AS10423 SPARTAN-NET

SPARTAN-NET is STELLAR Broadband, a Michigan fiber ISP founded in 2001 and

originally trading as Spartan Net in East Lansing. It sells gigabit and

multi-gigabit fiber Internet into apartment buildings, student housing and

mixed-use developments.

What it's used for

• Residential broadband delivered to multi-dwelling units (MDUs): student housing around Michigan State, plus multifamily communities in Lansing, Grand Rapids and south-east Michigan. Addresses here are subscribers behind a fiber drop.

Notable

• Eyeball network, not hosting or transit. RIS sees 2 IPv4 prefixes carrying 16,384 addresses plus one IPv6 /32 (2604:71c0::/32), against 20 observed BGP neighbours. Twenty neighbours is a regional ISP that peers where it can and buys a couple of transits — not a carrier, which would show hundreds.
• The decisive evidence is reverse DNS: every sampled address across both 72.44.96.0/19 and 69.176.128.0/19 resolves to a generic <dashed-ip>.stellarbb.com name. Sequential, machine-generated PTRs spanning the whole allocation are what an access network puts on a subscriber pool; server and colo space gets individually named hosts instead.
• The rDNS also confirms the holder is first-party. The prefixes are announced by the same company whose domain appears in the PTRs, which rules out the address-broker shape entirely.

Interesting

• The SPARTAN-NET handle long outlived the brand — the company rebranded to STELLAR but kept the AS handle, a reminder that a registry handle is a historical artefact and never evidence of who runs the network today.