AS25098: the NETCALIBRE network

AS25098 is an internet Autonomous System operated by NETCALIBRE (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 AS25098?

An Autonomous System (ASN) is a block of networks under a single control with its own routing policy on the internet. The number AS25098 was assigned to NETCALIBRE by an RIR (regional internet registry). All traffic entering or leaving that network is announced under this number.

Reach on the internet

AS25098 currently announces 10 IPv4 block(s), totaling about 25.9 thousand addresses (25,856 in all), registered in the United Kingdom. Services from NETCALIBRE are reached through these addresses.

What it means to see AS25098 on your network

When you investigate where a connection from your computer or phone comes from (or goes to), you may find AS25098. That means the other end sits on the NETCALIBRE 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.