This topic provides answers to some frequently asked questions about Virtual Private Cloud (VPC).

What are the differences between a VPC and a classic network?

Differences between a VPC and a classic network:
  • A classic network is built on the public infrastructure of Alibaba Cloud. Services that are deployed in a classic network are managed by Alibaba Cloud. A classic network is suitable for users that require simplified networking.
  • A VPC is an isolated virtual network built by users on Alibaba Cloud. VPCs are logically isolated from each other. You can customize the topology of a VPC and the IP addresses in a VPC. Compared with a classic network, a VPC is suitable for users who have high network management requirements and capabilities.

Can I attach multiple network interface controllers (NICs) to an Elastic Compute Service (ECS) instance?

Each ECS instance in a classic network supports two NICs: a public NIC and a private NIC. Each ECS instance in a VPC supports only one private NIC. You can attach multiple Elastic Network Interfaces (ENIs) to specific types of ECS instances. For more information, see Overview.

Can a VPC have multiple vRouters?

No, each VPC can have only one vRouter. However, each vRouter can be associated with multiple route tables.

How many custom routes can I create in a route table?

By default, you can create at most 200 custom routes in a route table.

You can go to the Quota Management page to request a quota increase. For more information, see Manage service quotas.

How many vSwitches can I create in a VPC?

By default, you can create at most 150 vSwitches in a VPC.

You can go to the Quota Management page to request a quota increase. For more information, see Manage service quotas.

How many private IP addresses can be used by cloud services in each VPC?

In each VPC, cloud services can use a maximum of 60,000 private IP addresses. You cannot increase the quota.

If an ECS instance is assigned only one private IP address, the ECS instance uses one IP address. If multiple NICs are attached to an ECS instance or an NIC that is assigned multiple IP addresses is attached to the ECS instance, the ECS instance can use multiple IP addresses. The number of IP addresses used by the ECS instance equals the sum of IP addresses that are assigned to the NICs.