Introduction to the Cisco CSR 1000v Route Tables
This section provides guidelines which will help you to decide user-defined routes to add to the route tables. When a Cisco CSR 1000v is deployed in a Virtual Network using the Microsoft Azure Marketplace template, a route table is created for each subnet to which the Cisco CSR 1000v has a network connection. For example, if you deploy a 4-NIC version of the Cisco CSR 1000v from the Microsoft Azure Marketplace, 4 subnets are created. Each subnet has an associated route table. No routes are automatically installed in the route table.
For further information on defining user-defined routes, also see the Microsoft Azure documentation: https://docs.microsoft.com/en-us/azure/, and search for "user defined routes".