AS21221: the INFOPACT-AS The Netherlands network

AS21221 is an internet Autonomous System operated by INFOPACT-AS The Netherlands (the Netherlands). Here is what that means and why this number may show up when you investigate a connection on your network.

What is AS21221?

An Autonomous System (ASN) is a block of networks under a single control with its own routing policy on the internet. The number AS21221 was assigned to INFOPACT-AS The Netherlands by an RIR (regional internet registry). All traffic entering or leaving that network is announced under this number.

Reach on the internet

AS21221 currently announces 18 IPv4 block(s), totaling about 100.6 thousand addresses (100,608 in all), registered in the Netherlands. Services from INFOPACT-AS The Netherlands are reached through these addresses.

What it means to see AS21221 on your network

When you investigate where a connection from your computer or phone comes from (or goes to), you may find AS21221. That means the other end sits on the INFOPACT-AS The Netherlands 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.