AS25552: the GNB-AS Katowice-Poland-Velobank network

AS25552 is an internet Autonomous System operated by GNB-AS Katowice-Poland-Velobank (Poland). Here is what that means and why this number may show up when you investigate a connection on your network.

What is AS25552?

An Autonomous System (ASN) is a block of networks under a single control with its own routing policy on the internet. The number AS25552 was assigned to GNB-AS Katowice-Poland-Velobank by an RIR (regional internet registry). All traffic entering or leaving that network is announced under this number.

Reach on the internet

AS25552 currently announces 4 IPv4 block(s), totaling about 1 thousand addresses (1,024 in all), registered in Poland. Services from GNB-AS Katowice-Poland-Velobank are reached through these addresses.

What it means to see AS25552 on your network

When you investigate where a connection from your computer or phone comes from (or goes to), you may find AS25552. That means the other end sits on the GNB-AS Katowice-Poland-Velobank network (Poland). 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.