AS57948: the COBALT IPWorks network

AS57948 is an internet Autonomous System operated by COBALT IPWorks (Belgium). Here is what that means and why this number may show up when you investigate a connection on your network.

What is AS57948?

An Autonomous System (ASN) is a block of networks under a single control with its own routing policy on the internet. The number AS57948 was assigned to COBALT IPWorks by an RIR (regional internet registry). All traffic entering or leaving that network is announced under this number.

Reach on the internet

AS57948 currently announces 4 IPv4 block(s), totaling about 2.6 thousand addresses (2,560 in all), registered in Belgium. Services from COBALT IPWorks are reached through these addresses.

What it means to see AS57948 on your network

When you investigate where a connection from your computer or phone comes from (or goes to), you may find AS57948. That means the other end sits on the COBALT IPWorks network (Belgium). 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.