tencent cloud

Overview

CCN can interconnect a VPC with another VPC or a local IDC. To use CCN access, you must establish cross-VPC and VPC-IDC interconnections through CCN in advance.

In this scenario, you have used CCN to interconnect the following three networks: vpc-Guangzhou, vpc-Nanjing, and vpc-Shanghai, and plan to migrate a database in the Guangzhou region to the target database. vpc-Nanjing or vpc-Shanghai is selected as the VPC associated with CCN.

Directions

Establish interconnections as instructed in Network Instance Interconnection in One Account.

Note：

CCN only provides bandwidth below 10 Kbps between all regions free of charge. However, DTS requires a higher bandwidth. Therefore, bandwidth configuration in the link is required.

Subsequent Steps

1. On the DTS task page, select CCN.

   Parameter	Description	Sample Value
   VPC-Based CCN Instance	CCN instance name.	ccn6-xxxx7d
   CCN-Associated VPC	Select a VPC whose name and region are different from those of the VPC of the source database. For example, if you use a database in the Guangzhou region as the source database, you should select **vpc-Nanjing** or **vpc-Shanghai** as the **CCN-associated VPC**. Here, **vpc-Nanjing** is selected.	vpc-Nanjing
   Subnet	Name of the subnet of the selected VPC. If you cannot pull the subnet, there may be a problem with your account. The account of the CCN-associated VPC must be the same as the migration account. For example, to migrate a database under account A to account B, you should use account B to create a task. Therefore, the CCN-associated VPC must be under account B.	vpc-Nanjing-subnet
   Host Address	IP address of the source database server.	172.16.0.0
   Port	Port used by the source database. Below are the default ports for common databases (if they are modified, enter the actual ports): MySQL: 3306 SQL Server: 1433 PostgreSQL: 5432 MongoDB: 27017 Redis: 6379	3306

2. Click Test Connectivity. If the test fails, troubleshoot as follows:

   • The Telnet test fails.
     In the CCN-associated VPC (vpc-Nanjing in this example), purchase a CVM instance and ping the source database server address from it:
     • If the address is unpingable:
       • The server where the source database resides has a security group or firewall configured.
       • The SNAT IP address is blocked in the source database.
       • The port settings of the source database are incorrect.
       • Some route tables in the CCN instance are not enabled due to IP range conflicts.
     • If the address is pingable, the routing between the source database and CCN is normal.
       • The selected CCN-associated VPC is incorrect.
         The CCN-associated VPC and host address cannot be in the same region (if the network environment of the source database is a VPC in Guangzhou, you cannot select another VPC in Guangzhou as the CCN-associated VPC). The CCN-associated VPC and host address cannot be in the same VPC (if the network environment of the source database is VPC-A, you cannot select VPC-A as the CCN-associated VPC).
       • Submit a ticket for assistance.
   • The Telnet test is passed, but the database connection fails.
     • The migration account is not properly authorized. Authorize it again as instructed in the corresponding scenario in data migration and data sync.
     • The account or password is incorrect.