AS16204: the AS44574 AS44574 network

AS16204 is an internet Autonomous System operated by AS44574 AS44574 (the United Kingdom). Here is what that means and why this number may show up when you investigate a connection on your network.

What is AS16204?

An Autonomous System (ASN) is a block of networks under a single control with its own routing policy on the internet. The number AS16204 was assigned to AS44574 AS44574 by an RIR (regional internet registry). All traffic entering or leaving that network is announced under this number.

Reach on the internet

AS16204 currently announces 1 IPv4 block(s), totaling 256 addresses (256 in all), registered in the United Kingdom. Services from AS44574 AS44574 are reached through these addresses.

What it means to see AS16204 on your network

When you investigate where a connection from your computer or phone comes from (or goes to), you may find AS16204. That means the other end sits on the AS44574 AS44574 network (the United Kingdom). 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.