AS180

AS180 is one of the earliest Autonomous System Numbers ever allocated, registered with ARIN to the University of Michigan in Ann Arbor on 1988-04-28 under the handle UMICH-AS-4 (org handle UNIVER-118-Z). It is a legacy academic ASN that is now dormant: across BGP observatories it originates zero IPv4 and zero IPv6 prefixes and has not been visible in the global routing table since approximately March 2019. RIPE Stat reports 0 of 327 RIS peers observing it, and the CIDR Report describes it as not currently used to announce prefixes nor as a visible transit AS. The university's active internet routing now runs primarily under AS36375, with upstream transit via Merit Network (AS237); U-M also operates several sibling legacy ASNs (AS177 UMICH-AS-1, AS178 UMICH-AS-2, AS179 UMICH-AS-3). The only routing-table signal on record for AS180 is a single brief prefix announcement — 45.164.168.0/22, first seen 2019-02-12 and last seen 2019-03-06 — whose origin and legitimacy could not be independently verified; bgp.he.net flags an associated bogon, almost certainly a third-party data artifact or route leak rather than a legitimate U-M announcement. No notable public abuse signal was found as of 2026-06-18: AS180 is absent from the Spamhaus ASN-DROP list, appears in no threat feeds, and has no NANOG or community incident history, consistent with its dormant status. Because it announces no prefixes, RPKI posture is not meaningfully assessable (0 valid / 0 invalid). The ARIN registration date is a registry fact, not an IEEE-published date.

Operator

University of Michigan (ARIN OrgId UNIVER-118-Z; IT Communications Services, 4251 Plymouth Road, Suite 2-2200, Ann Arbor, MI 48105-3640) [Confirmed] — ARIN RDAP

AS name / handle

UMICH-AS-4 (autnum handle AS180) [Confirmed] — rdap.arin.net/registry/autnum/180

Country / RIR

US, ARIN [Confirmed]

Allocated

ARIN ASN registration 1988-04-28 (registry date — among the earliest ASNs ever allocated; NOT an IEEE-published date); autnum last changed 2020-01-14 [Confirmed]

Security/abuse context (NEUTRAL, DATED)

no notable public abuse signal found as of 2026-06-18; absent from Spamhaus ASN-DROP (list dated 2026-05-29), no threat-feed hits, no NANOG mentions; institution-level U-M cyber incidents (2023 network shutdown; May 2026 Canvas breach) are unrelated to AS180 routing

Abuse contact

report-abuse@umich.edu (IT Abuse Investigation, ARIN IAI8-ARIN, +1-734-764-4357); technical: UMnet Administration (UA11-ORG-ARIN, +1-734-647-4200)

Network & routing

Network type

academic / educational institution network, operated by U-M Information and Technology Services (ITS); legacy/dormant [Confirmed] — bgp.tools, RDAP

Routing status

dormant — not visible in the global routing table since ~March 2019; originates 0 IPv4 and 0 IPv6 prefixes; RIPE Stat 0/327 RIS peers; CIDR Report confirms no announced prefixes and no visible transit [Confirmed] — bgp.he.net / bgp.tools / stat.ripe.net / cidr-report.org

Peering

no current upstreams or peers in the routing table; one historical IPv4 peer (AS28427, Mobile Cashier Systems SA de CV, Mexico) recorded by bgp.he.net is a stale artifact; no PeeringDB entry (peeringdb.com/asn/180 → 404) [Likely] — bgp.he.net / bgp.tools

RPKI

not meaningfully assessable for a non-announcing ASN — bgp.he.net reports 0 valid / 0 invalid ROAs [Likely] — bgp.he.net

AS rank / customer cone

Unknown — not reported by bgp.he.net or bgp.tools for this dormant ASN

Notable usage

legacy early-internet ASN (allocated 1988) assigned to University of Michigan; active U-M routing now runs under AS36375 with upstream via Merit Network (AS237); AS180 itself is retired from active routing [Likely] — its.umich.edu / ipinfo.io/AS36375

Related ASNs

AS177 (UMICH-AS-1), AS178 (UMICH-AS-2), AS179 (UMICH-AS-3), AS36375 (primary active U-M ASN) [Confirmed] — bgp.tools, networksdb.io

2019 anomaly

a single prefix 45.164.168.0/22 first seen 2019-02-12, last seen 2019-03-06; origin/legitimacy unverified; bgp.he.net flags an associated bogon — treat as a third-party data artifact, not a legitimate U-M announcement [Likely] — stat.ripe.net / bgp.he.net

AS-SET

as180:as-cone (RADB, 1 member) [Likely] — bgp.tools

Analyst note

clean, dormant legacy academic ASN; live routing carried under AS36375, not AS180. The sole 2019 prefix and bogon flag are best read as noise/artifacts.