When an SAG-100WM device loses connectivity to Alibaba Cloud, the root cause is typically one of four things: a faulty connection between the on-premises terminal and the device, a faulty VPN tunnel, an ECS instance issue, or an ISP network outage. Work through the steps below in order to isolate the problem.
Symptoms
An on-premises terminal cannot reach Alibaba Cloud. Common signs include:
A terminal connected to a Cloud Enterprise Network (CEN) instance cannot
pingElastic Compute Service (ECS) instances also connected to that CEN instance.A terminal connected to a Cloud Connect Network (CCN) instance cannot
pingclients also connected to that CCN instance.
Causes
| # | Possible cause |
|---|---|
| 1 | The connection between the on-premises terminal and the SAG-100WM device is faulty. |
| 2 | The VPN tunnel between the SAG-100WM device and Alibaba Cloud is faulty. |
| 3 | The ECS instance is faulty. |
| 4 | The Internet service provider (ISP) network is faulty. |
Troubleshooting steps
Step 1 — Check the SAG instance status
Log on to the SAG console.
Click the SAG instance ID and check whether the status is Ready.
| Status | Next action |
|---|---|
| Disconnected | The device has lost its connection to Alibaba Cloud. See SAG device disconnections for further troubleshooting. |
| Connected | The connection is intact. Proceed to Step 2. |
Step 2 — Check the CLOUD indicator light
Look at the physical SAG-100WM device and check whether the CLOUD indicator light is on.
| CLOUD light | Meaning | Next action |
|---|---|---|
| On | The VPN tunnel is error-free. | Log on to the ECS console and verify that the security group rules of the ECS instance allow network traffic from the on-premises network. |
| Off | The VPN tunnel is faulty. | Proceed to Step 3. |
Step 3 — Bypass the intermediary device
An intermediate device such as a router may be interfering with the WAN connection. Configure PPPoE on the WAN port and connect the WAN port directly to the ISP network, bypassing any router.
| CLOUD light after bypassing | Next action |
|---|---|
| On | The issue is resolved. |
| Off | Proceed to Step 4. |
Step 4 — Check the SAG device software
Check whether the software on the SAG device has errors. If errors are present, restart the SAG device.