AS43991: the VORONEZHTELECOM-AS network

AS43991 is an internet Autonomous System operated by VORONEZHTELECOM-AS (Russia). Here is what that means and why this number may show up when you investigate a connection on your network.

What is AS43991?

An Autonomous System (ASN) is a block of networks under a single control with its own routing policy on the internet. The number AS43991 was assigned to VORONEZHTELECOM-AS by an RIR (regional internet registry). All traffic entering or leaving that network is announced under this number.

Reach on the internet

AS43991 currently announces 18 IPv4 block(s), totaling about 5.1 thousand addresses (5,120 in all), registered in Russia. Services from VORONEZHTELECOM-AS are reached through these addresses.

What it means to see AS43991 on your network

When you investigate where a connection from your computer or phone comes from (or goes to), you may find AS43991. That means the other end sits on the VORONEZHTELECOM-AS network (Russia). 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.