# 171.251.234.21 — IP Intelligence Summary

171.251.234.21 is an IPv4 address operated by IRT-VNNIC-AP (AS7552), geolocated to Ho Chi Minh City, Vietnam. Its reverse DNS name is dynamic-adsl.viettel.vn. As of October 6, 2026, IPDebrief rates it Low Risk (0/100); no anonymizing service was detected.

- Canonical page: https://ipdebrief.com/171.251.234.21
- Last updated: 2026-10-06

## 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: Ho Chi Minh City
- Region: Ho Chi Minh
- 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: Low Risk (0/100)
- Blocklist listings: 0
- Suspicious activity indicators: no
- Spam source: no

## Reverse DNS

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

## Analyst narrative

\## IP Intelligence Briefing: 171.251.234.21/32

**Classification:** Low Risk (Risk Score: 25)

**Status:** Active Defensive Assessment Complete

**Network Identity:**

IP 171.251.234.21 is registered to Vietnam (VN), Ho Chi Minh City, under ASN 7552 (IRT-VNNIC-AP), organizational block VIETTEL-VN. The address belongs to CIDR block 171.224.0.0/11, classified as a provider infrastructure. DNS resolution maps to dynamic-adsl.viettel.vn with forward resolution confirmed.

**Threat Assessment:**

The IP maintains a low-risk posture with a risk score of 25. No threat indicators were observed during profiling. The address is not identified as a Tor exit node, known attacker, spam source, or proxy. Blacklist enumeration returned zero hits across major feeds. Control plane analysis identified one DNSBL listing among eight total lists checked, indicating minimal operator-level risk.

**Network Behavior:**

Services enumeration revealed no open ports and no active services. The network role is classified as provider-type infrastructure with firewalling enabled. Historical signal observations (16 total) indicate clean classification across recent assessments. No persistent malicious behavior was detected, with zero threat observation count and zero threat persistence days recorded.

**Geolocation Confidence:**

Geolocation data shows 52% confidence placing the address in Vietnam at coordinates (14.06, 108.28), with 600km accuracy radius. Multiple signal sources corroborated the country-level assessment.

**Subnet Analysis:**

The /24 neighborhood (171.251.234.21/24) exhibits zero abuse density with clean classification. No sibling IPs within the subnet showed elevated threat characteristics. Zero high-risk and zero medium-risk neighbors detected among the 254 available addresses.

**Associated Entities:**

Nine relationships were identified, including four same-network associations with VIETTEL-VN and five DNS associations mapping to dynamic-adsl.viettel.vn. No certificate correlations or known campaign affiliations were discovered.

**Recommended Actions:**

No immediate blocking or filtering actions required. The IP presents as legitimate provider infrastructure with low-risk characteristics. Standard monitoring practices apply.

## Nearby addresses

- 171.251.234.11 (https://ipdebrief.com/171.251.234.11)
- 171.251.234.56 (https://ipdebrief.com/171.251.234.56)
- 171.251.234.164 (https://ipdebrief.com/171.251.234.164)
- 171.251.234.205 (https://ipdebrief.com/171.251.234.205)

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Source: IPDebrief, "171.251.234.21 IP intelligence", https://ipdebrief.com/171.251.234.21, updated 2026-10-06. Assessments are probabilistic.