AS9183 CIAFS3

AS9183 (CIAFS3) is held by Robert Bosch GmbH, the Stuttgart-based engineering and technology group. The handle is an internal Bosch department code, not a company name — nothing about CIAFS3 tells you who this is, but the registry, the address space and the reverse DNS all agree. The AS is Bosch's corporate internet-access network.

What it's used for

This is a large enterprise network, and its shape is unmistakable. RIS sees 264 IPv4 prefixes covering 67,584 addresses, plus one IPv6 /32 (2a03:cc00::/32) — and only 2 observed BGP neighbours. That combination is the tell. A carrier holding 67k addresses would peer with hundreds of networks; two neighbours means Bosch buys transit from a small number of upstreams and announces its own space to them. It is a consumer of internet connectivity at very large scale, not a supplier of it.

The 264 prefixes are almost entirely /24s carved out of 139.15.0.0/16, Bosch's own legacy /16. Deaggregating a /16 into individual /24s is a well-known corporate pattern: a globally distributed company with sites, plants and regional egress points on several continents announces each site's block separately so traffic can be steered to the nearest exit and so a single site's space can be withdrawn without touching the rest.

Sampled reverse DNS lands on gwr3.fe.bosch.de — a gateway router under Bosch's own domain, exactly what you would expect at the edge of a corporate WAN.

Notable

• The AS exists to provide global internet access for Bosch worldwide; the registry contact sits in Stuttgart.
• 264 prefixes from essentially one /16 makes this AS a noticeable contributor to routing-table deaggregation for its size.
• The handle CIAFS3 is a good example of why an AS name is never evidence of identity.