CC2ASN

Country code in.
Networks out.

A lookup service for AS numbers and prefixes belonging to any given country in the world. Simply provide country codes as input and you’ll get all ASNs, IPv4 or IPv6 addresses registered to that country.

Build a query

api.cc2asn.com/ALL/IS

IS Iceland
AS numbers
86
IPv4 prefixes
176
IPv6 prefixes
72
5.23.64.0/19
31.15.112.0/21
31.43.172.0/23
31.209.136.0/21
31.209.144.0/20
31.209.192.0/18
37.152.64.0/21
37.156.68.0/24
37.205.32.0/21
37.228.128.0/24
37.228.129.0/24
45.135.209.0/24
45.151.214.0/24
46.22.96.0/20
46.28.152.0/21
46.182.184.0/21
46.239.192.0/18
62.145.128.0/19
77.73.33.0/24
78.40.248.0/21
79.171.96.0/21
80.248.16.0/20
  • Dailyfive registries
  • Free100 queries daily
  • curl or whoisno sign-up

Straight from the registries

AFRINIC, APNIC, ARIN, LACNIC and RIPE NCC publish who holds which numbers. CC2ASN fetches each file daily, checks its MD5 sum and files every record by country.

  1. One line per allocation

  2. The country is the key

  3. Addresses become a prefix

  4. Filed under NO, IPv4

delegated-ripencc-extended-latest

ripencc|ES|ipv4|2.136.0.0|524288|20101105|allocated
ripencc|IR|ipv4|2.144.0.0|262144|20101022|allocated
ripencc|NO|ipv4|2.148.0.0|262144|20101022|allocated
ripencc|ES|ipv4|2.152.16.0|4096|20101103|allocated
ripencc|ES|ipv4|2.152.42.0|512|20101103|allocated
Country
NO, Norway
Type
IPv4
Addresses
262,144 from 2.148.0.0, a /14

2.148.0.0/14in NO_IPV4

The words, briefly

AS number

An autonomous system is a group of networks run under one routing policy, usually by an internet provider, a company or a university. Its number, the ASN, is a 16- or 32-bit integer, written plain (65551) or dotted (1.15).

Read more

Prefix

A block of IP addresses, also called an IP range or IP block, written as its first address, a slash and the number of fixed bits: 192.0.2.0/24 holds 256 addresses. Registries list IPv4 space as a start and a count, which CC2ASN turns into prefixes. IPv6 space is listed as a prefix already.

Read more

Country code

The two-letter ISO 3166-1 alpha-2 code the registry has on file for the holder, such as NO for Norway. Territories have codes of their own: SJ for Svalbard and Jan Mayen, PS for Palestine.

Read more

Where it helps

Pick a use case to see how a country’s networks help.

Security

Networking

Research

Geo-blocking

Load a country’s IPv4 and IPv6 prefixes into a firewall set to block or allow the whole country in one rule.

Change one word, get the full list

Swap ASN for ALL and the same query returns Iceland's AS numbers and both prefix lists.

two letters

Any country code the registries use, in upper or lower case.

Build your query

All 249 ISO 3166-1 codes. A few territories have no registered networks and answer 404.

Records
Client
Format

Your command

curl https://api.cc2asn.com/NO

Every AS number registered to NO, one per line.

Open answer

Query syntax
RecordsHTTP pathwhois, port 43
AS numbers/NOno
IPv4/IPV4/NOipv4 no
IPv6/IPV6/NOipv6 no
All/ALL/NOall no

Good to know

  • The registries' files are fetched every day and sorted by country. A lookup always returns the latest day.

  • No. It is the country the registry has on file for the holder. A network can be used anywhere; this is registration, not geolocation.

  • Nothing. Each person gets 100 queries a day and 30 a minute, with no account and no key.

  • No. The API serves the latest day only; dated paths answer 404.

  • You get a 404 with the path that was not found. Use the two-letter ISO 3166 codes the registries use.

  • Some whois clients stop on long answers. Send the same query with netcat: echo ipv4 dk | nc cc2asn.com 43