What are Autonomous System Numbers?

An Autonomous System Number (ASN) is a short numerical key assigned to a computer network to allow other computers to connect. These keys are leased from a Regional Internet Registry such as ARIN or RIPE.

There are two main types of Autonomous System Numbers, they are:

  • A public ASN.
  • A private ASN.

Public Autonomous System Numbers

An ASN in the public range is globally available and announced via an Internet Service Provider, Internet Exchanging Point, or Border Gateway Point.

These systems will often share a single system number, provided that all the IP addresses are using a shared routing policy.

Identifiers such as the ASN help different systems to communicate with each other and serve to group IP addresses.

Private Autonomous System Numbers

An ASN in the private range is never globally available and is used by Internet Service Providers for private networks.

These are becoming increasingly rare and do not apply to Search Engine Optimisation. The world wide web is a public network, and thus all websites are served globally.

How can I check Autonomous System Numbers?

For the most part, you will never need to check your Autonomous System Numbers. It is something that your service provider will need to worry about, but not something for which you should be concerned.

Furthermore, since the internet is still using IPv4, which is exhausted – the chances are that you will have multiple websites in the same public ASN. However, if you’re receiving link building, and the website’s look suspicious, you may want to check these details.

By using the InfoByIP ASN Bulk Check, you can quickly determine if domains are on the same network. The chances that your link provider accidentally got lots of backlinks from the same system, all pointed towards you and with similar themes is very slim.

If this is you, then you may wish to consider using a different service. These links are most likely privately owned and manipulative.

List of Autonomous System Numbers

How to improve Autonomous System Numbers?

These are unlikely to be a ranking factor and thus not something with which you should generally be concerned. However, if you suspect that there is link manipulation, you may wish to diversify link sources.

If you’re looking to host a private blog network, which is a form of link building, then you may want to consider the autonomous system numbers.

The best way to maintain diversity would be to place links on small servers owned by different companies. Preferably, these servers should be geographically spread.