AS18

AS18 is a legacy single-digit allocation registered under ARIN to the University of Texas at Austin (RADB as-name UTNET), and it remains a live campus network. It announces the classic 128.62.0.0/16 and 128.83.0.0/16 blocks plus 129.116.0.0/16, 146.6.0.0/16, 198.213.192.0/18, 198.214.80.0/20, and 206.76.64.0/18 — about eight IPv4 prefixes (~299,520 addresses) — but originates no IPv6 as of June 2026. Its peers include the Texas Department of Information Resources (AS6922), Cogent (AS174), the University of Texas System (AS276), and AS1239, and it is present at one internet exchange (PIT MX in Querétaro, Mexico); the RADB policy imports from AS3354 (UT System) and AS145. ARIN RDAP records the allocation date as 1984-07-27, an early-Internet assignment. One hygiene note: RPKI coverage is thin — only one of the eight prefixes is RPKI-valid — and one prefix (198.214.250.0/23) shows an IRR parent-origin mismatch attributed to "Texas Educational and Sports Network, LLC," worth noting for route-validation triage and as a contrast to fully-signed AS17 (Purdue). For triage this is a live academic network carrying benign traffic; UT System (AS3354, AS276) and UT Dallas (AS20162) are distinct related entities. No notable public abuse signal was found as of June 2026.

Operator

University of Texas at Austin (ARIN OrgId UTAA; RADB as-name UTNET) [Confirmed] — ARIN RDAP / bgp.he.net

Country / RIR

US, ARIN [Confirmed]

Allocated

1984-07-27 (ARIN ASN RegDate; Updated 2003-07-09) [Confirmed] — ARIN RDAP

Org status

active — utexas.edu

Security/abuse context (NEUTRAL, DATED)

no notable public abuse signal found as of 2026-06-07; live academic network. IPinfo rank #32,057 global / #1,531 US (secondary, non-authoritative) — bgp.he.net

Network & routing

Network type

research / education [Confirmed]

Size

8 IPv4 prefixes (~299,520 addrs), 0 IPv6 originated; announces 128.62/16, 128.83/16, 129.116/16, 146.6/16, 198.213.192.0/18, 198.214.80.0/20, 206.76.64.0/18 — bgp.he.net (2026-06)

Routing/peering

peers AS6922 (Texas DIR), AS174 (Cogent), AS276 (UT System), AS1239; 1 IX (PIT MX, Querétaro); RADB imports from AS3354 (UT System) and AS145; RPKI thin — only 1 of 8 prefixes valid; 198.214.250.0/23 shows IRR parent-origin mismatch (Texas Educational and Sports Network, LLC) — bgp.he.net

Notable usage

UT-Austin campus AS; announces classic 128.62.0.0/16 and 128.83.0.0/16 — utexas.edu

Related ASNs

AS3354 and AS276 (University of Texas System); AS20162 (UT Dallas, distinct) [Confirmed]

Analyst note

Live academic network carrying benign traffic, but RPKI coverage is thin (only 1 of 8 prefixes valid) — worth noting for route-validation triage and as a contrast to fully-signed AS17 (Purdue).