An ASN is a number that is used to define a group of routing prefixes that maintains a unique routing policy that differs from the routing policies of network border peers. ISPs use ASNs to control routing within their networks and to exchange routing information with other ISPs.  AS numbers (along with BGP) help routers and networks to identify where information comes from and where it should go outside a particular ISP’s network.  A public ASN is needed for an autonomous system to exchange routing information with two or more autonomous systems on the public Internet.  Here’s how to secure your own:

  1. Go to and create an ARIN online account.  This is your personal account so use your own email address and password.


  1. Next, you need to create one or more Point(s) of Contact (POC).  These are “role” accounts used for ARIN to interact with roles within an organization.  An example is the Abuse account where other admins should direct queries related to abuse of network resources originating or affecting your network.  Make these role accounts in your email directory as well so that they can remain flexible.


  1. Third, you will want to create an ARIN Organization (Org ID). This will represent your company or legal entity.  This Org ID will in turn link to the POC records you created in step 2 above.


  1. Now you have the basic records set up in ARIN are you are ready to begin the ASN application process.  First, do you have signed contracts with two distinct network providers (ISPs)?  If so, good.  Gather up all the paperwork from your network providers.  If not, hold up, consider if you need an ASN at all.  Without two providers, there is little need for you to run BGP.  As such, you will have a harder time getting help from ARIN.


  1. With all your paperwork in order, login to your ARIN account and select “Request Resources.’  Navigate to: review the requirements.  You will be following section for Multi-Homed so you’ll need:
  •   the exterior gateway protocol to be used: BGP
  •  the IP addresses currently in use on your network.  List *every* IP number you currently use.  Web servers, mail servers, office gateways, whatever you can come up with.
  •  provide verification (use the signed contracts you gathered in step 4 above).  List your providers AS numbers.
  •  If this is a secondary AS for your organization, you’ll need to provide additional details as to why you need a new number.


  1.  ARIN will issue you a ticket number to track your application.  Once this is approved you need to pay the registration fee.  ARIN charges $500 USD to register each AS number.  You will see an additional fee if you obtain IPv4 address space from ARIN as well.


  1.  Complete and sign the Registration Services Agreement (RSA) linked here:


  1.  Assignment.  ARIN will designate your new ASN and you are ready to go forth

into the world of BGP.