155.220.0.0/16

Currently announced by AS5972 United States Department of Defense (DoD), in the routed prefix 155.220.0.0/16.

Current ASN: AS5972; United States Department of Defense (DoD)
Routed prefix: 155.220.0.0/16; Most specific route covering this prefix
ASNs over time: 1; 1 announcement record
RIR allocation: ARIN; United States · 155.220.0.0/16

Routing data · Nov 8, 2026, 10:26 UTC

ASN historyEvery routed prefix covering 155.220.0.0/16

Prefix	ASN	Name	Registered country	First seen (UTC)	Last seen (UTC)	Status
155.220.0.0/16	AS5972	United States Department of Defense (DoD)	United States	Before monitoring	2026-11-08 10:26	Announcing

More specific routes14 total

Prefix	ASN	Name	Registered country	First seen (UTC)	Last seen (UTC)	Status
155.220.6.0/23	AS5972	United States Department of Defense (DoD)	United States	Before monitoring	2026-11-08 10:26	Announcing
155.220.8.0/21	AS5972	United States Department of Defense (DoD)	United States	Before monitoring	2026-11-08 10:26	Announcing
155.220.18.0/23	AS5972	United States Department of Defense (DoD)	United States	Before monitoring	2026-11-08 10:26	Announcing
155.220.24.0/23	AS5972	United States Department of Defense (DoD)	United States	Before monitoring	2026-11-08 10:26	Announcing
155.220.26.0/24	AS5972	United States Department of Defense (DoD)	United States	Before monitoring	2026-11-08 10:26	Announcing
155.220.35.0/24	AS5972	United States Department of Defense (DoD)	United States	Before monitoring	2026-11-08 10:26	Announcing
155.220.36.0/24	AS5972	United States Department of Defense (DoD)	United States	Before monitoring	2026-11-08 10:26	Announcing
155.220.40.0/24	AS5972	United States Department of Defense (DoD)	United States	Before monitoring	2026-11-08 10:26	Announcing
155.220.56.0/22	AS5972	United States Department of Defense (DoD)	United States	Before monitoring	2026-11-08 10:26	Announcing
155.220.132.0/23	AS5972	United States Department of Defense (DoD)	United States	Before monitoring	2026-11-08 10:26	Announcing
155.220.173.0/24	AS5972	United States Department of Defense (DoD)	United States	Before monitoring	2026-11-08 10:26	Announcing
155.220.180.0/23	AS5972	United States Department of Defense (DoD)	United States	Before monitoring	2026-11-08 10:26	Announcing
155.220.38.0/23	AS5972	United States Department of Defense (DoD)	United States	Before monitoring	2026-11-03 20:23	Stopped
155.220.252.0/24	AS5972	United States Department of Defense (DoD)	United States	Before monitoring	2026-11-04 20:26	Stopped

Change logAll changes

The routes covering this address have had no origin changes since ASNBase started monitoring.

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RIR allocation record

Registry: ARIN
Allocated block: 155.220.0.0/16
Country: United States
Allocation date: 1992-02-01
Status: allocated

From the RIRs’ delegated statistics files. Shows where the addresses are registered, not where they are used.

How monitoring works

Every 2 hours ASNBase takes the bgp.tools global routing table (prefix → origin ASN) and compares it with the previous one. The detected time is the time of that comparison; the actual change can be up to about 2 hours earlier.
Only routes seen by more than 100 bgp.tools peers are listed as changes; routes with less visibility are only kept in the history.
A new announcement counts only if it is still in the next routing table, and a withdrawal only if the prefix is missing from two tables in a row, so short flaps are ignored.
ASNBase has been monitoring since 2026-10-19. “Before monitoring” under “First seen” means the route was already announced when monitoring started; the earlier date is unknown.
Prefixes first seen during the first day of monitoring do not count as new announcements: most of them were simply missing from the table at the moment monitoring started.
Countries and regions follow the ASN’s registration, not the actual location of the IP addresses.