21thcentury.com - robtex.com
21thcentury.com
| DNSSEC | ⚠️ Not signed | ||||||
| A | 3.21.30.236🇺🇸 Amazon3.20.0.0/14 EC2 CMH prefix | ||||||
| PTR | ec2-3-21-30-236.us-east-2.compute.amazonaws.com | ||||||
| A | 3.138.52.249🇺🇸 Amazon3.136.0.0/13 EC2 CMH prefix | ||||||
| NS | ns-1260.awsdns-29.org ⭐ | ||||||
| A | 2600:9000:5304:ec00::1🇺🇸 Amazon2600:9000:5304::/48 - CloudFront | ||||||
| PTR | ns-1260.awsdns-29.org | ||||||
| A | 205.251.196.236🇺🇸 Amazon205.251.196.0/24 prefix | ||||||
| PTR | ns-1260.awsdns-29.org | ||||||
| NS | ns-1942.awsdns-50.co.uk | ||||||
| A | 2600:9000:5307:9600::1🇺🇸 Amazon2600:9000:5307::/48 - CloudFront | ||||||
| PTR | ns-1942.awsdns-50.co.uk | ||||||
| A | 205.251.199.150🇺🇸 Amazon205.251.199.0/24 prefix | ||||||
| PTR | ns-1942.awsdns-50.co.uk | ||||||
| NS | ns-277.awsdns-34.com | ||||||
| A | 2600:9000:5301:1500::1🇺🇸 Amazon2600:9000:5301::/48 - CloudFront | ||||||
| PTR | ns-277.awsdns-34.com | ||||||
| A | 205.251.193.21🇺🇸 Amazon205.251.193.0/24 prefix | ||||||
| PTR | ns-277.awsdns-34.com | ||||||
| NS | ns-990.awsdns-59.net | ||||||
| A | 2600:9000:5303:de00::1🇺🇸 Amazon2600:9000:5303::/48 - CloudFront | ||||||
| PTR | ns-990.awsdns-59.net | ||||||
| A | 205.251.195.222🇺🇸 Amazon205.251.195.0/24 prefix | ||||||
| PTR | ns-990.awsdns-59.net | ||||||
| SOA | ns-1260.awsdns-29.orgawsdns-hostmaster@amazon.com serial=1 | ||||||
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.netnstld@verisign-grs.com serial=1778246407 | ||||||
Same first word
21thcentury.com |
DNS History
12 records (6 active, 6 former)
●NSns-1260.awsdns-29.org2026-05-05 → 2026-05-08 · 3 obs
● 2026-05-05 12:25:06
● 2026-05-08 13:38:04
●NSns-1942.awsdns-50.co.uk2026-05-05 → 2026-05-08 · 3 obs
● 2026-05-05 12:25:06
● 2026-05-08 13:38:04
●NSns-277.awsdns-34.com2026-05-05 → 2026-05-08 · 3 obs
● 2026-05-05 12:25:06
● 2026-05-08 13:38:04
●NSns-990.awsdns-59.net2026-05-05 → 2026-05-08 · 3 obs
● 2026-05-05 12:25:06
● 2026-05-08 13:38:04
○NSns1.savvis.net2015-07-06 → 2017-06-04 · 4 obs
● 2017-06-04 15:34:14
○ 2026-05-05 12:25:06
○ 2026-05-08 13:38:04
○NSns2.savvis.net2015-07-06 → 2017-06-04 · 4 obs
● 2017-06-04 15:34:14
○ 2026-05-05 12:25:06
○ 2026-05-08 13:38:04
○NSns3.savvis.net2015-07-06 → 2017-06-04 · 4 obs
● 2017-06-04 15:34:14
○ 2026-05-05 12:25:06
○ 2026-05-08 13:38:04
○NSns4.savvis.net2015-07-06 → 2017-06-04 · 4 obs
● 2017-06-04 15:34:14
○ 2026-05-05 12:25:06
○ 2026-05-08 13:38:04
○NSns5.savvis.net2015-07-06 → 2017-06-04 · 4 obs
● 2017-06-04 15:34:14
○ 2026-05-05 12:25:06
○ 2026-05-08 13:38:04
●A3.138.52.2492026-05-05 → 2026-05-08 · 2 obs
● 2026-05-08 13:38:04
●A3.21.30.2362026-05-08 → 2026-05-08 · 3 obs
● 2026-05-08 07:40:10
● 2026-05-08 13:38:04
○A3.23.162.842026-05-05 → 2026-05-05 · 3 obs
○ 2026-05-08 07:40:10
○ 2026-05-08 13:38:04
🔍 DNS Trace
📋 Delegation Chain
| Zone | Nameservers | Glue |
|---|---|---|
| com | a.gtld-servers.net, b.gtld-servers.net, c.gtld-servers.net, d.gtld-servers.net... | - |
| 21thcentury.com | ns-277.awsdns-34.com, ns-990.awsdns-59.net, ns-1260.awsdns-29.org, ns-1942.awsdns-50.co.uk | 2 records |
✅ Authoritative Response
Server:205.251.195.222
NS records: ns-277.awsdns-34.com, ns-990.awsdns-59.net, ns-1260.awsdns-29.org, ns-1942.awsdns-50.co.uk
🔒 DNSSEC Status
⚠️ Insecure (no DNSSEC)
No DS record for 21thcentury.com (unsigned zone)
⏱️ Timing
Total: 414ms | Queries: -
📄 Records
| Type | Count | Sample Data |
|---|---|---|
| A | 2 | 3.21.30.236, 3.138.52.249 |
| NS | 4 | ns-1260.awsdns-29.org, ns-1942.awsdns-50.co.uk... |
| SOA | 1 | ns-1260.awsdns-29.org awsdns-hostmaster. |
📌 Glue Records Collected
Total: 2
Out-of-bailiwick: 2 (ns-277.awsdns-34.com, ns-277.awsdns-34.com)
Analysis
IP Addresses
21thcentury.com resolves to two IPs: 3.21.30.236 and 3.138.52.249.
other host names for instance 21scentury.com, century21id.com, century21doral.com, century21smortgages.com and c21online.com share IP numbers with 21thcentury.com.
Name Servers
21thcentury.com is delegated to four name servers: ns-277.awsdns-34.com, ns-990.awsdns-59.net, ns-1260.awsdns-29.org and ns-1942.awsdns-50.co.uk.
21thcentury.com at least partially shares name servers with other domains, for instance dialog.rikstv.no, rmpdashboard.com, qasiteprotect.com, dwv6yco9mjzmi.cloudfront.net and fsmiil.com.
These name servers are commonly used with ns-1246.awsdns-27.org, ns-673.awsdns-20.net, ns-1641.awsdns-13.co.uk, a.ns.neolane.net, b.ns.neolane.net, c.ns.neolane.net, d.ns.neolane.net and e.ns.neolane.net.
Host names with two IP numbers:
Host name ns-277.awsdns-34.com points to: 2600:9000:5301:1500::1 and 205.251.193.21.
Host name ns-990.awsdns-59.net points to: 2600:9000:5303:de00::1 and 205.251.195.222.
Host name ns-1260.awsdns-29.org points to: 2600:9000:5304:ec00::1 and 205.251.196.236.
Host name ns-1942.awsdns-50.co.uk points to: 2600:9000:5307:9600::1 and 205.251.199.150.