Routing
The policies in this stage enforce routing of requests to target APIs based on the rules you can define to route the requests and manage their respective redirections according to the initial request path. The policies included in this stage are:

Content-based Routing

Conditional Routing

Dynamic Routing

Load Balancer Routing

Straight Through Routing

Custom HTTP Header

Outbound Auth - Transport

Outbound Auth - Message

JMS/AMQP Routing

JMS/AMQP Properties

Custom Extension
Custom Extension policies allow you to handle requirements that might not be provided by the out-of-the-box policies. You can add these custom extensions into
API Gateway policy stages. To learn more about Custom Extension, see
Custom Policy Extension.
In cases where the internal server is protected by a firewall, the endpoint in the routing policy that is applied should be configured as apigateway://registrationPort-aliasname/relative path of the API. Here the registration port alias name is the alias name configured for the external registration port to communicate with the internal port.