158.16.0.0/16

Currently announced by AS1540 Headquarters, USAISC, in the routed prefix 158.16.0.0/16.

Current ASN: AS1540; Headquarters, USAISC
Routed prefix: 158.16.0.0/16; Most specific route covering this prefix
ASNs over time: 1; 1 announcement record
RIR allocation: ARIN; United States · 158.16.0.0/16

Routing data · Nov 8, 2026, 10:26 UTC

ASN historyEvery routed prefix covering 158.16.0.0/16

Prefix	ASN	Name	Registered country	First seen (UTC)	Last seen (UTC)	Status
158.16.0.0/16	AS1540	Headquarters, USAISC	United States	Before monitoring	2026-11-08 10:26	Announcing

More specific routes19 total

Prefix	ASN	Name	Registered country	First seen (UTC)	Last seen (UTC)	Status
158.16.0.0/20	AS1540	Headquarters, USAISC	United States	Before monitoring	2026-11-08 10:26	Announcing
158.16.16.0/24	AS1540	Headquarters, USAISC	United States	Before monitoring	2026-11-08 10:26	Announcing
158.16.24.0/21	AS1540	Headquarters, USAISC	United States	Before monitoring	2026-11-08 10:26	Announcing
158.16.32.0/23	AS1540	Headquarters, USAISC	United States	2026-11-05 02:20	2026-11-08 10:26	Announcing
158.16.34.0/23	AS1540	Headquarters, USAISC	United States	2026-11-05 02:20	2026-11-08 10:26	Announcing
158.16.36.0/23	AS1540	Headquarters, USAISC	United States	2026-11-05 02:20	2026-11-08 10:26	Announcing
158.16.38.0/24	AS1540	Headquarters, USAISC	United States	2026-11-05 02:20	2026-11-08 10:26	Announcing
158.16.48.0/23	AS1540	Headquarters, USAISC	United States	Before monitoring	2026-11-08 10:26	Announcing
158.16.224.0/23	AS1540	Headquarters, USAISC	United States	Before monitoring	2026-11-08 10:26	Announcing
158.16.226.0/23	AS1540	Headquarters, USAISC	United States	Before monitoring	2026-11-08 10:26	Announcing
158.16.228.0/23	AS1540	Headquarters, USAISC	United States	Before monitoring	2026-11-08 10:26	Announcing
158.16.230.0/23	AS1540	Headquarters, USAISC	United States	Before monitoring	2026-11-08 10:26	Announcing
158.16.232.0/23	AS1540	Headquarters, USAISC	United States	Before monitoring	2026-11-08 10:26	Announcing
158.16.234.0/23	AS1540	Headquarters, USAISC	United States	Before monitoring	2026-11-08 10:26	Announcing
158.16.237.0/24	AS1540	Headquarters, USAISC	United States	Before monitoring	2026-11-08 10:26	Announcing
158.16.239.0/24	AS1540	Headquarters, USAISC	United States	Before monitoring	2026-11-08 10:26	Announcing
158.16.242.0/23	AS1540	Headquarters, USAISC	United States	Before monitoring	2026-11-08 10:26	Announcing
158.16.244.0/23	AS1540	Headquarters, USAISC	United States	Before monitoring	2026-11-08 10:26	Announcing
158.16.246.0/23	AS1540	Headquarters, USAISC	United States	Before monitoring	2026-11-08 10:26	Announcing

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: 158.16.0.0/16
Country: United States
Allocation date: 1992-12-30
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.