ALERT

[FREE DEMO] Deploy Your Enterprise Cloud in Minutes

Autonomous System Number (ASN)

Definition - What does Autonomous System Number (ASN) mean?

An autonomous system number (ASN) is a unique number that's available globally to identify an autonomous system and which enables that system to exchange exterior routing information with other neighboring autonomous systems.

The number of autonomous system numbers is limited. For autonomous system numbers to be assigned, current guidelines need the network to be multi-homed and have a unique routing policy. Autonomous system numbers can be assigned only through a request to the local Internet registry.

Techopedia explains Autonomous System Number (ASN)

Autonomous system numbers range from 1 to 64,511. When an ASN is needed, the next highest unused number is assigned. The American Registry for Internet Numbers manages IP address allocations and assignments; it is also the authority for assigning and tracking ASNs. The current ASN allocation is based on 16-bit ASNs, which could be exhausted in the near future. Other alternate approaches like 32-bit ASN approaches are currently being explored.

There are two types of autonomous system numbers: public and private. A public autonomous system number is used when the system is exchanging routing information on the public Internet with other autonomous systems. A private autonomous system number is used only if the autonomous system is communicating with a single provider via Border Gateway Protocol. In the case of a public autonomous system number, the routes will be visible on the Internet, whereas in the case of private autonomous system numbers, the routes will not be visible on the Internet.

Techopedia Deals

Connect with us

Techopedia on Linkedin
Techopedia on Linkedin
Tweat cdn.techopedia.com
"Techopedia" on Twitter


'@Techopedia'
Sign up for Techopedia's Free Newsletter!

Email Newsletter

Join thousands of others with our weekly newsletter

Resources
The 4th Era of IT Infrastructure: Superconverged Systems
The 4th Era of IT Infrastructure: Superconverged Systems:
Learn the benefits and limitations of the 3 generations of IT infrastructure – siloed, converged and hyperconverged – and discover how the 4th...
Approaches and Benefits of Network Virtualization
Approaches and Benefits of Network Virtualization:
Businesses today aspire to achieve a software-defined datacenter (SDDC) to enhance business agility and reduce operational complexity. However, the...
Free E-Book: Public Cloud Guide
Free E-Book: Public Cloud Guide:
This white paper is for leaders of Operations, Engineering, or Infrastructure teams who are creating or executing an IT roadmap.
Free Tool: Virtual Health Monitor
Free Tool: Virtual Health Monitor:
Virtual Health Monitor is a free virtualization monitoring and reporting tool for VMware, Hyper-V, RHEV, and XenServer environments.
Free 30 Day Trial – Turbonomic
Free 30 Day Trial – Turbonomic:
Turbonomic delivers an autonomic platform where virtual and cloud environments self-manage in real-time to assure application performance.