What is an Autonomous System Number (ASN)
Autonomous System Number (ASN) is a globally unique identifier that defines a group of one or more IP prefixes run by one or more network operators that maintain a single, clearly-defined routing policy. These groups of IP prefixes are known as autonomous systems. The ASN allows the autonomous systems to exchange routing information with other autonomous systems.
Network operators across the world need Autonomous System Numbers to control routing within their networks as well as exchange routing information with other network operators - example; Internet Service providers.
Types of ASNs
There are two types of ASNs, namely private and public ASN.
- A private ASN can be used for a system which is communicating via BGP (Border Gateway Protocol) with one provider
- A public ASN is needed to exchange information over the Internet.
ASNs are available in two formats; 2-byte ASN and 4-byte ASN
- A 2-byte ASN is a 16-bit number which can provide up to 65,536 ASNs (0 to 65,535). The Internet Assigned Numbers Authority (IANA) has reserved 1,023 (64,512 to 65,534) from the mentioned range for private use. (RFC 6996 - Autonomous System (AS) Reservation for Private Use)
- A 4-byte ASN is a 32-bit number which provides 232, that is 4,294,967,296 ASNs (0 to 4,294,967,295). IANA has reserved 4,200,000,000 to 4,294,967,294 for private use (94,967,295 ASNs). (RFC 6793 – BGP Support for Four-Octet AS Number Space)
IANA and the RIRs will cease to make any distinction between 2-byte only and 4-byte only ASNs and will operate ASN allocations from an undifferentiated 4-byte ASN allocation pool as per the policy documented here.
Benefits of having a public AS Number
- Network operators can have their own network identity internally and externally
- The capability of establishing own Border Gateway Protocol with a public ASN
- Ability to directly peer with Internet Exchange Points
- Network operators can have better control of the traffic
- Flexible Network Management
- IP Address portability is one of the major benefits of using own IP address and ASN
Requesting Autonomous System Number (ASN) from AFRINIC
1) Application Process
- Case 1: Non-AFRINIC resource member requesting for an ASN -
Applicants who wish to become an AFRINIC member to request for an Autonomous System Number should go through the process as mentioned at 'How to become an AFRINIC Member', the link provides guidance and detailed requirements as to how to become an AFRINIC Member to get IP resources.
- Case 2: Existing AFRINIC resource member requesting for an ASN
AFRINIC members should go through the MYAFRINIC portal to request for their first or additional AS Number(s) under Resources > AS Numbers
AFRINIC has three policies under which an AS Number can be requested:
Autonomous System Number can be used for varying use cases and AFRINIC has different policies that provide guidance on assignment of these ASN’s based on certain use cases.
- Policy from ASN management in the AFRINIC region - AFRINIC assigns AS Numbers for Autonomous Systems located in the AFRINIC service region and accepts requests from Local Internet Registries (LIRs), non-LIR's members and non-members.
CPM Section 7.4: Eligibility for an AS Number Assignment - https://www.afrinic.net/policy/manual#ASN-Eligibility
- Anycast resource assignments in the AFRINIC region. - This policy allows an organization to receive an AS Number purely for anycast or GPRS Roaming Exchange (GRX) usage.
CPM Section 12.0: Anycast Resource Assignments - https://www.afrinic.net/policy/manual#Anycast
- Resource Reservations from IXPs - AFRINIC has an existing policy to make allocations to IXPs which reserves a set of 2-byte ASNs between 0 - 65,535 for use by IXPs, for IXP BGP Route Servers. CPM Section 11.0: Resource Reservations for Internet Exchange Points - https://www.afrinic.net/policy/manual#Resource-Reservations-IXPa
- AFRINIC has the Contractual Obligation Check (COC) which supervenes prior to evaluating a request, more details can be found here.
- ASNs requests are evaluated as per the above - mentioned sections of the Consolidated Policy Manual which are summarised below:
- The requestor should interconnect (including peering) with more than one AS
- The AS Number should be used to implement a unique routing policy or demonstrate a technical need for a coordinated globally unique ASN.
An organization will also be eligible if it can demonstrate that it will meet the above criteria upon receiving an ASN (or within the following six months).
To help ease the evaluation process, we provide below several types of documentation that may be required.
|Policy||Requirements for evaluation|
Policy from AFRINIC management in the AFRINIC Region
Eligibility for an AS Number Assignment
Anycast resource assignments in the AFRINIC Region
CPM Section 11.0: Resource Reservations for Internet Exchange Points
Resource Reservations from IXPs
CPM Section 12.0: Anycast Resource Assignments https://www.afrinic.net/policy/manual#Anycast
Upon conclusion of the evaluation of ASN request(s) in accordance with the policies currently in place at AFRINIC, a one-off assignment fee of 400USD shall be invoiced per AS Number according to the fees schedule. More details about the billing schedule can be found at https://afrinic.net/membership/cost
Note: An End User which is assigned an ASN and no other resource type shall pay USD 400 initial assignment fees in addition to a yearly membership of USD 50 which is referred to as maintenance fee in the Policy.
AFRINIC offers discounts to its members based on the criteria below. The discounts are only attributed after AFRINIC Hostmasters have been able to confirm the member eligibility. In this regard, resource members may be requested to provide more documentation.
Educational Institutions - As per the current fees structure, educational institutions such as universities and Research & Education Networks (RENs) may be eligible for a 50% discount on the one-off assignment fee exclusively for not-for-profit academic or research activities.
Critical Infrastructure - AFRINIC offers a 100% discount to organisations requesting ASNs for the purpose of Critical Infrastructure.
Note: The AFRINIC membership fees schedule for these two categories can be viewed under section 5 here.