AS57866: the FUSIX-AS network

AS57866 is an internet Autonomous System operated by FUSIX-AS (the Netherlands). Here is what that means and why this number may show up when you investigate a connection on your network.

What is AS57866?

An Autonomous System (ASN) is a block of networks under a single control with its own routing policy on the internet. The number AS57866 was assigned to FUSIX-AS by an RIR (regional internet registry). All traffic entering or leaving that network is announced under this number.

Reach on the internet

AS57866 currently announces 15 IPv4 block(s), totaling about 9.7 thousand addresses (9,728 in all), registered in the Netherlands. Services from FUSIX-AS are reached through these addresses.

What it means to see AS57866 on your network

When you investigate where a connection from your computer or phone comes from (or goes to), you may find AS57866. That means the other end sits on the FUSIX-AS network (the Netherlands). It can be legitimate — a cloud service, an ISP, a CDN — or an unexpected connection worth checking.

How to see every connection and network your devices reach

Tracing one connection's ASN at a time is tedious. Sentinela, by PC Monitor, maps the devices on your network, shows what is exposed to the internet and helps flag suspicious connections and devices — running on your Windows. Meet Sentinela.