AS17516: the NTTCOMWARE NTT COMWARE CORPORATION network

AS17516 is an internet Autonomous System operated by NTTCOMWARE NTT COMWARE CORPORATION (Japan). Here is what that means and why this number may show up when you investigate a connection on your network.

What is AS17516?

An Autonomous System (ASN) is a block of networks under a single control with its own routing policy on the internet. The number AS17516 was assigned to NTTCOMWARE NTT COMWARE CORPORATION by an RIR (regional internet registry). All traffic entering or leaving that network is announced under this number.

Reach on the internet

AS17516 currently announces 11 IPv4 block(s), totaling about 19.5 thousand addresses (19,456 in all), registered in Japan. Services from NTTCOMWARE NTT COMWARE CORPORATION are reached through these addresses.

What it means to see AS17516 on your network

When you investigate where a connection from your computer or phone comes from (or goes to), you may find AS17516. That means the other end sits on the NTTCOMWARE NTT COMWARE CORPORATION network (Japan). 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.