Tair (Redis® OSS-Compatible):Perform diagnostics on connections

Prerequisites

Before you begin, ensure that you have:

• Access to the Alibaba Cloud console

• The client IP address you want to diagnose

Run connection diagnostics

1. Log on to the console and go to the Instances page. In the top navigation bar, select the region where the instance is deployed. Find the instance and click its ID.

2. In the Connection Information section, click Connection Diagnostics.

3. In the Connection Diagnostics panel, set the client type and IP address based on your setup:

   Client type	Setup
   ECS instance in the same region as the Tair instance	Set Client Type to ECS Instance and select the ECS instance ID. The ID color indicates network reachability: green means the ECS instance is in the same virtual private cloud (VPC) as the Tair instance (connectable over VPC or Internet); red means different VPCs (Internet only). Then select the endpoint to use for the connection.
   On-premises device, or ECS instance in a different region	Set Client Type to IP address and enter the client IP address. These clients connect over the Internet only.

4. Click Start Diagnostics.

5. Review the result:

   • Check passed: The IP address is whitelisted. Proceed to connect to the instance.

   • Check failed: The IP address is not whitelisted. Click Add to add it to the default whitelist, then run diagnostics again.

   Note

   To add the IP address to a specific whitelist instead of the default one, click Whitelist Settings and add the IP address manually on the Whitelist Settings page.

If the connection still fails after the check passes

Connection Diagnostics only verifies IP whitelisting. If the IP passes the check but the client still cannot connect, work through these checks in order:

1. Test network reachability. Run the following command from the client:

   ping <instance-endpoint>

   If the network connection is abnormal, check the client network environment.

2. Check for a dynamic IP address. If the client uses a dynamic IP on the Internet, the IP whitelisted during diagnostics may differ from the active IP at connection time. To resolve this, configure a static IP address for the client, or add 0.0.0.0/0 to the whitelist to allow access from all IP addresses.

3. Verify the instance password. If network reachability is confirmed, the failure may be an authentication error. Check the password configured for your instance. For details, see Connect to an instance.

What's next

After the diagnostic check passes, connect to the instance from your client:

• Use a client to connect to an instance

• Use redis-cli to connect to an instance