AS10309 MARIN-MIDAS

MARIN-MIDAS is the network of the County of Marin, California, run under the banner of MIDAS — Marin Information and Data Access Systems, a shared-infrastructure consortium of county, city, school and non-profit agencies across the county.

What it's used for

MIDAS provides internet connectivity at public buildings, access to law-enforcement, emergency-response and justice systems, and inter-agency data sharing. The county's Information Services and Technology department operates it on behalf of the member agencies, so the AS carries a public-sector user population rather than a commercial one.

Notable

This is government, and the shape of the routing is the argument. RIS observes 12 IPv4 prefixes carrying 9,472 addresses and only 3 BGP neighbours. Almost all of the space is one contiguous run — 199.88.64.0/21, 199.88.72.0/22, 199.88.80.0/21, 199.88.88.0/22 and a string of longer prefixes up through 199.88.120.0/23 — i.e. a single legacy block being deaggregated for internal traffic engineering, plus one outlier (107.0.46.0/23). A network that announces one estate and buys from three neighbours is consuming connectivity for its own sites, not selling it.

The consortium model also explains the deaggregation: distinct member agencies sit in distinct sub-blocks and get advertised separately so each can be steered independently.

Interesting

The MIDAS name is worth flagging because the handle looks like a vendor brand and is not one. It is a shared government network, so addresses inside it can legitimately belong to a city, a school district or a non-profit partner rather than to the county itself — geolocating this space to "Marin County offices" is the obvious over-read to avoid.