`21maths.com`

DNSSEC	⚠️ Not signed
A	218.85.139.47^{🇨🇳 CHINATELECOM-Fujian-Xiamen-IDC1218.85.136.0/22 IDC FUJIAN XIAMEN}
NS	`dns9.hichina.com` ⭐
		A	2408:4009:501::17^{🇨🇳 Alibaba-Cloud2408:4009:501::/48}
		A	39.96.153.42^{🇨🇳 Alibaba-Cloud39.96.0.0/14 CT BeiJing IDC}
		A	39.96.153.52^{🇨🇳 Alibaba-Cloud39.96.0.0/14 CT BeiJing IDC}
		A	47.118.199.202^{🇨🇳 Alibaba-Cloud47.118.128.0/17 Alibaba (US) Technology Co., Ltd.}
		A	47.118.199.212^{🇨🇳 Alibaba-Cloud47.118.128.0/17 Alibaba (US) Technology Co., Ltd.}
		A	120.76.107.42^{🇨🇳 Alibaba-Cloud120.76.0.0/17}
		A	120.76.107.52^{🇨🇳 Alibaba-Cloud120.76.0.0/17}
		A	139.224.142.112^{🇨🇳 Alibaba-Cloud139.224.128.0/17 China Internet Network Information Center Floor1, Building No.1 C/-Chinese Academy of Sciences 4, South 4th Street Haidian District,}
		A	139.224.142.122^{🇨🇳 Alibaba-Cloud139.224.128.0/17 China Internet Network Information Center Floor1, Building No.1 C/-Chinese Academy of Sciences 4, South 4th Street Haidian District,}
NS	`dns10.hichina.com`
		A	2408:4009:501::18^{🇨🇳 Alibaba-Cloud2408:4009:501::/48}
		A	39.96.153.41^{🇨🇳 Alibaba-Cloud39.96.0.0/14 CT BeiJing IDC}
		A	39.96.153.51^{🇨🇳 Alibaba-Cloud39.96.0.0/14 CT BeiJing IDC}
		A	47.118.199.201^{🇨🇳 Alibaba-Cloud47.118.128.0/17 Alibaba (US) Technology Co., Ltd.}
		A	47.118.199.211^{🇨🇳 Alibaba-Cloud47.118.128.0/17 Alibaba (US) Technology Co., Ltd.}
		A	120.76.107.41^{🇨🇳 Alibaba-Cloud120.76.0.0/17}
		A	120.76.107.51^{🇨🇳 Alibaba-Cloud120.76.0.0/17}
		A	139.224.142.111^{🇨🇳 Alibaba-Cloud139.224.128.0/17 China Internet Network Information Center Floor1, Building No.1 C/-Chinese Academy of Sciences 4, South 4th Street Haidian District,}
		A	139.224.142.121^{🇨🇳 Alibaba-Cloud139.224.128.0/17 China Internet Network Information Center Floor1, Building No.1 C/-Chinese Academy of Sciences 4, South 4th Street Haidian District,}
MX	`mxdomain.qq.com` ⭐
SOA	`dns9.hichina.com`hostmaster@hichina.com 2026-01-09 #13

`com`

	DNSSEC	🔒 Signed (DS record present)
	NS	`a.gtld-servers.net` ⭐
	NS	`b.gtld-servers.net`
	NS	`c.gtld-servers.net`
	NS	`d.gtld-servers.net`
	NS	`e.gtld-servers.net`
	NS	`f.gtld-servers.net`
	NS	`g.gtld-servers.net`
	NS	`h.gtld-servers.net`
	NS	`i.gtld-servers.net`
	NS	`j.gtld-servers.net`
	NS	`k.gtld-servers.net`
	NS	`l.gtld-servers.net`
	NS	`m.gtld-servers.net`
	SOA	`a.gtld-servers.net`nstld@verisign-grs.com serial=1776102762

WOT: SAFE (68/100)

Same first word

21maths.com

DNS History

6 records (4 active, 2 former)

●NSdns10.hichina.com2017-07-17 → 2026-04-13 · 3 obs

○ 2017-05-31 22:45:30
● 2017-07-17 08:42:22
● 2026-04-13 18:01:22

○NSdns13.hichina.com2015-08-14 → 2017-05-31 · 4 obs

● 2015-08-14 23:12:56
● 2017-05-31 22:45:30
○ 2017-07-17 08:42:22
○ 2026-04-13 18:01:22

○NSdns14.hichina.com2015-08-14 → 2017-05-31 · 4 obs

● 2015-08-14 23:12:56
● 2017-05-31 22:45:30
○ 2017-07-17 08:42:22
○ 2026-04-13 18:01:22

●NSdns9.hichina.com2017-07-17 → 2026-04-13 · 3 obs

○ 2017-05-31 22:45:30
● 2017-07-17 08:42:22
● 2026-04-13 18:01:22

●MXmxdomain.qq.com2015-08-14 → 2026-04-13 · 2 obs

● 2015-08-14 23:12:56
● 2026-04-13 18:01:22

●A218.85.139.472015-08-14 → 2026-04-13 · 2 obs

● 2015-08-14 23:12:56
● 2026-04-13 18:01:22

🔍 DNS Trace

📋 Delegation Chain

Zone	Nameservers	Glue
com	h.gtld-servers.net, k.gtld-servers.net, i.gtld-servers.net, g.gtld-servers.net...	-
21maths.com	dns9.hichina.com, dns10.hichina.com	18 records

✅ Authoritative Response

Server:47.118.199.211

NS records: dns9.hichina.com, dns10.hichina.com

🔒 DNSSEC Status

⚠️ Insecure (no DNSSEC)

No DS record for 21maths.com (unsigned zone)

⏱️ Timing

Total: 540ms | Queries: -

📄 Records

Type	Count	Sample Data
A	1	`218.85.139.47`
NS	2	`dns10.hichina.com, dns9.hichina.com`
MX	1	`mxdomain.qq.com (pri: 10)`
SOA	1	`dns9.hichina.com hostmaster.hichina.com`

📌 Glue Records Collected

Total: 18

Out-of-bailiwick: 18 (dns9.hichina.com, dns9.hichina.com, dns9.hichina.com...)

Analysis

IP Addresses

21maths.com points to IP number 218.85.139.47.

Name Servers

21maths.com is delegated to two name servers: dns10.hichina.com and dns9.hichina.com.

21maths.com uses the same name server setup as other domains such as chuanjiemen.com, ytskjx.com, xyzhapi.com, sinogene.com.cn and tiit.cn.

21maths.com shares name servers with other domains at least partially, for example ylrl.com, jifenchaoshi.com, cohome.cn, lzti.cn and gwell.com.cn.

These name servers are commonly used with the name servers expirens3.hichina.com and expirens4.hichina.com.

Host names with nine IP numbers:

dns10.hichina.com points to: 2408:4009:501::18, 39.96.153.41, 39.96.153.51, 47.118.199.201, 47.118.199.211, 120.76.107.41, 120.76.107.51, 139.224.142.111 and 139.224.142.121.

dns9.hichina.com points to: 2408:4009:501::17, 39.96.153.42, 39.96.153.52, 47.118.199.202, 47.118.199.212, 120.76.107.42, 120.76.107.52, 139.224.142.112 and 139.224.142.122.

Mail Servers

21maths.com is handled by a single mail server, mxdomain.qq.com.

21maths.com shares the same mail server setup as other domains, for instance dm339.com, vnlee.com, bluetex.com, huidezhou.com and lvpnl.com.

21maths.com shares some mail servers with other domains, at least partially; examples include bilibili.co, vyin.cn and lenpaby.com.

21maths.com - robtex.com

21maths.com

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