Website Availability in Vietnam
Submarine cables, ISP health and blocking risks that decide whether a website loads in Vietnam. Checked against live measurement data.
Wondering whether a website is down for everyone or just unreachable from Vietnam? The answer usually hides in the physical layer of the internet. Vietnam 🇻🇳 connects to the global network through 8 submarine cable systems that come ashore at 3 landing stations, and its national domain zone is .vn. Every request from a user in Vietnam to a foreign server, and every request from abroad to a site hosted in Vietnam, physically travels over these systems or their terrestrial backhaul.
This page summarizes what our measurement network knows about internet connectivity in Vietnam: which cables serve the country, how its leading internet providers are performing, and what can make a website appear offline for users there while it works everywhere else.
Current connectivity status in Vietnam
As of our latest hourly measurement cycle, the national internet signal of Vietnam is operating normally (BGP visibility and active probing dip: 0.1% against the 24-hour baseline). National-level signals catch large events; an individual website can still be unreachable for local reasons, which is what the availability checker above is for.
Connectivity for most users in Vietnam is provided by a small group of networks:
| Provider | ASN | Share of users | Status |
|---|---|---|---|
| VIETEL-AS-AP - Viettel Group | AS7552 | 41.4% | No recent anomaly |
| VNPT-AS-VN - VNPT Corp | AS45899 | 33.3% | No recent anomaly |
| FPT-VN - FPT Telecom Company | AS18403 | 19.9% | No recent anomaly |
| MOBIFONE-AS-VN - MOBIFONE Corporation | AS131429 | 4.7% | No recent anomaly |
| VIETTEL-AS-VN - Viettel Corporation | AS24086 | 1.9% | No recent anomaly |
If a website fails to load only for customers of one of these providers, the problem is almost always local: DNS resolution inside that network, ISP-level filtering, or a routing issue, rather than the website itself being down.
Submarine cables that connect Vietnam to the internet
The following systems land in Vietnam. Cable length is a rough proxy for how much of the world a system reaches: long trunks connect continents, short ones link neighbors. Our monitors registered 1 latency anomalies on cables serving Vietnam in the last 30 days.
| Cable system | Length | In service since |
|---|---|---|
| Asia Africa Europe-1 (AAE-1) | 25,000 km | 2017 |
| Asia-America Gateway (AAG) Cable System | 20,000 km | 2009 |
| Southeast Asia-Japan Cable 2 (SJC2) | 10,500 km | 2025 |
| Asia Pacific Gateway (APG) | 10,400 km | 2016 |
| Asia Direct Cable (ADC) | 9,988 km | 2024 |
| Asia Link Cable (ALC) | 7,200 km | 2027 |
| Tata TGN-Intra Asia (TGN-IA) | 6,700 km | 2009 |
| Vietnam-Singapore Cable System (VTS) | n/a | 2027 |
How resilient is Vietnam to cable failures?
With 8 cable systems across 3 landing stations, Vietnam has a moderately concentrated topology. A fault on one of the main systems can noticeably degrade international bandwidth until repairs finish. Repairs at sea typically take one to several weeks, because a specialized cable ship has to locate the fault, lift the cable and splice it on deck.
Why a website may not load in Vietnam
When a site works in other countries but fails in Vietnam, the usual suspects are, in order of likelihood: a DNS problem inside a local ISP, a content delivery network misrouting users in Vietnam to an unhealthy edge node, a routing or peering issue between local networks and the site's host, and finally a submarine cable incident affecting the whole region.
Our DNS measurements have not flagged systematic national filtering in Vietnam, although individual ISPs and corporate networks can still block specific resources.
Neighbors on the same cables
These countries share submarine cable systems with Vietnam, so a major cable incident can affect them together:
🇸🇬 Singapore (7 shared) · 🇹🇭 Thailand (6 shared) · 🇲🇾 Malaysia (5 shared) · 🇵🇭 Philippines (4 shared) · 🇯🇵 Japan (3 shared) · 🇰🇷 South Korea (2 shared)
See the full list on the website availability by country hub.
Frequently asked questions
How do I check if a website is down in Vietnam?
Enter the URL into the free Global Availability Checker on this site. It compares measurement data from 80+ countries, including probes relevant to Vietnam, and shows in seconds whether the site is down everywhere or only unreachable from specific regions.
How many submarine cables connect Vietnam?
Vietnam is served by 8 submarine cable systems landing at 3 coastal stations. The longest systems are Asia Africa Europe-1 (AAE-1), Asia-America Gateway (AAG) Cable System, Southeast Asia-Japan Cable 2 (SJC2).
Why does a website work in other countries but not in Vietnam?
The most common causes are DNS failures inside a local ISP, CDN edge problems, routing issues between Vietnam and the hosting network, national filtering, and submarine cable faults. Testing the URL from multiple countries immediately narrows down which one it is.
Who are the largest internet providers in Vietnam?
The leading networks by user share are VIETEL-AS-AP - Viettel Group, VNPT-AS-VN - VNPT Corp, FPT-VN - FPT Telecom Company. Together they carry the majority of consumer traffic, so a problem inside any of them affects a large share of users in Vietnam.
Can a single cable failure disconnect Vietnam?
A full disconnect is unlikely, but a fault on a major system can noticeably slow international traffic.
Does Vietnam block websites?
We have not detected systematic national filtering in Vietnam, but individual ISPs and corporate networks can still block specific sites.
Data: GeoCables submarine cable telemetry, RIPE Atlas measurements, IODA national signals, APNIC user estimates. Numbers refresh automatically; last update July 11, 2026.