AS11197 DART-HITCH

DART-HITCH belongs to Dartmouth-Hitchcock Medical Center, the academic medical centre in Lebanon, New Hampshire and the teaching hospital associated with Dartmouth's Geisel School of Medicine. Despite the Dartmouth name, this is the health system's network, not the college's.

What it's used for

Hospital and clinic infrastructure. The AS announces a single IPv4 prefix, the whole 130.189.0.0/16 — 65,536 addresses — registered to the medical centre's own ARIN block (DART-HITCH). No IPv6 is observed, and only two BGP neighbours: a pair of upstreams for redundancy, which is the standard multihomed-enterprise pattern and nothing like a carrier.

A /16 announced flat, with no deaggregation at all, is a strong signal of a single administrative domain rather than a provider carving space up for customers. It carries clinical systems, imaging, staff workstations, remote-access gateways and the public web presence for a health system spanning the main hospital and a network of clinics across New Hampshire and Vermont.

Notable

The address count makes this look like a mid-sized ISP on paper, but the two-neighbour peering estate and the single unbroken /16 say otherwise. This is the case the sweep keeps running into: address volume alone does not identify a role, and the neighbour count is the better discriminator.

No PTRs came back on the two addresses sampled. That is a sample of a /16 and supports no conclusion in either direction about how the reverse zone is delegated.