Help Center/ Virtual Private Cloud/ Drawer/ Creating a VPC with a Default Subnet/ Associated Route Table
Updated on 2025-07-11 GMT+08:00
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Associated Route Table

Description

A route table contains a set of routes that are used to determine where network traffic is directed. Each VPC comes with a default route table. Subnets in the VPC are then automatically associated with the default route table. The default route table ensures that subnets in a VPC can communicate with each other.

If the default route table cannot meet your requirements, you can create a custom route table after creating a VPC and associate subnets in the VPC with the custom route table. Then, the default route table controls inbound traffic of the subnets, and the custom route table controls outbound traffic of the subnets. Creating a Custom Route Table

FAQ

Can a Route Table Span Multiple VPCs?

No, a route table cannot span multiple VPCs.

A route table contains a set of routes that are used to determine where network traffic from your subnets within a given VPC is directed.

How Do I Add, Modify, and Delete Routes in a Route Table?

System routes in the VPC route table are automatically added by the system and cannot be modified or deleted.

You can add, modify, and delete custom routes in both default and custom route tables. The next hop type of a custom route can be an ECS, an extension NIC, a NAT gateway, a VPC peering connection, or a virtual IP address.

What Do I Need to Note When Adding a VPC Route?

  • Routes in a VPC route table are matched based on the longest prefix match rule.

    For example, suppose a system receives traffic destined for 10.0.0.2 and there are two routes in the route table, A and B. The destination for A is 10.0.0.0/16, and the destination for B is 10.0.0.0/30. In this example, route B is the best match, and traffic will be forwarded based on route B.

  • Routes with the same destination cannot exist in the same route table, regardless of whether the next hop types of the routes are the same.

    For example, route A in a route table has 10.0.0.0/16 as the destination and ECS as the next hop type. If you want to add route B with 10.0.0.0/16 as the destination and NAT gateway as the next hop type, route B will fail to be added due to destination conflict.

Parent Topic: Creating a VPC with a Default Subnet