Route Table Overview

Route tables are used by enterprise routers to forward packets. Each route table contains associations, propagations, and routes. Route tables are classified into custom route tables and default route tables.

**Table 1** Route tables
Route Table	Description
Custom route table	A custom route table is an additional route table you optionally create for an enterprise router. An enterprise router can have multiple custom route tables. You can associate attachments with different route tables to enable communication or isolation between network instances.
Default route table	A default route table is automatically created when an enterprise router is created. There are two types of default route tables: default association route table and default propagation route table. You can specify a route table both as the default association route table and the default propagation route table. You can also specify one route table as the default association route and another route table as the default propagation route table. If Default Route Table Association is enabled and the default association route table is specified, attachments will be associated with the default association route table. If no default association route table is specified, a route table named defaultRouteTable will be created and used as the default association route table. If Default Route Table Propagation is enabled and the default propagation route table is specified, attachments will be propagated to the default propagation route table. If no default propagation route table is specified, a route table named defaultRouteTable will be created and used as the default propagation route table. If both Default Route Table Association and Default Route Table Propagation are enabled but the default association route table and the default propagation route table are not specified, the route table named defaultRouteTable will be used as both the default association route table and the default propagation route table. If there is already a route table named defaultRouteTable, no additional defaultRouteTable will be created. You can replace the default route table with a custom route table if needed.