AS200454: the Tomas Oliveira Valente Leite de Castro network

AS200454 is an internet Autonomous System operated by Tomas Oliveira Valente Leite de Castro (Portugal). Here is what that means and why this number may show up when you investigate a connection on your network.

What is AS200454?

An Autonomous System (ASN) is a block of networks under a single control with its own routing policy on the internet. The number AS200454 was assigned to Tomas Oliveira Valente Leite de Castro by an RIR (regional internet registry). All traffic entering or leaving that network is announced under this number.

Reach on the internet

AS200454 currently announces 2 IPv4 block(s), totaling 512 addresses (512 in all), registered in Portugal. Services from Tomas Oliveira Valente Leite de Castro are reached through these addresses.

What it means to see AS200454 on your network

When you investigate where a connection from your computer or phone comes from (or goes to), you may find AS200454. That means the other end sits on the Tomas Oliveira Valente Leite de Castro network (Portugal). 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.