AS11534 PHILA-SCHOOL-DISTRICT

PHILA-SCHOOL-DISTRICT is the network of the School District of Philadelphia, the eighth-largest public school district in the United States and the largest in Pennsylvania. RIS sees a single IPv4 prefix, 170.235.0.0/16 — about 65,536 addresses — no IPv6, and 3 observed BGP neighbours.

What it's used for

School and administrative connectivity for the district: classroom and lab networks across its schools, the central administration, and the public-facing services that sit in front of them. The single /16 is the whole announced inventory, and reverse DNS on it resolves under philasd.org — the district's own domain, with extranet.philasd.org on an address in the block. That is first-party rDNS on first-party space, so the routing and the naming agree with the holder rather than pointing at some upstream or a third party.

Notable

The /16 is registered not to the school district but to the City of Philadelphia (CITY-OF-PHILLY). That is not a third-party registrant of the sort that signals leased or brokered address space; it is municipal reality. The district is a public body of the city, and the city holds the number resources for its agencies. A block registered to the city and announced by the schools is exactly what a shared municipal allocation looks like.

Three neighbours against 65k addresses is an end-site with a couple of upstreams — a large institution buying transit, not a carrier.