The connection to a simple application server outside the Chinese mainland times out - Simple Application Server

SSH, Remote Desktop, and browser connections from the Chinese mainland to a simple application server in an overseas region can time out due to cross-border network latency and packet loss. This topic explains how to confirm the cause and resolve it.

Symptom

A connection to a simple application server deployed outside the Chinese mainland fails with a timeout error. Common error messages include:

SSH: ssh: connect to host <server-ip> port 22: Connection timed out
Remote Desktop: the connection attempt hangs and eventually times out
Browser: the page loads indefinitely or displays an ERR_CONNECTION_TIMED_OUT error

Cause

Cross-border network traffic between the Chinese mainland and overseas regions passes through international Internet service providers (ISPs). This routing introduces high latency and packet loss, which makes the server unreachable. The issue is in the international network path, not in Simple Application Server itself.

For available deployment regions, see Regions and network connectivity.

Diagnose the issue

Before applying a solution, confirm that cross-border latency is the root cause. If SSH is unavailable, use Remote Connection (Workbench) in the Simple Application Server console to access the server — Workbench connects through the Alibaba Cloud internal network and remains available even when the public network path is degraded.

Run the following commands from your local machine in the Chinese mainland.

Check latency and packet loss

ping <server-ip>

Round-trip times above 200 ms or repeated timeouts indicate cross-border network congestion. The following example shows a server experiencing severe packet loss:

PING 203.0.113.10 (203.0.113.10): 56 data bytes
Request timeout for icmp_seq 0
Request timeout for icmp_seq 1
64 bytes from 203.0.113.10: icmp_seq=2 ttl=44 time=387.201 ms

Trace the network path

For a more detailed view, use traceroute. It reports per-hop latency and helps pinpoint where the path fails.

traceroute <server-ip>

Look for timeouts (* * *) or high latency at international hops. Failures at hops outside the Chinese mainland confirm cross-border routing as the cause rather than a server-side problem.

Rule out firewall misconfiguration

Verify that the firewall rules on your simple application server allow inbound traffic on the required ports (for example, port 22 for SSH or port 3389 for RDP). In the Simple Application Server console, check the Firewall settings to confirm the relevant ports are open.

If the firewall rules are correct and traceroute shows failures only at international hops, cross-border network latency is the cause.

Solutions

Try the following solutions in order, from quickest to most involved.

Solution 1: Access the server through Remote Connection (Workbench)

For immediate access, use the browser-based remote console (Workbench) in the Simple Application Server console. Click Remote Connection on the server detail page, then select a connection method such as Connect with One-click on Workbench. This bypasses the public network and connects through the Alibaba Cloud internal network.

Solution 2: Retry from a different network

If the issue is intermittent, switch to a different local network — for example, switch from Wi-Fi to a mobile hotspot to rule out ISP-specific routing problems — or try again later. Cross-border network quality varies by time and ISP.

Solution 3: Migrate to a Chinese mainland region

If you consistently cannot reach the server and your users are primarily in the Chinese mainland, migrate your workload to a server in a Chinese mainland region. This eliminates the cross-border network path.

Two migration methods are available:

Method A: Direct data migration

Migrate the website data from the existing server to a new simple application server in a Chinese mainland region. For detailed steps, see Migrate data between simple application servers.

Method B: Custom image migration

Create a disk snapshot of the existing simple application server.
Create a custom image from the disk snapshot to preserve the full server configuration.
Use the custom image to create a new simple application server in a Chinese mainland region.

For details, see Overview of custom images and Use a custom image to create one or more simple application servers.

After you verify that the data migration is complete, submit a ticket to request a refund for the server deployed outside the Chinese mainland.

Simple Application Server:Connection timeout when accessing a simple application server outside the Chinese mainland