221.144.0.0/12

Currently announced by AS4766 KT Corporation (Korea Telecom), in the routed prefix 221.144.0.0/12.

Current ASN: AS4766; KT Corporation (Korea Telecom)
Routed prefix: 221.144.0.0/12; Most specific route covering this prefix
ASNs over time: 1; 1 announcement record
RIR allocation: APNIC; South Korea · 221.144.0.0/12

Routing data · Nov 8, 2026, 12:23 UTC

ASN historyEvery routed prefix covering 221.144.0.0/12

Prefix	ASN	Name	Registered country	First seen (UTC)	Last seen (UTC)	Status
221.144.0.0/12	AS4766	KT Corporation (Korea Telecom)	South Korea	Before monitoring	2026-11-08 12:23	Announcing

More specific routes51 total

Prefix	ASN	Name	Registered country	First seen (UTC)	Last seen (UTC)	Status
221.144.0.0/13	AS4766	KT Corporation (Korea Telecom)	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.144.37.0/24	AS4766	KT Corporation (Korea Telecom)	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.144.152.0/24	AS55622	CNUE	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.144.191.0/24	AS152198	Gangwon State University	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.145.178.0/24	AS45400	Korea Telecom	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.145.224.0/24	AS4766	KT Corporation (Korea Telecom)	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.146.17.0/24	AS4766	KT Corporation (Korea Telecom)	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.146.193.0/24	AS9856	WOORI Investment @ Securities	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.146.229.0/24	AS9972	INTMANAGEMENT Corp.,	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.147.50.0/24	AS152214	Korean Air Lines	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.147.51.0/24	AS4766	KT Corporation (Korea Telecom)	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.147.52.0/24	AS4766	KT Corporation (Korea Telecom)	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.147.53.0/24	AS4766	KT Corporation (Korea Telecom)	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.147.54.0/24	AS4766	KT Corporation (Korea Telecom)	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.147.55.0/24	AS4766	KT Corporation (Korea Telecom)	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.147.83.0/24	AS9526	KOSCOM	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.147.101.0/24	AS9850	WOW-TV	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.149.141.0/24	AS10185	Hana Bank Co.	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.149.230.0/24	AS45360	SSANGYONG CEMENT INDUSTRY CO.,LTD	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.149.240.0/22	AS131842	Office of the president	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.150.21.0/24	AS10184	Korean Federation of Community Credit Cooperatives	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.150.114.0/24	AS55592	Korea Data Telecommunication Co., Ltd.	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.150.156.0/23	AS4766	KT Corporation (Korea Telecom)	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.150.196.0/24	AS38697	Hankyong National Univercity	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.151.165.0/24	AS38405	Gwang Myeong Office of Education	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.151.172.0/24	AS38112	Korea Housing Urban Guarantee Corporation	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.151.180.0/24	AS9526	KOSCOM	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.152.0.0/13	AS4766	KT Corporation (Korea Telecom)	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.153.249.0/24	AS4766	KT Corporation (Korea Telecom)	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.154.82.0/24	AS4766	KT Corporation (Korea Telecom)	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.154.83.0/24	AS4766	KT Corporation (Korea Telecom)	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.154.84.0/24	AS4766	KT Corporation (Korea Telecom)	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.154.85.0/24	AS4766	KT Corporation (Korea Telecom)	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.154.86.0/24	AS4766	KT Corporation (Korea Telecom)	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.154.87.0/24	AS4766	KT Corporation (Korea Telecom)	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.154.88.0/24	AS4766	KT Corporation (Korea Telecom)	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.154.89.0/24	AS4766	KT Corporation (Korea Telecom)	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.154.90.0/24	AS4766	KT Corporation (Korea Telecom)	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.157.100.0/22	AS4766	KT Corporation (Korea Telecom)	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.157.104.0/21	AS4766	KT Corporation (Korea Telecom)	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.157.112.0/22	AS4766	KT Corporation (Korea Telecom)	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.157.116.0/24	AS4766	KT Corporation (Korea Telecom)	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.157.125.0/24	AS152232	kt cloud Co., Ltd	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.157.126.0/24	AS4766	KT Corporation (Korea Telecom)	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.157.127.0/24	AS4766	KT Corporation (Korea Telecom)	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.157.128.0/23	AS4766	KT Corporation (Korea Telecom)	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.158.73.0/24	AS17576	National Research Foundation of Korea	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.159.130.0/24	AS4766	KT Corporation (Korea Telecom)	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.159.186.0/24	AS4766	KT Corporation (Korea Telecom)	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.159.187.0/24	AS4766	KT Corporation (Korea Telecom)	South Korea	Before monitoring	2026-11-08 12:23	Announcing
221.159.210.0/24	AS55622	CNUE	South Korea	Before monitoring	2026-11-08 12:23	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: APNIC
Allocated block: 221.144.0.0/12
Country: South Korea
Allocation date: 2003-04-17
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.