RIRs) such as the American Registry for Internet Numbers (ARIN), the Asia Pacific Network Information Centre (APNIC), the Réseaux IP Européens Network Coordination Centre (RIPE NCC), the Latin American and Caribbean Internet Addresses Registry (LACNIC), and the African Network Information Centre (AFRINIC).
What is the 'announced prefixes'?
An 'announced prefix' is a range of IP addresses that are assigned to an
organization or network (identified as the ASN) for use in routing traffic on the Internet.
An ASN that has been allocated an IP address prefix is responsible for announcing
that prefix to other networks using the Border Gateway Protocol (BGP).
This announcement includes the ASN of the organization and the IP address prefix that is