AS17421 Data Communication Business Group,

AS17421Data Communication Business Group,ISP

WHOIS Topology

Taiwan · APNICcht.com.tw

Home broadband

IPv4 addresses

1,655,808

191 announced prefixes

IPv6 addresses

4.05 × 10³¹

34 announced prefixes

BGP neighbours

…

CAIDA rank

#12,930

Customer cone 1 ASNs

Estimated users

4.52M

APNIC: 4.52M

RPKI

100% valid

0 invalid · 0 not covered

Average purity

83 sampled IPs

IXPs / facilities

0 / 0

Operator self-reported

History

How prefixes were announced and changed hands, registration changes, and outage or hijack incidents.

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IP ranges

Currently announced prefixes with their RIR registration and geolocation.

Prefix	RPKI	Registration	Geolocation	Addresses
42.74.0.0/16	Valid	EMOME-NETAPNIC	Kaohsiung	65,536
42.75.0.0/16	Valid	EMOME-NETAPNIC	Kaohsiung	65,536
111.80.0.0/16	Valid	EMOME-NETAPNIC	Xinyi	65,536
42.73.0.0/17	Valid	EMOME-NETAPNIC	Taoyuan	32,768
42.73.128.0/17	Valid	EMOME-NETAPNIC	Taoyuan	32,768
42.79.0.0/17	Valid	EMOME-NETAPNIC	Taoyuan	32,768
111.82.0.0/17	Valid	EMOME-NETAPNIC	Taichung	32,768
111.82.128.0/17	Valid	EMOME-NETAPNIC	Taichung	32,768
223.143.0.0/17	Valid	EMOME-NETAPNIC	Taipei	32,768
42.70.0.0/18	Valid	EMOME-NETAPNIC	New Taipei City	16,384
42.70.64.0/18	Valid	EMOME-NETAPNIC	New Taipei City	16,384
42.70.128.0/18	Valid	EMOME-NETAPNIC	New Taipei City	16,384
42.70.192.0/18	Valid	EMOME-NETAPNIC	New Taipei City	16,384
42.71.0.0/18	Valid	EMOME-NETAPNIC	Taichung	16,384
42.71.64.0/18	Valid	EMOME-NETAPNIC	Changhua	16,384
42.71.128.0/18	Valid	EMOME-NETAPNIC	Dacun	16,384
42.71.192.0/18	Valid	EMOME-NETAPNIC	Xiushui	16,384
42.72.0.0/18	Valid	EMOME-NETAPNIC	Hsinchu	16,384
42.72.64.0/18	Valid	EMOME-NETAPNIC	Hsinchu	16,384
42.72.128.0/18	Valid	EMOME-NETAPNIC	Taoyuan	16,384

/24 block profile

One square per /24: colour shows the risk type, shade how many addresses are flagged, stripes mark datacenter blocks. Click a square to see all 256 addresses.

/24s with data 118 / 6,468 （2%） · flagged 70

No risk flagsDatacenter (no flags)ProxyVPNAbuse / blocklistTorDarker = more flagged addresses; dashed = block screen only

111.70.0.0/1840/64 with data · 40 flagged

221.120.0.0/218/8 with data · 8 flagged

114.137.192.0/184/64 with data · 0 flagged

42.74.0.0/163/256 with data · 0 flagged

114.136.128.0/183/64 with data · 1 flagged

116.59.12.0/223/4 with data · 3 flagged

42.75.0.0/162/256 with data · 0 flagged

111.80.0.0/162/256 with data · 0 flagged

42.73.0.0/172/128 with data · 0 flagged

42.79.0.0/172/128 with data · 0 flagged

111.82.0.0/172/128 with data · 0 flagged

42.71.128.0/182/64 with data · 0 flagged

Hover a square for its numbers; click to see all 256 addresses.

Each prefix shows its 64 /24s with the most data. Built daily from lookups, neighbour sampling, public lists and block screening.

IP reputation

IPs from this network that CleanIP has analysed: purity, abuse reports and the riskiest /24 blocks.

Purity distribution

85–100 6870–84 750–69 80–49 0

0.05%

Share of IPv4 reported or blocklisted

798

Listed IPs

Analysed IPs

Flagged = VPN, proxy, Tor or purity below 50. Samples come from user lookups and neighbour sampling, not every address in this network.

Geography

Where this network’s IPv4 addresses are located.

Taiwan100.0%

Scope: Single country
In registered country: 100.0%

Estimated by sampling IPv4 ranges against a geolocation database.

Traffic observation

AS17421 · Last 7 days

Mobile vs. Desktop

Desktop34.1%Mobile65.9%

Bot vs. Human

Human91.2%Bot8.8%

Adoption & Usage

Adoption and usage of key protocols

HTTP Version

HTTP/1.x

8.9%HTTP/2

57.3%HTTP/3

33.8%

HTTP vs. HTTPS

99.4% HTTPS (encrypted)

Plain HTTP 0.6%

TLS Version

TLS 1.0/1.1< 0.1%TLS 1.24.7%TLS 1.361.3%QUIC34.0%

Security & Attacks

Insights into network and application layer attack traffic

Layer 7 Attacks

GET

77.1%POST

15.3%HEAD

6.3%PUT

0.9%OPTIONS

0.3%Other

0.1%

BGP Announcements

Hourly BGP route announcements over the last 7 days

1,095,547

7-day total

66,161

Hourly peak

Data: Cloudflare Radar, licensed under CC BY-NC 4.0

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BGP upstreams and neighbours

AS17421Standalone page

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WHOIS record

The registry’s record for this AS number: holder, status, dates and contacts.

Sources

Where the information on this page comes from and when it was updated.

Information	Source	Updated
Registered country	RIR daily delegation statistics	2026-10-22
Registered address & allocation date	RIR registration data (RDAP)	2026-10-08
Organization & company country	AS-to-organization data	2026-10-21
Network type	CleanIP ASN canon	2026-10-21
Announced prefixes & BGP neighbours	Public BGP routing data	2026-10-22
IPv4 geography	Geolocation database	—
RPKI validation	RPKI ROA validation data	2026-10-22
Rank & customer cone	CAIDA AS Rank	2026-10-01
Estimated users (APNIC)	APNIC Labs user estimates	2026-10-19
Network tags	Public routing data community tags	2026-10-22
IP reputation	CleanIP lookups and neighbour sampling	—

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Multi-source cross-checks · In-house reputation data · Real data only