AS4538: the ERX-CERNET-BKB China Education and Research Network Center network

AS4538 is an internet Autonomous System operated by ERX-CERNET-BKB China Education and Research Network Center (China). Here is what that means and why this number may show up when you investigate a connection on your network.

What is AS4538?

An Autonomous System (ASN) is a block of networks under a single control with its own routing policy on the internet. The number AS4538 was assigned to ERX-CERNET-BKB China Education and Research Network Center by an RIR (regional internet registry). All traffic entering or leaving that network is announced under this number.

Reach on the internet

AS4538 currently announces 888 IPv4 block(s), totaling about 16.4 million addresses (16,446,976 in all), registered in China. Services from ERX-CERNET-BKB China Education and Research Network Center are reached through these addresses.

What it means to see AS4538 on your network

When you investigate where a connection from your computer or phone comes from (or goes to), you may find AS4538. That means the other end sits on the ERX-CERNET-BKB China Education and Research Network Center network (China). 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

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