Skip to content
Get Started
G2G2
4.7/5
Excellent
Trustpilot

What Is an ASN (Autonomous System Number)?

An ASN (Autonomous System Number) is the number that identifies one network on the internet, such as a home broadband provider, a mobile carrier or a cloud host. Every public IP address is announced by an ASN, and the ASN tells a website what kind of network a visitor is coming from.

Try Now for $4.99Continue with Google
  • Session Control
  • High Speed
  • Privacy First
Best fit for ASNStatic ISP Proxiesfrom$0.75/IP
how it works

How ASNs work

The internet is a network of networks. Each one that runs its own routing policy is an autonomous system, and a regional internet registry (ARIN in North America, RIPE NCC in Europe, APNIC in Asia-Pacific) gives it a unique number, for example AS7922 for Comcast. The network then announces its IP ranges to its neighbours with BGP, the protocol that tells routers which network can reach which addresses.

Because those announcements are public, anyone can map an IP address to the ASN that announces it, along with the organisation name behind it. That lookup is free, instant and hard to fake, which is why almost every anti-fraud and anti-bot system starts with it.

  • 1

    Consumer ISP

    Typical owner
    Comcast, Cox, Frontier, AT&T
    How websites tend to treat it
    Ordinary household traffic; highest trust
  • 2

    Mobile carrier

    Typical owner
    Phone networks
    How websites tend to treat it
    High trust; many real users share each IP through CGNAT
  • 3

    Hosting / cloud

    Typical owner
    AWS, Google Cloud, OVH, DigitalOcean
    How websites tend to treat it
    Servers, not people; challenged or blocked first on strict sites
why it matters

Why the ASN matters for proxy users

The ASN is the single biggest difference between proxy types. A datacenter proxy is announced by a hosting ASN, so a site can tell from one lookup that the visitor is a server. An ISP proxy is announced by a consumer internet provider's ASN, so it looks like a home connection while running on fast server hardware.

When you buy ISP or residential proxies, check the ASN of a few IPs before you scale up. The organisation name should be a real consumer carrier, not a hosting company or an unknown reseller.

ASN: what it means for you
  • Paste an IP into the IP lookup tool to see its ASN, organisation and registry data.
  • Use the proxy checker to test a whole list and see the ISP behind each working proxy.
  • Expect a fixed ASN on a static ISP proxy for as long as you hold the IP; a rotating pool changes ASN as the exit IP changes.
try it

Look up an ASN from the command line

Team Cymru's public whois service maps any IP to its ASN in one query:

CleanProxies static ISP proxies are dedicated IPs announced by US carrier ASNs such as Frontier, AT&T, Comcast, Cox, RCN and T-Mobile, as low as $0.75 per IP with unlimited bandwidth.

IP to ASN lookupShell
whois -h whois.cymru.com " -v 8.8.8.8"
# AS    | IP      | BGP Prefix | CC | Registry | Allocated  | AS Name
# 15169 | 8.8.8.8 | 8.8.8.0/24 | US | arin     | 2023-12-28 | GOOGLE - Google LLC, US

Static ISP proxies from $0.75/IP

The CleanProxies proxy that fits best here, with a $4.99 trial to test it first.

Static ISP Proxies

Best fit

Dedicated IPs on US carrier ASNs with unlimited bandwidth and threads, never shared.

starting from$0.75/IP

Dedicated static IPs registered to US and Canadian ISPs. The address stays the same for as long as you hold it, with unlimited bandwidth and HTTP(S) or SOCKS5 access.

Buy NowSee Static ISP Proxies features

Go deeper

Guides from the blog

Setup guides and best practices from the CleanProxies blog.

Get the latest insightsAll Blogs

Related terms

Terms that come up alongside ASN.

All glossary terms

ASN FAQs

Straight answers about ASN.

Use an IP lookup tool or a whois query against a BGP data source such as Team Cymru. Both return the ASN that announces the IP and the organisation behind it, for example AS7922 Comcast.

Got more questions?All FAQs