166.218.0.0/16

Currently announced by AS20057 AT&T Enterprises, LLC, in the routed prefix 166.218.0.0/16.

Current ASN: AS20057; AT&T Enterprises, LLC
Routed prefix: 166.218.0.0/16; Most specific route covering this prefix
ASNs over time: 2; 3 announcement records
RIR allocation: ARIN; United States · 166.216.0.0/14

Routing data · Nov 8, 2026, 10:26 UTC

ASN historyEvery routed prefix covering 166.218.0.0/16

Prefix	ASN	Name	Registered country	First seen (UTC)	Last seen (UTC)	Status
166.218.0.0/16	AS20057	AT&T Enterprises, LLC	United States	Before monitoring	2026-11-08 10:26	Announcing
166.218.0.0/15	AS20057	AT&T Enterprises, LLC	United States	Before monitoring	2026-11-08 10:26	Announcing
166.216.0.0/14	AS7018	AT&T US - 7018	United States	Before monitoring	2026-11-08 10:26	Announcing

More specific routes17 total

Prefix	ASN	Name	Registered country	First seen (UTC)	Last seen (UTC)	Status
166.218.0.0/17	AS20057	AT&T Enterprises, LLC	United States	Before monitoring	2026-11-08 10:26	Announcing
166.218.24.0/23	AS20057	AT&T Enterprises, LLC	United States	Before monitoring	2026-11-08 10:26	Announcing
166.218.48.0/21	AS20057	AT&T Enterprises, LLC	United States	Before monitoring	2026-11-08 10:26	Announcing
166.218.128.0/17	AS20057	AT&T Enterprises, LLC	United States	Before monitoring	2026-11-08 10:26	Announcing
166.218.236.0/24	AS20057	AT&T Enterprises, LLC	United States	Before monitoring	2026-11-08 10:26	Announcing
166.218.237.0/24	AS20057	AT&T Enterprises, LLC	United States	Before monitoring	2026-11-08 10:26	Announcing
166.218.238.0/24	AS20057	AT&T Enterprises, LLC	United States	Before monitoring	2026-11-08 10:26	Announcing
166.218.239.0/24	AS20057	AT&T Enterprises, LLC	United States	Before monitoring	2026-11-08 10:26	Announcing
166.218.240.0/24	AS20057	AT&T Enterprises, LLC	United States	Before monitoring	2026-11-08 10:26	Announcing
166.218.241.0/24	AS20057	AT&T Enterprises, LLC	United States	Before monitoring	2026-11-08 10:26	Announcing
166.218.242.0/24	AS20057	AT&T Enterprises, LLC	United States	Before monitoring	2026-11-08 10:26	Announcing
166.218.243.0/24	AS20057	AT&T Enterprises, LLC	United States	Before monitoring	2026-11-08 10:26	Announcing
166.218.246.0/23	AS20057	AT&T Enterprises, LLC	United States	Before monitoring	2026-11-08 10:26	Announcing
166.218.248.0/23	AS20057	AT&T Enterprises, LLC	United States	Before monitoring	2026-11-08 10:26	Announcing
166.218.250.0/23	AS20057	AT&T Enterprises, LLC	United States	Before monitoring	2026-11-08 10:26	Announcing
166.218.252.0/24	AS20057	AT&T Enterprises, LLC	United States	Before monitoring	2026-11-08 10:26	Announcing
166.218.253.0/24	AS20057	AT&T Enterprises, LLC	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: 166.216.0.0/14
Country: United States
Allocation date: 2025-04-01
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.