AS5606: the GTS-BACKBONE GTS Telecom network

AS5606 is an internet Autonomous System operated by GTS-BACKBONE GTS Telecom (Romania). Here is what that means and why this number may show up when you investigate a connection on your network.

What is AS5606?

An Autonomous System (ASN) is a block of networks under a single control with its own routing policy on the internet. The number AS5606 was assigned to GTS-BACKBONE GTS Telecom by an RIR (regional internet registry). All traffic entering or leaving that network is announced under this number.

Reach on the internet

AS5606 currently announces 101 IPv4 block(s), totaling about 91.6 thousand addresses (91,648 in all), registered in Romania. Services from GTS-BACKBONE GTS Telecom are reached through these addresses.

What it means to see AS5606 on your network

When you investigate where a connection from your computer or phone comes from (or goes to), you may find AS5606. That means the other end sits on the GTS-BACKBONE GTS Telecom network (Romania). 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.