Sh4mefulIP Address: 216.71.143.91 ⚠ 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.hc5995-21.iphmx.com
Last updated: 2/5/2026
Analysis
This IP was first observed on March 13, 2024 and most recently on July 2, 2025. It has been associated with 26 failed authentication events affecting 45 messages, representing significant volume. 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.
Failures Detected from this IP
Showing 1-26 of 26 failures, affecting 45 messages| Date ▼ | Messages |
|---|---|
| 7/2/2025 | 1 |
| 6/27/2025 | 3 |
| 6/18/2025 | 1 |
| 6/6/2025 | 1 |
| 6/4/2025 | 4 |
| 5/2/2025 | 4 |
| 12/18/2024 | 2 |
| 12/11/2024 | 1 |
| 12/5/2024 | 1 |
| 12/4/2024 | 1 |
| 11/21/2024 | 1 |
| 11/20/2024 | 2 |
| 11/13/2024 | 1 |
| 11/12/2024 | 1 |
| 11/6/2024 | 1 |
| 10/23/2024 | 3 |
| 9/27/2024 | 3 |
| 9/20/2024 | 1 |
| 9/13/2024 | 3 |
| 9/6/2024 | 1 |
| 8/21/2024 | 1 |
| 8/7/2024 | 1 |
| 6/12/2024 | 2 |
| 5/31/2024 | 2 |
| 4/17/2024 | 2 |
| 3/13/2024 | 1 |
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:
216.71.143.137 (8 failures)