Hostname
c21.com
Last fetched
c21.com resolves to 9 IPv4 addresses operated by AMAZON-02 - Amazon.com, Inc. in US. WHOIS lists iana:299 as the registrar.
Nutrition Label
Resolution chain
c21.com resolves to 9 distinct IPv4 addresses via WhisperGraph DNS data. Each row links to the IP, prefix, and announcing ASN.
| IP | Prefix | ASN | Operator | Country |
|---|---|---|---|---|
| 18.223.218.162 | 18.220.0.0/14 | AS16509 | AMAZON-02 - Amazon.com, Inc. | US |
| 18.223.54.239 | 18.220.0.0/14 | AS16509 | AMAZON-02 - Amazon.com, Inc. | US |
| 18.225.134.189 | 18.224.0.0/14 | AS16509 | AMAZON-02 - Amazon.com, Inc. | US |
| 3.128.243.99 | 3.128.0.0/15 | AS16509 | AMAZON-02 - Amazon.com, Inc. | US |
| 3.134.9.3 | 3.132.0.0/14 | AS16509 | AMAZON-02 - Amazon.com, Inc. | US |
| 3.151.131.2 | 3.144.0.0/13 | AS16509 | AMAZON-02 - Amazon.com, Inc. | US |
| 3.151.3.154 | 3.144.0.0/13 | AS16509 | AMAZON-02 - Amazon.com, Inc. | US |
| 3.21.32.51 | 3.20.0.0/14 | AS16509 | AMAZON-02 - Amazon.com, Inc. | US |
| 18.225.65.154 | 18.224.0.0/14 | AS16509 | AMAZON-02 - Amazon.com, Inc. | US |
WHOIS identity
- Registrar
- iana:299
- Organization
- bryan engelhardt
- Contact emails
Subdomains
8,166 observed subdomains of c21.com.
Showing 25 of 8,166. View all subdomains →
Web-graph footprint
Distinct hostnames that link to or from c21.com in the public web crawl.
15 sites link to this hostname.
1 site linked to from this hostname.
Sample inbound links
Sample outbound links
Threat posture
History
Mail and authentication
MX records
SPF policy
11 SPF mechanisms authorising senders for c21.com.
| Mechanism | Target |
|---|---|
| SPF_A | svvssmtp.century21.com |
| SPF_INCLUDE | sendgrid.net |
| SPF_INCLUDE | spf.anywhere.re |
| SPF_INCLUDE | spf.protection.outlook.com |
| SPF_INCLUDE | spf.usa.net |
| SPF_IP | 216.136.162.64/26 |
| SPF_IP | 63.240.103.0/26 |
| SPF_IP | 64.37.197.198 |
| SPF_IP | 64.37.197.45 |
| SPF_IP | 64.37.197.6 |
| SPF_MX | c21.com |
Related pages
Pivot deeper into the graph from c21.com.
- IP · 18.223.218.162
- ASN · AS16509AMAZON-02 - Amazon.com, Inc.
- Registrar · iana:299
- Country · US
- Email · rfgdns@realogy.com
- TLD · .com
- Browse hostnames · c2…
- Glossary · What is a hostname?
- Whisper Internet Directory — home
- Live MOAS conflicts feed
- Threat feed · Spamhaus DROP
- United States internet infrastructure
Cypher and MCP
Reproduce the resolution chain directly against graph.whisper.security:
MATCH (h:HOSTNAME {name: "c21.com"})-[:RESOLVES_TO]->(ip:IPV4)
-[:ANNOUNCED_BY]->(ap:ANNOUNCED_PREFIX)
-[:ROUTES]->(asn:ASN)-[:HAS_NAME]->(n:ASN_NAME)
RETURN ip.name AS ip, ap.name AS prefix, asn.name AS asn, n.name AS operator
LIMIT 20Or query Whisper from your own LLM workflow via the Whisper MCP server.