AS572

AS572 is an ARIN-registered autonomous system held by Greater Baltimore Medical Center Inc, the corporate entity behind GBMC HealthCare's integrated system of care in Towson, Maryland — an acute hospital, GBMC Health Partners primary/specialty care, and Gilchrist hospice. Unlike a transit provider or research-and-education network, this is a straightforward enterprise/end-user ASN: a single organization registered it for its own multihomed connectivity rather than to serve downstream customers. ARIN RDAP's top-level autnum record puts the registration event at 2014-02-18, distinct from (and not to be confused with) two nested decoy dates in the same record — the registrant organization's own 2013-07-29 entity registration and the point-of-contact's 2014-04-11 entity registration, neither of which is the ASN's allocation date. Routing data shows a small, stable footprint: four IPv4 prefixes totaling 1,024 addresses, no IPv6 announcements, full IPv4 visibility across all 327 RIPE RIS peers, and a customer cone of just the ASN itself — consistent with a leaf network multihomed to three upstream providers with zero peers and zero downstream customers. CAIDA ranks it 35,261st globally. The organization's most notable public event is unrelated to the ASN's routing reputation: a December 2020 ransomware attack against GBMC's internal IT systems, reported by multiple outlets, which is a victimization incident rather than any abuse or hijack activity attributed to AS572's announced space. ARIN also flags the registered point-of-contact as unvalidated since September 2023.

Operator

Greater Baltimore Medical Center Inc (GBMC HealthCare — parent of Greater Baltimore Medical Center hospital, GBMC Health Partners, and Gilchrist hospice), Towson, MD [Confirmed] — https://rdap.arin.net/registry/autnum/572, https://www.gbmc.org/about-gbmc

Country / RIR

US, ARIN [Confirmed] — https://rdap.arin.net/registry/autnum/572

Allocated

2014-02-18 (ARIN autnum top-level registration event, 14:47:39 -04:00); last changed 2014-02-18 (identical — no changes since allocation) [Confirmed] — https://rdap.arin.net/registry/autnum/572, corroborated https://bgpview.io/asn/572

Org status

active per ARIN RDAP (status: active); GBMC HealthCare presents itself as a private, not-for-profit healthcare corporation (inferred from its GBMC Foundation/philanthropic framing; the fetched About page text does not use the literal word "non-profit")

[Likely] — https://rdap.arin.net/registry/autnum/572, https://www.gbmc.org/about-gbmc

Contacts

the abuse/NOC/technical/administrative POC is a named individual, Steve Hall (HALLS17-ARIN), whose personal mailbox and direct-dial number are not reproduced here — ARIN flags this POC as unvalidated since 2023-09-29 ("no response from the POC"); registrant address 6701 N. Charles St, Towson, MD 21204

[Confirmed] — https://rdap.arin.net/registry/autnum/572, https://stat.ripe.net/AS572

Security/abuse context (NEUTRAL)

no notable public abuse or threat-feed signal found for AS572 as of 2026-07-11 across general web search of Spamhaus/BGPStream-style terms and NANOG archives — an absence-of-evidence finding from search, not a direct Spamhaus/BGPStream API query. Distinct from the ASN's routing reputation: GBMC (the organization) was a ransomware attack VICTIM detected 2020-12-06, disrupting IT systems with no confirmed patient-data compromise — an incident against GBMC's own systems, not abuse originating from AS572's announced space [Confirmed for the incident; Unknown for current abuse posture] — https://www.securityweek.com/greater-baltimore-medical-center-hit-ransomware-attack/, https://databreaches.net/2020/12/07/md-ransomware-impacted-greater-baltimore-medical-centers-information-technology-systems/

Network & routing

Network type

enterprise/end-user network for a hospital healthcare system, not a transit provider, ISP, or R&E network; no published peering policy found on gbmc.org [Likely] — https://rdap.arin.net/registry/autnum/572, https://www.gbmc.org/about-gbmc

Size

4 IPv4 prefixes / 1024 IPv4 addresses (65.111.72.0/23, 198.185.27.0/24, 198.185.26.0/23, 198.185.26.0/24 — the /23 and its /24 sub-block both announced concurrently); 0 IPv6 prefixes; customer cone = 1 ASN (itself), 4 prefixes, 1024 addresses

[Confirmed] — https://stat.ripe.net/AS572, https://asrank.caida.org/asns/572

Routing/peering

fully visible on IPv4 (327/327 RIS peers), not announced on IPv6 (0/322); CAIDA asnDegree = 3 provider, 0 peer, 0 customer, matching 3 observed BGP neighbours in RIPEstat routing-status — a stub network multihomed to 3 upstreams with no peers or downstream customers; specific upstream ASN identities not present in the source data

[Confirmed] — https://asrank.caida.org/asns/572, https://stat.ripe.net/AS572

RPKI

not evaluated in this fetch — RIPEstat rpki-validation was skipped because it requires a specific prefix parameter, none was supplied [Unknown] — https://stat.ripe.net/RPKI

Notable usage

supports GBMC HealthCare's clinical/administrative IT — the site's own pages reference an Epic-based EHR, MyChart patient portal, Citrix remote access for physicians/employees, and imaging/dictation systems; no first-party "AS572 is used for X" statement exists, so this is inferred from the org's published service lines

[Likely] — https://www.gbmc.org/about-gbmc

Related ASNs

none identified in the sources consulted [Unknown]

Analyst note

A small, stable enterprise ASN for a Maryland hospital system. The top-level autnum registration date (2014-02-18) was correctly distinguished from two nested entity-level decoy dates (org registration 2013-07-29; POC registration 2014-04-11) in the same RDAP record.