123.51.128.0/18

Currently announced by AS9919 New Century InfoComm Tech Co., Ltd., in the routed prefix 123.51.128.0/18.

Current ASN: AS9919; New Century InfoComm Tech Co., Ltd.
Routed prefix: 123.51.128.0/18; Most specific route covering this prefix
ASNs over time: 1; 2 announcement records
RIR allocation: APNIC; Taiwan · 123.51.128.0/17

Routing data · Nov 1, 2026, 20:20 UTC

ASN historyEvery routed prefix covering 123.51.128.0/18

Prefix	ASN	Name	Registered country	First seen (UTC)	Last seen (UTC)	Status
123.51.128.0/18	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.128.0/17	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing

More specific routes55 total

Prefix	ASN	Name	Registered country	First seen (UTC)	Last seen (UTC)	Status
123.51.128.0/19	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.128.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.129.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.130.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.131.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.132.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.133.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.134.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.135.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.136.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.140.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.141.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.142.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.143.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.144.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.145.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.146.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.147.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.148.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.149.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.150.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.151.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.152.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.153.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.154.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.155.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.156.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.157.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.158.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.159.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.160.0/19	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.160.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.161.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.162.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.163.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.164.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.165.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.166.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.167.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.168.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.169.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.170.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.171.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.172.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.173.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.174.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.175.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.176.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.178.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.182.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.183.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.184.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.188.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.190.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.154.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	2026-10-30 22:21	2026-10-31 08:19	Stopped

Change logAll changes

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

Look up another address

RIR allocation record

Registry: APNIC
Allocated block: 123.51.128.0/17
Country: Taiwan
Allocation date: 2008-11-20
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.