`51du.org`

DNSSEC	⚠️ Not signed
A	2606:4700:3033::6815:a22^{🇺🇸 Cloudflare2606:4700:3033::/48 , Inc. 101 Townsend Street, San Francisco, California 94107, US} ✓ In HTTPS hints
A	2606:4700:3035::ac43:bde3^{🇺🇸 Cloudflare2606:4700:3035::/48 , Inc. 101 Townsend Street, San Francisco, California 94107, US} ✓ In HTTPS hints
A	104.21.10.34^{Cloudflare104.21.0.0/20 , Inc. 101 Townsend Street, San Francisco, California 94107, US} ✓ In HTTPS hints
A	172.67.189.227^{🇺🇸 Cloudflare172.67.176.0/20 , Inc. 101 Townsend Street, San Francisco, California 94107, US} ✓ In HTTPS hints
NS	`emma.ns.cloudflare.com` ⭐
		A	2606:4700:50::adf5:3a70^{🇺🇸 Cloudflare2606:4700:50::/44 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`emma.ns.cloudflare.com`
		A	2803:f800:50::6ca2:c070^{🇨🇷 Cloudflare2803:f800:50::/45 LACNIC generated route6 for CloudFlare Latin America S.R.L}
			PTR	`emma.ns.cloudflare.com`
		A	2a06:98c1:50::ac40:2070^{🇺🇸 Cloudflare2a06:98c1:50::/45}
			PTR	`emma.ns.cloudflare.com`
		A	108.162.192.112^{🇺🇸 Cloudflare108.162.192.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`emma.ns.cloudflare.com`
		A	172.64.32.112^{🇺🇸 Cloudflare172.64.32.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`emma.ns.cloudflare.com`
		A	173.245.58.112^{🇺🇸 Cloudflare173.245.58.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`emma.ns.cloudflare.com`
NS	`rob.ns.cloudflare.com`
		A	2606:4700:58::adf5:3b8c^{🇺🇸 Cloudflare2606:4700:50::/44 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`rob.ns.cloudflare.com`
		A	2803:f800:50::6ca2:c18c^{🇨🇷 Cloudflare2803:f800:50::/45 LACNIC generated route6 for CloudFlare Latin America S.R.L}
			PTR	`rob.ns.cloudflare.com`
		A	2a06:98c1:50::ac40:218c^{🇺🇸 Cloudflare2a06:98c1:50::/45}
			PTR	`rob.ns.cloudflare.com`
		A	108.162.193.140^{🇺🇸 Cloudflare108.162.193.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`rob.ns.cloudflare.com`
		A	172.64.33.140^{🇺🇸 Cloudflare172.64.33.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`rob.ns.cloudflare.com`
		A	173.245.59.140^{🇺🇸 Cloudflare173.245.59.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`rob.ns.cloudflare.com`
TXT	`google-site-verification=ZWsTpakl2zlFUGflHDb4s6CkzkEnL-NTiQqirAXC_tw`
HTTPS	HTTP/3, HTTP/2 ✓ hints match
		IPv4	104.21.10.34, 172.67.189.227
		IPv6	2606:4700:3033::6815:a22, 2606:4700:3035::ac43:bde3
SOA	`emma.ns.cloudflare.com`dns@cloudflare.com serial=2398558354

`org`

	DNSSEC	🔒 Signed (DS record present)
	NS	`a0.org.afilias-nst.info` ⭐ ⚠️ Not in parent delegation
	NS	`a2.org.afilias-nst.info` ⚠️ Not in parent delegation
	NS	`b0.org.afilias-nst.org`
	NS	`b2.org.afilias-nst.org`
	NS	`c0.org.afilias-nst.info` ⚠️ Not in parent delegation
	NS	`d0.org.afilias-nst.org`
	SOA	`a0.org.afilias-nst.info`hostmaster@donuts.email serial=1773551953

Subdomains

m.51du.org

Same first word

51du.cc

51du.com

51du.org

Similar names

du51.cn

DNS History

12 records (6 active, 6 former)

●NSemma.ns.cloudflare.com2026-02-26 → 2026-03-23 · 2 obs

● 2026-02-26 12:57:28
● 2026-03-23 15:37:58

●NSrob.ns.cloudflare.com2026-02-26 → 2026-03-23 · 2 obs

● 2026-02-26 12:57:28
● 2026-03-23 15:37:58

○MXmail.skrimple.com2015-11-19 → 2015-11-19 · 3 obs

● 2015-11-19 06:30:06
○ 2016-03-02 21:19:26
○ 2026-03-23 15:37:58

●A104.21.10.342026-02-26 → 2026-03-23 · 60 obs

○ 2016-03-02 21:19:26
● 2026-02-26 12:57:28
● 2026-02-27 15:27:40
○ 2026-02-28 00:15:06
● 2026-02-28 01:01:42
● 2026-03-03 04:13:06
○ 2026-03-04 01:29:54
● 2026-03-04 02:11:50
● 2026-03-05 06:05:12
○ 2026-03-05 06:42:48
○ 2026-03-06 14:57:24
● 2026-03-06 17:45:44
● 2026-03-07 01:53:28
○ 2026-03-07 03:38:44
● 2026-03-07 16:02:06
○ 2026-03-07 17:18:38
● 2026-03-07 22:10:14
● 2026-03-08 05:13:44
○ 2026-03-08 06:50:18
● 2026-03-08 13:06:42
○ 2026-03-08 21:52:14
● 2026-03-09 05:11:28
○ 2026-03-09 10:46:58
○ 2026-03-10 03:09:32
● 2026-03-10 04:41:14
○ 2026-03-10 11:37:18
● 2026-03-10 20:53:34
○ 2026-03-11 13:04:24
○ 2026-03-12 04:27:12
● 2026-03-12 21:55:14
○ 2026-03-13 02:09:54
● 2026-03-13 04:22:00
● 2026-03-13 14:33:40
○ 2026-03-13 15:30:48
○ 2026-03-14 04:21:40
● 2026-03-14 05:07:42
○ 2026-03-14 17:28:58
○ 2026-03-15 02:48:10
● 2026-03-15 04:04:04
○ 2026-03-15 06:23:46
○ 2026-03-17 05:02:46
● 2026-03-17 18:33:02
○ 2026-03-17 21:10:50
○ 2026-03-18 04:19:42
● 2026-03-18 16:42:36
○ 2026-03-18 18:45:16
○ 2026-03-19 01:42:28
● 2026-03-19 04:28:44
○ 2026-03-19 11:21:00
● 2026-03-19 20:35:16
○ 2026-03-19 23:39:24
● 2026-03-20 03:37:48
● 2026-03-20 04:14:56
○ 2026-03-20 12:10:30
○ 2026-03-21 02:33:16
● 2026-03-21 11:26:52
○ 2026-03-22 01:28:42
○ 2026-03-23 04:42:52
● 2026-03-23 06:13:30
● 2026-03-23 15:37:58

●A172.67.189.2272026-02-26 → 2026-03-23 · 60 obs

○A184.105.178.922015-11-19 → 2015-11-19 · 3 obs

● 2015-11-19 06:30:06
○ 2016-03-02 21:19:26
○ 2026-03-23 15:37:58

○A188.114.96.02026-02-28 → 2026-03-23 · 59 obs

○ 2026-02-26 12:57:28
○ 2026-02-27 15:27:40
● 2026-02-28 00:15:06
○ 2026-02-28 01:01:42
○ 2026-03-03 04:13:06
● 2026-03-04 01:29:54
○ 2026-03-04 02:11:50
○ 2026-03-05 06:05:12
● 2026-03-05 06:42:48
● 2026-03-06 14:57:24
○ 2026-03-06 17:45:44
○ 2026-03-07 01:53:28
● 2026-03-07 03:38:44
○ 2026-03-07 16:02:06
● 2026-03-07 17:18:38
○ 2026-03-07 22:10:14
○ 2026-03-08 05:13:44
● 2026-03-08 06:50:18
○ 2026-03-08 13:06:42
● 2026-03-08 21:52:14
○ 2026-03-09 05:11:28
● 2026-03-09 10:46:58
● 2026-03-10 03:09:32
○ 2026-03-10 04:41:14
● 2026-03-10 11:37:18
○ 2026-03-10 20:53:34
● 2026-03-11 13:04:24
● 2026-03-12 04:27:12
○ 2026-03-12 21:55:14
● 2026-03-13 02:09:54
○ 2026-03-13 04:22:00
○ 2026-03-13 14:33:40
● 2026-03-13 15:30:48
● 2026-03-14 04:21:40
○ 2026-03-14 05:07:42
● 2026-03-14 17:28:58
● 2026-03-15 02:48:10
○ 2026-03-15 04:04:04
● 2026-03-15 06:23:46
● 2026-03-17 05:02:46
○ 2026-03-17 18:33:02
● 2026-03-17 21:10:50
● 2026-03-18 04:19:42
○ 2026-03-18 16:42:36
● 2026-03-18 18:45:16
● 2026-03-19 01:42:28
○ 2026-03-19 04:28:44
● 2026-03-19 11:21:00
○ 2026-03-19 20:35:16
● 2026-03-19 23:39:24
○ 2026-03-20 03:37:48
○ 2026-03-20 04:14:56
● 2026-03-20 12:10:30
● 2026-03-21 02:33:16
○ 2026-03-21 11:26:52
● 2026-03-22 01:28:42
● 2026-03-23 04:42:52
○ 2026-03-23 06:13:30
○ 2026-03-23 15:37:58

○A188.114.97.02026-02-28 → 2026-03-23 · 59 obs

●A2606:4700:3033::6815:a222026-02-26 → 2026-03-23 · 60 obs

●A2606:4700:3035::ac43:bde32026-02-26 → 2026-03-23 · 60 obs

○A2a06:98c1:3120::2026-02-28 → 2026-03-23 · 59 obs

○A2a06:98c1:3121::2026-02-28 → 2026-03-23 · 59 obs

🔍 DNS Trace

📋 Delegation Chain

Zone	Nameservers	Glue
org	b2.org.afilias-nst.org, d0.org.afilias-nst.org, b0.org.afilias-nst.org	-
51du.org	rob.ns.cloudflare.com, emma.ns.cloudflare.com	-

✅ Authoritative Response

Server:108.162.192.112

NS records: rob.ns.cloudflare.com, emma.ns.cloudflare.com

🔒 DNSSEC Status

⚠️ Insecure (no DNSSEC)

No DS record for 51du.org (unsigned zone)

⏱️ Timing

Total: 431ms | Queries: -

📄 Records

Type	Count	Sample Data
A	2	`104.21.10.34, 172.67.189.227`
AAAA	2	`2606:4700:3033::6815:a22, 2606:4700:3035::ac43:bde3`
NS	2	`emma.ns.cloudflare.com, rob.ns.cloudflare.com`
TXT	1	`google-site-verification=ZWsTpakl2zlFUGf`
HTTPS	1	`{"priority":1,"target":".","alpn":["h3",`
SOA	1	`emma.ns.cloudflare.com dns.cloudflare.co`

Analysis

Hierarchy

m.51du.org is a child of 51du.org.

IP Addresses

51du.org refers to four IP numbers: 2606:4700:3033::6815:a22, 2606:4700:3035::ac43:bde3, 104.21.10.34 and 172.67.189.227.

Other host names, for instance anjibaiquan.com, ultahooosttt.sbs, cannbix.com, theaea.org and akep.al share IP numbers with 51du.org.

Name Servers

51du.org's delegation uses two name servers: emma.ns.cloudflare.com and rob.ns.cloudflare.com.

51du.org uses the same name server setup as other domains, such as nationalhyperbariccentre.com, s-mania.at, leo.pw, ixunshu.net and metanovel.org.

51du.org at least partially shares name servers with other domains, including slime.lol, dkohata.cn, iag-usa.com, thecurrencycalculator.com and tlm.solutions.

These name servers are often used with fred.ns.cloudflare.com and mary.ns.cloudflare.com.

Host names with six IP numbers:

emma.ns.cloudflare.com points to 2606:4700:50::adf5:3a70, 2803:f800:50::6ca2:c070, 2a06:98c1:50::ac40:2070, 108.162.192.112, 172.64.32.112 and 173.245.58.112.

rob.ns.cloudflare.com points to 2606:4700:58::adf5:3b8c, 2803:f800:50::6ca2:c18c, 2a06:98c1:50::ac40:218c, 108.162.193.140, 172.64.33.140 and 173.245.59.140.

51du.org - robtex.com

51du.org

org