AS11131 UMBC-AS

UMBC-AS is the campus autonomous system of the University of Maryland, Baltimore County, the public research university at 1000 Hilltop Circle, Baltimore. It announces the university's own address space and nothing resembling a provider's inventory.

What it's used for

A large research-university campus network. RIS observes just 3 IPv4 prefixes but 82,176 addresses — an unusually high address-per-prefix ratio, explained entirely by the first entry: 130.85.0.0/16, a full class-B-sized block of 65,536 addresses registered to UMBCNET. The other two are 136.160.0.0/18 (16,384 addresses) and 199.201.245.0/24, plus one IPv6 prefix, 2620:0:5300::/44.

This is the profile of an institution that was allocated generous space early and still announces it as a clean aggregate: three routes, no deaggregation, three observed BGP neighbours. Campus traffic — teaching, administration, research computing, residence halls — flows over a handful of upstreams, most likely including the regional research-and-education network alongside commodity transit.

Notable

The registrant of the /18 is not UMBC but COMBNET, whose ARIN organisation is the University System of Maryland — the statewide system UMBC belongs to, registered at System Administration, Adelphi, MD. A prefix registered to a different legal entity than the announcing AS can be an IP-leasing tell; here it is the mundane opposite. The parent university system holds space and a constituent campus announces a slice of it. The remaining blocks (UMBCNET, UMBC-EXT-NET) are UMBC's own direct allocations.

Interesting

The sampled reverse DNS shows the campus core exactly where you would expect it — engcr-apic2-cimc.net.umbc.edu is an out-of-band management interface on a data-centre switch fabric, sitting in the .net.umbc.edu infrastructure zone. One sampled address in the external /24 answers under an unrelated domain, netmasters.com, which is a useful reminder that reverse DNS describes what a piece of space carries, never who holds it.