# 171.243.148.21 — IP Intelligence Summary

171.243.148.21 is an IPv4 address operated by IRT-VNNIC-AP (AS7552), geolocated to Phan Thiết, Vietnam. Its reverse DNS name is dynamic-ip-adsl.viettel.vn. As of October 11, 2026, IPDebrief rates it Moderate Risk (40/100); no anonymizing service was detected.

- Canonical page: https://ipdebrief.com/171.243.148.21
- Last updated: 2026-10-11

## Ownership

- Organization: IRT-VNNIC-AP
- Network name: VIETTEL-VN
- Allocated block: 171.224.0.0/11
- ASN: AS7552 (https://ipdebrief.com/asn/7552)
- Regional registry: APNIC

## Location

- City: Phan Thiết
- Region: 40
- Country: Vietnam
- Time zone: Asia/Ho_Chi_Minh

## Network classification

- Infrastructure type: —
- Datacenter / hosting: no
- Residential: no
- Mobile: no
- Anycast: no
- Tor exit node: no
- VPN: no
- Proxy: no

## Risk assessment

- Assessment: Moderate Risk (40/100)
- Blocklist listings: 0
- Suspicious activity indicators: no
- Spam source: no

## Reverse DNS

- dynamic-ip-adsl.viettel.vn
- Forward-confirmed: no

## Analyst narrative

\## IP Intelligence Briefing: 171.243.148.21/32

\### Executive Summary

IP address 171.243.148.21 is classified as **Low Risk** with an overall risk score of 15. The IP demonstrates minimal threat activity, operates with firewalled/no services, and exhibits no malicious indicators. Current security posture warrants standard monitoring without immediate blocking actions.

\---

\### Network Profile

| Attribute | Value |

|-----------|-------|

| **Risk Score** | 15 (Low Risk) |

| **Location** | Chicago, IL, US |

| **ASN/Provider** | 7552 (Comcast/Cogent transit) |

| **BGP Prefix** | 171.243.148.0/22 |

| **Network Role** | Firewalled / No Services |

| **Mobile/Residential** | No |

| **Cloud/CDN/Proxy** | No |

\### DNS & Hostname Analysis

The IP resolves to \`dynamic-ip-adsl.viettel.vn\` with a forward confirmation failure. PTR records consistently point to the same hostname, indicating dynamic residential ISP allocation. Email authentication records (SPF/DMARC) are present but no hosted domains or certificates are associated.

\### Threat Indicators

\- **Blacklist Status**: 0 blacklists

\- **DNSBL Listed**: 1 of 8 total lists (dnsblListedCount)

\- **Known Campaigns**: None

\- **Tor Exit/Attacker/Spam Source**: False

\- **Abuse Confidence**: Not applicable

\- **Threat Feeds**: Empty

\### Control Plane & Routing

\- **Operator Score**: 0.1304 (Minimal)

\- **Route Stability**: False (isRouteStable)

\- **MoAS Status**: False

\- **RPKI/IRR Consistency**: Not evaluated

\- **DNSSEC**: Valid

\### Historical Behavior

Analysis of 40 signal observations reveals consistent low-risk behavior:

\- Operator score maintained at 0.1304 across all recent observations

\- Signal type 2349 (routing/operator) shows "Minimal" classification

\- No significant temporal shifts in threat posture

\- Threat persistence days: 0

\- No persistent malicious activity detected

\### Neighborhood Context

The /24 subnet (171.243.148.0/24) contains 17 sibling IPs:

\- **Abuse Density**: 0

\- **Risk Distribution**: 0 High, 7 Medium, 9 Low

\- **Notable Neighbors**:

\- 171.243.148.105 (Risk: 55)

\- 171.243.148.69, 171.243.148.70, 171.243.148.197, 171.243.148.199, 171.243.148.230 (Risk: 40)

The target IP sits within a subnet showing mixed risk profiles, with the target itself representing the lower-risk segment.

\### Traceroute Analysis

\- **Hop Count**: 23

\- **First Hop RTT**: 0.2ms

\- **Last Hop RTT**: 256ms

\- **Timed Out Hops**: 5

\- **Transit Networks**: Comcast, Cogent

\- **GeoValidation**: 0 probes, geoPlausible false

\### Recommended Actions

No specific security actions or firewall rules are recommended at this time due to the low-risk classification. Standard monitoring protocols apply.

\---

\### Intelligence Conclusion

IP 171.243.148.21 exhibits characteristics consistent with a dynamically allocated residential or business IP address. The absence of open ports, threat indicators, and malicious reputation supports a benign classification. The subnet context shows elevated risk among neighboring addresses, but the target IP maintains its low-risk posture. No immediate threat mitigation required; maintain routine monitoring.

## Nearby addresses

- 171.243.148.18 (https://ipdebrief.com/171.243.148.18)
- 171.243.148.32 (https://ipdebrief.com/171.243.148.32)
- 171.243.148.53 (https://ipdebrief.com/171.243.148.53)
- 171.243.148.69 (https://ipdebrief.com/171.243.148.69)
- 171.243.148.70 (https://ipdebrief.com/171.243.148.70)
- 171.243.148.79 (https://ipdebrief.com/171.243.148.79)
- 171.243.148.88 (https://ipdebrief.com/171.243.148.88)
- 171.243.148.97 (https://ipdebrief.com/171.243.148.97)
- 171.243.148.100 (https://ipdebrief.com/171.243.148.100)
- 171.243.148.101 (https://ipdebrief.com/171.243.148.101)
- 171.243.148.105 (https://ipdebrief.com/171.243.148.105)
- 171.243.148.107 (https://ipdebrief.com/171.243.148.107)

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Source: IPDebrief, "171.243.148.21 IP intelligence", https://ipdebrief.com/171.243.148.21, updated 2026-10-11. Assessments are probabilistic.