As your online presence grows, you may start hearing more about advanced networking topics. One term that often comes up for scaling businesses, ISPs, and hosting providers is the "Autonomous System Number," or ASN. While it sounds complex, understanding if you need one is a critical step in building a resilient and professional network.
This guide will demystify the ASN and provide a clear checklist to help you determine if it's the right time for your business to take this important step.
What is an Autonomous System Number (ASN)?
Think of the internet as a massive network of interconnected networks. An Autonomous System (AS) is a large network or group of networks that has a single, unified routing policy. Each AS is assigned a unique number—its ASN—which it uses to announce its IP address prefixes to other networks via the Border Gateway Protocol (BGP). In simple terms, an ASN is your network's official, globally unique ID. It tells the rest of the internet, "Here I am, and here is how you can reach me."
When Do You Need an ASN? The Checklist
Most businesses don't need an ASN. If you only have one internet provider and don't manage your own IP addresses, your provider handles all the routing for you. However, you should seriously consider acquiring an ASN if you can answer "yes" to one or more of the following questions:
- Are you multi-homed or planning to be? Multi-homing means you are connected to two or more different internet providers (ISPs) simultaneously. This is the most common reason to get an ASN. With your own ASN, you can announce your IP addresses to both providers, creating true network redundancy. If one provider has an outage, traffic can automatically reroute through the other, keeping your services online.
- Do you want to control your own routing policies? An ASN gives you control. You can decide which provider is your primary path and which is your backup, or even route specific types of traffic over different links for performance or cost reasons. This level of control is impossible when you are simply using your provider's IP space.
- Do you have your own Provider Independent (PI) IP addresses? If you have your own PI IP address block (either IPv4 or IPv6), you need an ASN to announce it to the internet. PI space is portable, meaning it belongs to you, not your provider. An ASN is the mechanism that allows you to make that portable space reachable from anywhere.
- Do you want to establish direct peering with other networks? Peering is when two networks agree to exchange traffic directly, often without cost. This can improve performance and reduce latency for your users. To peer with major networks at an Internet Exchange Point (IXP), you must have your own ASN.
The Primary Benefits of Having Your Own ASN
If you fit the criteria above, acquiring an ASN offers significant advantages that can directly impact your bottom line and service quality:
- Increased Uptime and Reliability: True multi-homing redundancy is the number one benefit. It protects your business from provider-specific outages, ensuring maximum availability for your customers.
- Improved Performance: By controlling your routing, you can choose the most efficient path for your data, reducing latency and improving the user experience.
- Provider Independence: With your own ASN and PI IP space, you are no longer locked into a single provider. You can add, remove, or change ISPs without having to re-number your entire network, which is a massive and costly undertaking.
- Enhanced Brand Reputation: For tech companies, ISPs, and hosting providers, having your own ASN signals a high level of technical maturity and professionalism. It shows you are a serious player on the internet.
Ready to Take the Next Step?
Acquiring an ASN involves a formal application process with a Regional Internet Registry like RIPE NCC. The requirements are strict, but the benefits for a scaling network are undeniable. As an official RIPE LIR, NordicVM is perfectly positioned to guide you through this process. We can help you prepare the necessary documentation, justify your technical need, and manage the application from start to finish.
If you answered yes to any of the items on our checklist, contact our LIR services team today for a free consultation. We can help you build a more resilient and professional network for the future.