c21.com.hk - robtex.com
c21.com.hk
| DNSSEC | ⚠️ Not signed | ||||||
| A | 218.189.79.15🇭🇰 HUTCHISON-AS-AP218.189.64.0/19 | ||||||
| NS | ns1.hkbn.net ⭐ | ||||||
| A | 203.80.96.8 | ||||||
| NS | ns2.hkbn.net | ||||||
| A | 203.186.94.21 | ||||||
| MX | c21-com-hk.mail.protection.outlook.com ⭐ | ||||||
| A | 2a01:111:f403:cc09::🇸🇬 Microsoft2a01:111:f000::/36 | ||||||
| A | 2a01:111:f403:cc1a::8🇯🇵 Microsoft2a01:111:f000::/36 | ||||||
| PTR | mail-tydpr03cu00100.inbound.protection.outlook.com | ||||||
| A | 2a01:111:f403:cc1f::4🇯🇵 Microsoft2a01:111:f000::/36 | ||||||
| PTR | mail-os8pr02cu00104.inbound.protection.outlook.com | ||||||
| A | 52.101.124.117🇯🇵 Microsoft52.96.0.0/12 MICROSOFT | ||||||
| PTR | mail-tydpr03cu00105.inbound.protection.outlook.com | ||||||
| A | 52.101.137.0🇸🇬 Microsoft52.96.0.0/12 MICROSOFT | ||||||
| PTR | mail-sg2pr03cu00500.inbound.protection.outlook.com | ||||||
| A | 52.101.157.80🇺🇸 Microsoft52.96.0.0/12 MICROSOFT | ||||||
| PTR | mail-os8pr02cu00100.inbound.protection.outlook.com | ||||||
| TXT | v=spf1 include:spf.protection.outlook.com -all | ||||||
| TXT | MS=ms60893412 | ||||||
| SOA | ns1.hkbn.netsysadm@ns1.hkbn.net 2026-01-28 #1 | ||||||
com.hk
| DNSSEC | ⚠️ Not signed | ||||||
| NS | ns3.hkirc.net.hk ⭐ | ||||||
| NS | c.hkirc.net.hk ⚠️ Not in parent delegation | ||||||
| NS | d.hkirc.net.hk ⚠️ Not in parent delegation | ||||||
| NS | m.hkirc.net.hk ⚠️ Not in parent delegation | ||||||
| NS | t.hkirc.net.hk ⚠️ Not in parent delegation | ||||||
| NS | u.hkirc.net.hk ⚠️ Not in parent delegation | ||||||
| NS | v.hkirc.net.hk ⚠️ Not in parent delegation | ||||||
| NS | x.hkirc.net.hk ⚠️ Not in parent delegation | ||||||
| NS | y.hkirc.net.hk ⚠️ Not in parent delegation | ||||||
| NS | z.hkirc.net.hk ⚠️ Not in parent delegation | ||||||
| SOA | ns3.hkirc.net.hkhostmaster@hkirc.net.hk serial=2073598880 | ||||||
Subdomains
Same first word
Similar names
Previous names
Next names
DNS History
14 records (4 active, 10 former)
○NSns1.c21.com.hk2015-07-06 → 2017-05-13 · 4 obs
● 2017-05-13 18:49:44
○ 2026-02-17 03:47:56
○ 2026-10-18 11:01:48
●NSns1.hkbn.net2026-02-17 → 2026-10-18 · 3 obs
● 2026-02-17 03:47:56
● 2026-10-18 11:01:48
●NSns2.hkbn.net2026-02-17 → 2026-10-18 · 3 obs
● 2026-02-17 03:47:56
● 2026-10-18 11:01:48
○MXalt1.aspmx.l.google.com2015-07-06 → 2017-05-13 · 4 obs
● 2017-05-13 18:49:44
○ 2026-02-17 03:47:56
○ 2026-10-18 11:01:48
○MXalt2.aspmx.l.google.com2015-07-06 → 2017-05-13 · 4 obs
● 2017-05-13 18:49:44
○ 2026-02-17 03:47:56
○ 2026-10-18 11:01:48
○MXaspmx.l.google.com2015-07-06 → 2017-05-13 · 4 obs
● 2017-05-13 18:49:44
○ 2026-02-17 03:47:56
○ 2026-10-18 11:01:48
○MXaspmx2.googlemail.com2015-07-06 → 2017-05-13 · 4 obs
● 2017-05-13 18:49:44
○ 2026-02-17 03:47:56
○ 2026-10-18 11:01:48
○MXaspmx3.googlemail.com2015-07-06 → 2017-05-13 · 4 obs
● 2017-05-13 18:49:44
○ 2026-02-17 03:47:56
○ 2026-10-18 11:01:48
○MXaspmx4.googlemail.com2015-07-06 → 2017-05-13 · 4 obs
● 2017-05-13 18:49:44
○ 2026-02-17 03:47:56
○ 2026-10-18 11:01:48
○MXaspmx5.googlemail.com2015-07-06 → 2017-05-13 · 4 obs
● 2017-05-13 18:49:44
○ 2026-02-17 03:47:56
○ 2026-10-18 11:01:48
●MXc21-com-hk.mail.protection.outlook.com2026-02-17 → 2026-10-18 · 3 obs
● 2026-02-17 03:47:56
● 2026-10-18 11:01:48
○MXmail.c21.com.hk2015-07-06 → 2017-05-13 · 4 obs
● 2017-05-13 18:49:44
○ 2026-02-17 03:47:56
○ 2026-10-18 11:01:48
●A218.189.79.152026-02-17 → 2026-10-18 · 3 obs
● 2026-02-17 03:47:56
● 2026-10-18 11:01:48
○A59.188.137.2072015-07-06 → 2017-05-13 · 4 obs
● 2017-05-13 18:49:44
○ 2026-02-17 03:47:56
○ 2026-10-18 11:01:48
🔍 DNS Trace
📋 Delegation Chain
| Zone | Nameservers | Glue |
|---|---|---|
| hk | u.hkirc.net.hk, c.hkirc.net.hk, t.hkirc.net.hk, d.hkirc.net.hk... | 15 records |
| c21.com.hk | ns1.hkbn.net, ns2.hkbn.net | - |
✅ Authoritative Response
Server:203.186.94.21
NS records: ns1.hkbn.net, ns2.hkbn.net
🔒 DNSSEC Status
⚠️ Insecure (no DNSSEC)
No DS record for c21.com.hk (unsigned zone)
⏱️ Timing
Total: 2423ms | Queries: -
📄 Records
| Type | Count | Sample Data |
|---|---|---|
| A | 1 | 218.189.79.15 |
| NS | 2 | ns1.hkbn.net, ns2.hkbn.net |
| MX | 1 | c21-com-hk.mail.protection.outlook.com ( |
| TXT | 2 | v=spf1 include:spf.protection.outlook.co, MS=ms60893412 |
| SOA | 1 | ns1.hkbn.net sysadm.ns1.hkbn.net |
📌 Glue Records Collected
Total: 15
In-bailiwick: 15 (c.hkirc.net.hk, d.hkirc.net.hk, m.hkirc.net.hk...)
Analysis
Hierarchy
The parent domain of mail.c21.com.hk and ns1.c21.com.hk is c21.com.hk.
IP Addresses
c21.com.hk directs to one IP number, which is 218.189.79.15.
Among the host names that share IP numbers with c21.com.hk are bestfortune.com.hk, lpal.com.hk, www.fullmark.hk and two others.
Name Servers
DNS delegation for c21.com.hk points to two name servers: ns1.hkbn.net and ns2.hkbn.net.
c21.com.hk has the same name server delegation as a number of other domains, such as 176.244.124.in-addr.arpa, 44.199.14.in-addr.arpa, 124.199.14.in-addr.arpa and two more.
c21.com.hk has at least partial name server overlap with other domains, such as 27.185.203.in-addr.arpa, 86.198.14.in-addr.arpa, velvet.com.hk and two others.
These name servers are often used together with the name servers ns1o.ctihk.com and ns2o.ctihk.com.
ns1.hkbn.net directs to 203.80.96.8 and ns2.hkbn.net directs to 203.186.94.21; each host name points to exactly one IP number.
Mail Servers
c21.com.hk routes its mail through a single mail server, c21-com-hk.mail.protection.outlook.com.
c21-com-hk.mail.protection.outlook.com directs to 6 IP numbers, including 52.101.124.117, 52.101.137.0 and 52.101.157.80, along with 3 other.