123.51.128.0/17

Currently announced by AS9919 New Century InfoComm Tech Co., Ltd., in the routed prefix 123.51.128.0/17.

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

Routing data · Nov 1, 2026, 20:20 UTC

ASN historyEvery routed prefix covering 123.51.128.0/17

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

More specific routes110 total

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
123.51.128.0/19	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
123.51.192.0/18	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.192.0/19	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.193.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.194.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.195.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.196.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.197.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.198.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.199.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.200.0/23	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.200.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.202.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.206.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.208.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.211.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.213.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.215.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.216.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.217.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.218.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.219.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.220.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.221.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.222.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.223.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.224.0/19	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.224.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.225.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.226.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.227.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.228.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.229.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.230.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.231.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.232.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.233.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.234.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.235.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.236.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.237.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.238.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.239.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.241.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.244.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.245.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.246.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.247.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.248.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.249.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.250.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.251.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.253.0/24	AS4780	New Century InfoComm Tech Co.,Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.254.0/24	AS9919	New Century InfoComm Tech Co., Ltd.	Taiwan	Before monitoring	2026-11-01 20:20	Announcing
123.51.255.0/24	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.