AS6389: the BELLSOUTH-NET-BLK network

AS6389 is an internet Autonomous System operated by BELLSOUTH-NET-BLK (the United States). Here is what that means and why this number may show up when you investigate a connection on your network.

What is AS6389?

An Autonomous System (ASN) is a block of networks under a single control with its own routing policy on the internet. The number AS6389 was assigned to BELLSOUTH-NET-BLK by an RIR (regional internet registry). All traffic entering or leaving that network is announced under this number.

Reach on the internet

AS6389 currently announces 171 IPv4 block(s), totaling about 4.4 million addresses (4,429,312 in all), registered in the United States. Services from BELLSOUTH-NET-BLK are reached through these addresses.

What it means to see AS6389 on your network

When you investigate where a connection from your computer or phone comes from (or goes to), you may find AS6389. That means the other end sits on the BELLSOUTH-NET-BLK network (the United States). 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.