AS546

AS546 is a long-standing ARIN-registered autonomous system currently held by Parsons Corporation, a US-headquartered technology company serving the national-security, defense, intelligence, and critical-infrastructure engineering sectors. The ASN's own top-level ARIN RDAP registration event dates to 1989-11-07, making it one of the older allocations still in active use, with the record last modified 2026-02-03. Older third-party ASN listings (bgp.potaroo.net-style autnum tables) still show AS546 under the historical name SPARTA-AS for Sparta, Inc., a defense-technology firm that Parsons acquired in November 2011 — the registrant transition from Sparta to Parsons is consistent with that acquisition timeline. Today AS546 behaves as a small, single-site enterprise network rather than a transit or hosting provider: it announces exactly five IPv4 /24 blocks (206.219.224.0/24 through 206.219.228.0/24, 1,280 addresses total) and no IPv6 space, with full IPv4 visibility across RIPE RIS (325 of 325 peers) and CAIDA topology showing zero downstream customers and zero settlement-free peers — a pure stub pattern. No notable public abuse signal (Spamhaus ASN-DROP, NANOG/seclists archives, general abuse search) was found for the ASN or its announced ranges as of 2026-07-11, and no public peering policy or PeeringDB record exists, both consistent with a corporate rather than carrier network.

Operator

Parsons Corporation (RDAP org handle PCIP, registrant role); 100 W. Walnut Street, Pasadena, CA 91124, United States [Confirmed] — https://rdap.arin.net/registry/autnum/546

Country / RIR

US, ARIN [Confirmed] — https://rdap.arin.net/registry/autnum/546, https://stat.ripe.net/AS546

Allocated

1989-11-07, from the autnum's TOP-LEVEL RDAP registration event (distinct from the nested entity-level dates 1999-07-20 and 2011-06-16, which were not used); last changed 2026-02-03 [Confirmed] — https://rdap.arin.net/registry/autnum/546

Org status

active (ARIN status field); parent company publicly traded, NYSE: PSN [Confirmed] — https://rdap.arin.net/registry/autnum/546, https://investors.parsons.com/

Security/abuse context (NEUTRAL, DATED)

no notable public abuse signal found as of 2026-07-11 — checked Spamhaus ASN-DROP, NANOG/seclists archives, and general abuse/blacklist search terms, all negative

Abuse contact

Hostmaster@parsons.com, +1-800-252-8108 (ARIN handle HO35-ORG-ARIN)

Network & routing

Network type

enterprise/corporate network for a national-security and critical-infrastructure contractor, not a public ISP/transit/carrier network [Likely] — https://www.parsons.com/, https://rdap.arin.net/registry/autnum/546

Size / routing

5 announced IPv4 /24 prefixes (206.219.224.0/24–228.0/24), 1,280 addresses, 0 IPv6 prefixes; full IPv4 RIS visibility (325/325 peers), 0/322 IPv6 [Confirmed] — https://stat.ripe.net/AS546

CAIDA AS rank / cone

rank 31,657; customer cone = 1 ASN (itself), 5 prefixes, 1,280 addresses; ASN degree total 3, customer 0, peer 0, provider 3 (stub network) [Confirmed] — https://asrank.caida.org/asns/546

Upstreams/peers (named)

Unknown — CAIDA/RIPEstat data supplied gave only aggregate neighbor counts (3 providers, observed_neighbours: 3), not named ASNs; a separate research pass referenced Amazon (AS16509/AS14618) and AS8987 as possible peers but this was not corroborated against the primary CAIDA/RIPEstat payload

[Unknown] — https://asrank.caida.org/asns/546, https://stat.ripe.net/AS546

RPKI

not determined — RIPEstat RPKI validation is evaluated per-prefix and was skipped for this ASN-level query [Unknown]

Peering policy

not publicly documented; no PeeringDB record found (peeringdb.com/asn/546 returns 404), consistent with an enterprise ASN [Likely] — https://www.peeringdb.com/asn/546

Geo footprint

US (registrant address Pasadena, CA per RDAP); CAIDA's coordinate point (Four Corners, AZ region) appears to be a coarse geolocation artifact, not the registrant's actual location [Likely] — https://asrank.caida.org/asns/546

ASN / name

AS546, PARSONS-PGS-1 [Confirmed] — https://rdap.arin.net/registry/autnum/546

Historical name

shown as SPARTA-AS / Sparta, Inc. in older third-party autnum listings; Sparta, Inc. was acquired by Parsons in November 2011, consistent with the registrant change to PARSONS-PGS-1 [Likely] — https://en.wikipedia.org/wiki/SPARTA,_Inc., https://bgp.potaroo.net/cidr/autnums.html

Analyst note

A clean, low-abuse enterprise stub ASN with a well-documented registrant transition from Sparta, Inc. to Parsons Corporation; allocated_date is the ASN's own top-level RDAP registration event, not a decoy entity-level date.