This topic describes how to allow ECS instances in classic networks and instances of E-MapReduce (EMR) clusters in VPCs to access each other.

Alibaba Cloud provides two network types: classic network and VPC. EMR clusters run in VPCs, while business systems of many users still run in classic networks. To connect these two types of networks, Alibaba Cloud launched the ClassicLink solution. For more information, see ClassicLink overview.

The procedure to implement this solution is as follows:

  1. Create a VSwitch based on the CIDR blocks described in the "ClassicLink overview" topic.
  2. Use the VSwitch to deploy an EMR cluster.
  3. In the ECS console, connect the required instances of a classic network to the VPC.
  4. Set security group rules.