AS705

AS705 is a dormant, unrouted autonomous system number inside ARIN's legacy UUNET block (AS701-AS705), registered to Verizon Business via MCI Communications Services LLC. It announces zero IPv4 and zero IPv6 prefixes today and does not appear in the global routing table, making it an inactive placeholder within an otherwise live Tier-1 backbone block.

ARIN does not maintain a separate RDAP object for AS705 alone; querying autnum 705 returns the combined AS701-AS705 range, RIR object name UUNET, registrant handle MCICS. That block's top-level registration event dates to 1990-08-03, with a last-changed event on 2022-05-31 — both are first-party ARIN RDAP facts, not IEEE or third-party scrape artifacts.

The block traces to UUNET, one of the first commercial U.S. ISPs (founded 1987) and an original Tier-1 backbone operator. UUNET's assets passed through MFS/WorldCom (1996) and MCI, then to Verizon after its 2006 MCI acquisition, forming Verizon Business. Within the block, AS701 (US), AS702 (Europe), and AS703 (ASPAC) are the actively peered, PeeringDB-listed regional networks; AS705 shows no such presence and appears to be an unused number reserved inside the range rather than a distinct advertised network.

The one notable historical event tied to this pair is the August 12, 2014 route leak: AS701 and AS705 leaked roughly 22,000 more-specific /24 prefixes, helping push the global IPv4 routing table past the 512k-route ceiling and crashing older Cisco 6500 hardware, with Shaw Canada reporting nationwide routing failures. RFC 7908 cites the incident as a Type 4 accidental-deaggregation route leak, and NANOG archives characterize it as transient and unintentional rather than malicious.

Operator

Verizon Business, operated via MCI Communications Services LLC (formerly MCI Communications Services, Inc.; ARIN registrant handle MCICS), an indirect wholly-owned subsidiary of Verizon Communications Inc. [Confirmed] — ARIN RDAP autnum 705, Verizon tariff filing

Country / RIR

US, ARIN — no separate AS705 RDAP object exists; queries return the combined AS701-AS705 block [Confirmed] — https://rdap.arin.net/registry/autnum/705

Allocated

1990-08-03 (ARIN RDAP top-level registration event for the AS701-705 block, NOT an IEEE date); last changed 2022-05-31 [Confirmed, corroborated independently by two angles + bgp.tools "registered since August 3, 1990"] — https://rdap.arin.net/registry/autnum/705, https://bgp.tools/as/705

Org status

active — Verizon Communications Inc. (NYSE: VZ) subsidiary; ARIN block status "active" [Confirmed] — https://rdap.arin.net/registry/autnum/705

Contacts

abuse-mail@verizonbusiness.com, abuse@verizon.com, IPMGMT@verizon.com; +1-800-900-0241; registrant address 22001 Loudoun County Pkwy, Ashburn, VA 20147 [Confirmed] — ARIN RDAP entity records (SWIPP9-ARIN, ABUSE5603-ARIN, VIS1-ARIN)

Security/abuse context (NEUTRAL, DATED)

no notable public abuse signal found as of 2026-07-24 (NANOG archives, general abuse/threat-feed search)

Network & routing

Network type

legacy UUNET global IP backbone, now Verizon Business's global IP network; AS705 shows no independent PeeringDB or BGP-visible presence (regional siblings AS701/AS702/AS703 are the actively peered networks)

[Likely] — https://www.verizon.com/business/terms/peering/, https://www.peeringdb.com/asn/701, https://www.peeringdb.com/asn/702

Size

dormant — 0 IPv4 and 0 IPv6 announced prefixes, not present in the global routing table [Confirmed] — https://bgp.tools/as/705

Routing/peering

no upstreams, no peers, no customer cone observed. CAIDA ASRank has no measured ranking for AS705: its record returns seen=false and cliqueMember=false, an AS-degree of 0 total / 0 customer / 0 peer / 0 provider, and a cone of 1 ASN / 0 prefixes / 0 addresses. The rank value it carries, 79459, is the shared bottom-rank sentinel CAIDA assigns to every ASN it has never observed in the topology graph — not a position — so as_rank is recorded null here rather than 79459

[Confirmed] — https://bgp.tools/as/705, https://api.asrank.caida.org/v2/restful/asns/705 (queried 2026-07-28)

RPKI

not assessable — no announced prefixes, therefore no ROAs to validate [Confirmed] — https://bgp.tools/as/705

Notable usage / incident

UUNET → MFS/WorldCom → MCI → Verizon lineage; AS701/AS705 leaked ~22,000 more-specific /24 prefixes on 2014-08-12, contributing to the global routing table's first breach of the 512k-route limit (RFC 7908 Type 4 route leak) [Confirmed] — https://www.rfc-editor.org/rfc/rfc7908.html, https://www.kentik.com/blog/a-brief-history-of-the-internets-biggest-bgp-incidents/

Related ASNs

AS701 (Verizon Business-US), AS702 (Verizon Business-Europe), AS703 (Verizon Business-ASPAC), AS704 [Confirmed for block membership; Likely for AS704 specifics — not independently checked] — https://www.peeringdb.com/asn/701, https://www.peeringdb.com/asn/702, https://bgpview.io/asn/703

Analyst note

one research angle (A1) returned content entirely unrelated to AS705 (an unrelated multi-turn conversation transcript with research instructions appended at the end); another angle (A3) independently flagged the same appended-instruction mismatch in chat before proceeding. A1's content was excluded from synthesis — none of it was used as a source. All ASN facts in this entry derive from angles A2-A5.