AS213990: the AOFB network

AS213990 is an internet Autonomous System operated by AOFB (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 AS213990?

An Autonomous System (ASN) is a block of networks under a single control with its own routing policy on the internet. The number AS213990 was assigned to AOFB by an RIR (regional internet registry). All traffic entering or leaving that network is announced under this number.

Reach on the internet

AS213990 currently announces 11 IPv4 block(s), totaling about 2.8 thousand addresses (2,816 in all), registered in the United Kingdom. Services from AOFB are reached through these addresses.

What it means to see AS213990 on your network

When you investigate where a connection from your computer or phone comes from (or goes to), you may find AS213990. That means the other end sits on the AOFB 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.