:Solucionar falhas de conexão com uma instância Linux

Click Diagnostics to open the self-service troubleshooting page and select the target region.

Step 1: Test remote connection with Workbench

Use Workbench to make a remote connection. Workbench returns specific error messages and solutions if the connection fails. Follow these steps:

1. Go to ECS console - Instances.

2. In the upper-left corner of the page, select a region and resource group.

3. Click the ID of the target instance to go to the instance details page, and then click Remote connection.

4. In the Remote connection dialog box, find Workbench and click Sign in now.

5. Test whether you can remotely log on to the instance.

   Workbench automatically populates the basic information required to log on to the target instance. Confirm that the information is correct and enter your username and authentication credentials. For detailed steps on how to remotely log on to a Linux instance by using Workbench, see Connect to a Linux instance by using Workbench.

   • If you still cannot log on, Workbench returns an error message and a solution. Follow the instructions to resolve the issue. Then, test the remote connection again using Workbench. For information about common Workbench issues, see Troubleshoot VNC connection issues.

   • If you can log on using Workbench, the SSH service on the target instance is running correctly. This rules out SSH server-side issues. Proceed to Step 2: Check the network.

Step 2: Check the network

If you cannot remotely connect to a Linux instance, first, verify network connectivity.

1. Test the connection from a computer in a different network environment, such as on a different subnet or from a different ISP, to isolate the issue to either your local network or the instance.

   • If the issue is with your local network or ISP, contact your local IT staff or ISP for assistance.

   • If the network interface card driver is not working correctly, reinstall it.

2. On your local client, ping the instance to test network connectivity.

   • If you observe network anomalies, capture packets for analysis. For more information, see Use a packet capture tool to capture network packets.

   • If you experience packet loss or cannot ping the instance, use a tool like tracert or mtr to run a link test and identify the source of the problem. For more information, see Use MTR for network link analysis.

   • If ping is not disabled in the system kernel but you cannot ping the ECS instance, the instance's internal firewall may be dropping packets from your client.

     For more information, see Troubleshoot a failure to ping the public IP address of an ECS instance.

Step 3: Check the port and security group

Verify that the security group allows connections on the required remote port.

1. Go to ECS console - Instances.

2. In the upper-left corner of the page, select a region and resource group.

3. On the Instances page, click the ID of the corresponding instance.

4. On the Security Groups tab, find the security group and click Manage Rules in the Actions column.

5. On the Security Group Details page, in the Access Rules section, on the Inbound tab, click Add Rule and add a rule with the following parameters.

   • Policy: Allow

   • Priority: 1 (A lower value indicates a higher priority; 1 is the highest.)

   • Protocol: Custom TCP

   • Source: Set to your local IP address. You can find your IP address at https://cip.cc/.

   • Destination (This Instance): Select SSH (22).

6. Run the following command to test whether the port is open.

   telnet [IP] [Port]

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   • [IP] is the public IP address of the Linux instance.

   • [Port] is the SSH port number of the Linux instance.

   A successful response is similar to the following example from the telnet 192.168.0.1 22 command:

   Trying 192.168.0.1 ...
   Connected to 192.168.0.1.
   Escape character is '^]'

   If the port test fails, see Troubleshoot port connectivity issues on an ECS instance that can be pinged.

Step 4: Check CPU, bandwidth, and memory

High CPU load, insufficient public bandwidth, or insufficient memory can cause remote connection failures.

1. Check if the CPU load is high and take the appropriate action.

   • If the CPU load is high:

     If your application has heavy disk access, network access, or high computing demands, high CPU load is expected. To resolve this resource bottleneck, upgrade your instance type. For more information, see Overview of instance type upgrades and downgrades.

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     For solutions to high CPU load, see Query and analyze CPU load on Linux systems.

   • If the CPU load is not high, proceed to the next step.

2. Check whether the public bandwidth is insufficient.

   Insufficient public bandwidth can cause remote connection failures. Follow these steps to investigate:

   1. Go to ECS console - Instances.

   2. In the upper-left corner of the page, select a region and resource group.

   3. In the instance list, click the ID of the target instance. In the Configuration Information section, check the Public Bandwidth.

      If the instance bandwidth is 0 Mbit/s, the instance has no public bandwidth. To resolve this, upgrade the bandwidth. For more information, see Modify the bandwidth of a pay-as-you-go instance.

3. Check if there is insufficient memory.

   If you can connect to a Linux instance but the desktop does not display and the connection immediately closes without an error message, the issue may be insufficient instance memory. Check the instance's memory usage as follows:

   1. Log on to the Linux instance by using VNC.

      For more information, see Connect to a Linux instance by using a password.

   2. Check memory usage. If memory is insufficient, upgrade the instance type to resolve the resource bottleneck. For more information, see Overview of instance type upgrades and downgrades.