AS8220: the COLT COLT Technology Services Group Limited network

AS8220 is an internet Autonomous System operated by COLT COLT Technology Services Group Limited (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 AS8220?

An Autonomous System (ASN) is a block of networks under a single control with its own routing policy on the internet. The number AS8220 was assigned to COLT COLT Technology Services Group Limited by an RIR (regional internet registry). All traffic entering or leaving that network is announced under this number.

Reach on the internet

AS8220 currently announces 148 IPv4 block(s), totaling about 1.5 million addresses (1,489,407 in all), registered in the United Kingdom. Services from COLT COLT Technology Services Group Limited are reached through these addresses.

What it means to see AS8220 on your network

When you investigate where a connection from your computer or phone comes from (or goes to), you may find AS8220. That means the other end sits on the COLT COLT Technology Services Group Limited 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.