AS21500: the TNS-AS network
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Testar grátis 14 dias →AS21500 is an internet Autonomous System operated by TNS-AS (Ukraine). Here is what that means and why this number may show up when you investigate a connection on your network.
What is AS21500?
An Autonomous System (ASN) is a block of networks under a single control with its own routing policy on the internet. The number AS21500 was assigned to TNS-AS by an RIR (regional internet registry). All traffic entering or leaving that network is announced under this number.
Reach on the internet
AS21500 currently announces 14 IPv4 block(s), totaling about 9 thousand addresses (8,960 in all), registered in Ukraine. Services from TNS-AS are reached through these addresses.
What it means to see AS21500 on your network
When you investigate where a connection from your computer or phone comes from (or goes to), you may find AS21500. That means the other end sits on the TNS-AS network (Ukraine). 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.
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Perguntas frequentes
Who owns AS21500?
AS21500 is assigned to TNS-AS, registered in Ukraine.
What is an ASN (Autonomous System)?
It is a unique number identifying a network with its own routing policy on the internet. RIRs (regional registries) assign these numbers to carriers, ISPs and companies.
How many IP addresses does AS21500 control?
AS21500 currently announces about 9 thousand routed IPv4 addresses.