Sh4mefulIP Address: 216.71.143.137 ⚠ Network Confounder
Cloud Email Security sometimes breaks SPF and DKIM at the endpoint. Unclear if this is a configuration issue or byproduct the interception of email
This page shows DMARC authentication failure data for this IP address. Learn more about this data.
Geolocation Information
- Country:
- US United States
- Coordinates:
- 37.751, -97.822
WHOIS Information
- Network Name:
- CISL-7
- CIDR:
216.71.128.0/19- Owner:
- Cisco Systems Ironport Division
- Org ID:
CISL-7- Address:
- 170 West Tasman Drive, San Jose, CA 95134
- Reverse DNS:
-
esa.hc5997-4.iphmx.com
Last updated: 2/5/2026
Analysis
This IP was first observed on August 6, 2025 and most recently on December 19, 2025. It has been associated with 8 failed authentication events affecting 8 messages, representing moderate activity. The IP belongs to CISL-7 (Cisco Systems Ironport Division), a network with activity associated with United States. One other IP in the same /24 subnet (216.71.143.*) also appears in this dataset.
External Reputation Lookups
Look up this IP in external threat intelligence and reputation databases (opens in new tab):
Nearby IPs
Other IPs in the 216.71.143.0/24 range observed failing DMARC:
216.71.143.91 (26 failures)