ASN Converter & Ownership Lookup

Convert Autonomous System Numbers (ASNs) between ASPlain and ASDot notation, then immediately see the AS name, organisation, and a lightweight one-hop neighbour summary. This keeps the page fast for routing work while reducing the need to jump to multiple lookup tools.

This is especially handy when you are reading old peering notes, vendor documents, or route-policy snippets that mix ASPlain and ASDot notation and you want to normalize the value before doing anything deeper.

Why The Conversion Matters

Four-byte ASNs are often written in different ways depending on the tool or document you are looking at. ASPlain is easier for most automation and policy work, while ASDot still appears in older systems and operational references. Having both forms side by side avoids simple copy mistakes when you are preparing filters, incident notes, or customer communication.

How To Use The Ownership Context

The extra ownership and neighbour information is there to answer the next question that usually follows conversion: “who is this ASN, and does it broadly match the network I think I am dealing with?” The one-hop neighbour summary is not meant to replace a full routing investigation, but it is a quick way to tell whether an ASN looks familiar, unexpectedly isolated, or connected to the upstreams you would expect.

Important Limits

The surrounding data comes from public routing and registry views, so it should be treated as directional context rather than a contractual source of truth. An organisation name can lag behind operational reality, and neighbour visibility depends on what public collectors observe. Use this page to orient yourself quickly, then move to deeper BGP tooling if the decision matters.