AS636

AS636 is a legacy autonomous system number registered under ARIN as part of DNIC-ASBLK-00616-00665, a block of fifty ASNs (AS616 through AS665) assigned as a group to the United States Department of Defense rather than delegated individually — a common pattern for older DoD Network Information Center (DNIC) allocations. The registrant organization is the U.S. Department of Defense, with day-to-day registration and abuse contacts handled by DISA-Columbus (Defense Information Systems Agency) at 300 North James Road, Whitehall, OH. ARIN's RDAP autnum record carries a top-level registration event dated 1990-04-19, independently corroborated by bgp.tools, bgp.he.net, ip2location, and iplocate.io, with the record last changed 2025-09-12. Live routing shows AS636 announcing five IPv4 prefixes (roughly 6,656 addresses, from 214.58.192.0/20 down to 214.58.222.0/24) and no IPv6 space, with a single observed BGP relationship to AS367, another DoD-registered ASN — consistent with the closed, DoD-internal peering typical of this block rather than open commercial peering. No public peering-policy page, PeeringDB listing under AS636 specifically, or dedicated operator-facing website describing the ASN was found. No Spamhaus ASN-DROP listing, NANOG abuse-thread mentions, or documented BGP hijack incident tied to AS636 turned up in research, though the negative hijack finding reflects search-visibility limits rather than an exhaustive registry check.

Operator

United States Department of Defense (DoD); registrant org handle within the DNIC block, day-to-day administration by DISA-Columbus [Confirmed] — https://rdap.arin.net/registry/autnum/636

Country / RIR

US, ARIN [Confirmed] — https://rdap.arin.net/registry/autnum/636

Allocated

1990-04-19 — ARIN RDAP autnum TOP-LEVEL registration event for DNIC-ASBLK-00616-00665 (the 50-ASN block AS636 belongs to; the block has no separately-dated individual AS636 sub-record). Corroborated independently by three additional sources. This is a block-level registration date applying to the whole 616–665 range, not an AS636-specific delegation event, but per RIR-first-party-fact policy it is recorded, not nulled [Confirmed] — https://rdap.arin.net/registry/autnum/636, https://bgp.tools/as/636, https://www.iplocate.io/AS636, https://www.ip2location.com/as636

Org status

active (ARIN RDAP autnum status "active"; DNIC org contact status "validated") [Confirmed] — https://rdap.arin.net/registry/autnum/636

Website

Unknown — no dedicated operator-facing page for AS636 or the DNIC block found; disa.mil homepage returned only a generic portal shell with no AS636-specific content [Unknown] — https://www.disa.mil

Contacts

disa.columbus.ns.mbx.hostmaster-dod-nic@mail.mil (abuse/hostmaster); DISA-Columbus, 300 North James Road, Whitehall, OH 43213 [Confirmed] — https://rdap.arin.net/registry/autnum/636

Security/abuse context (NEUTRAL, DATED)

not present on the Spamhaus ASN-DROP list (checked both the retired .txt and current .json feeds, 419 records) as of 2026-07-17; no NANOG archive threads naming AS636 in connection with abuse; no documented BGP hijack incident found, though this reflects search-visibility limits rather than an exhaustive hijack-database check [Confirmed for Spamhaus; Likely for NANOG/hijack absence] — https://www.spamhaus.org/drop/asndrop.json, https://mailman.nanog.org/pipermail/nanog/

Network & routing

Network type

US federal government (DoD) network; third-party BGP classification is "Stub AS" (single-homed, non-transit), no IPv6 announced [Likely] — https://bgp.he.net/AS636, https://ipinfo.io/AS636

Size

5 IPv4 prefixes announced (214.58.192.0/20, 214.58.208.0/22, 214.58.218.0/24, 214.58.222.0/24, 214.58.232.0/22), ~6,656 addresses; 0 IPv6 prefixes [Confirmed] — https://bgp.he.net/AS636

Routing/peering

sole observed BGP relationship is AS367 (also DoD-registered), acting as both upstream and peer in different toolsets; no PeeringDB entry found under AS636 within the DoD org (id 17705) [Likely] — https://bgp.tools/as/636, https://bgp.he.net/AS636, https://www.peeringdb.com/org/17705

Peering policy

not published; no dedicated peering-policy page or PeeringDB listing for AS636; presumed closed/DoD-internal given the sole DoD peer [Unknown/Likely] — https://www.peeringdb.com/org/17705

RPKI

0 valid / 0 invalid ROAs observed for announced prefixes; no RPKI coverage detected [Likely] — https://bgp.he.net/AS636

Notable usage

member of the legacy group-assigned block DNIC-ASBLK-00616-00665 (AS616–AS665), a historical/legacy-style ASN block rather than an individually delegated modern ASN [Confirmed] — https://rdap.arin.net/registry/autnum/636, https://ipinfo.io/AS636

ASN

AS636 [Confirmed] — https://rdap.arin.net/registry/autnum/636

Last changed

2025-09-12 [Confirmed] — https://rdap.arin.net/registry/autnum/636

Analyst note

legacy DoD block-assignment ASN (one of fifty in DNIC-ASBLK-00616-00665); allocation date is block-level, not AS636-specific, but is a genuine first-party RIR fact and is recorded per policy rather than nulled.