---

Dear Valued Customers,

Thank you for trusting and using vHost’s services over the past time.

To better support our customers, vHost has planned a maintenance for the Cloud Server system at the Viettel Ho Chi Minh City Data Center. vHost would like to inform you of the details as follows:

Start time: From 17:00 on January 06, 2025 (GMT +7:00 – Vietnam Time).

End time: Until 20:00 on January 06, 2025 (GMT +7:00 – Vietnam Time).

Maintenance scope: Cloud Server system maintenance.

Impact: No impact.

Note: The above time is an estimated schedule, and the maintenance may be completed earlier than expected.
vHost will closely monitor the system throughout the maintenance period to support customers if necessary.

If you require further assistance, please contact vHost via the following channels:

Call Center: 1900 6806 – Press 2 (Technical Department)
Email: support@vhost.vn

Sincerely,

Service: Cloud Server, VPS

---

Dear Customers,

Thank you for trusting and using the services at vHost during the past time.

To ensure optimal system performance and enhance service quality, vHost will be conducting maintenance on the Email Gateway system. We would like to provide the specific details regarding this maintenance as follows:

Start time: From 23:00 on January 5, 2026 (GMT +7:00 Vietnam Time).

End time: To 02:00 on January 6, 2026 (GMT +7:00 Vietnam Time).

Maintenance scope: Maintenance, optimization, and upgrade of the Email Gateway system.

Impact: Services will be redirected to the backup Email Gateway; there will be no service interruption.

In case you need further support, please contact vHost through the following channels:

Call Center: 1900 6806 - press 2 (Technical Department)
Email: support@vhost.vn

Best Regards,

Service: Email, Email Relay

---

The system has recorded an incident affecting the service at Viettel Ho Chi Minh. Our technical team is currently investigating and resolving the issue.

Incident Update #1:

Based on our initial inspection, we have identified that the cause is related to a network issue, which has resulted in the current situation. We are actively working on resolving the problem.

Incident Update #2:

vHost has implemented a temporary fix, and the services at the Viettel Ho Chi Minh City Data Center are now accessible. Currently, vHost’s engineering team is urgently identifying the root cause and will resolve the issue thoroughly. We will update our valued customers with the latest information as soon as there are further developments.

Incident Update #3:

Incident Details
- Incident occurrence time: 08:59 on December 30, 2025 (GMT +7:00 Vietnam Time).
- Issue resolution completed at: 09:41 on December 30, 2025 (GMT +7:00 Vietnam Time).
- Impact level: Internet connectivity of services at Viettel Ho Chi Minh City Datacenter.
Incident Overview
- The network system experienced a complete loss of connectivity due to an incorrect firewall rule configuration change on the Core Router. The issue was resolved by rolling back to the previously stable configuration.
Root Cause:
-The issue was caused by an engineer mistakenly modifying a firewall rule on the router, resulting in all connections to the router’s Public and Management networks being blocked.
Temporary Mitigation Measures
- Redirected traffic to the backup device to restore connectivity.
- Removed the misconfigured firewall rule.
- Switched traffic back to the primary device after the issue on the primary device was resolved.
Preventive Measures
- Review and implement a direct console access system to routers to ensure immediate availability during incidents across all datacenters.

vHost would like to provide our valued customers with a detailed notification regarding the network incident mentioned above.
Thank you for your understanding regarding this incident.
Best regard.

Server, Email, VPS