Control Routing Behavior

[abokov]

When you put a virtual machine on a virtual network, the VM can connect to any other VM on the same virtual network, even if the other VMs are on different subnets. This is possible because a collection of system routes enabled by default allows this type of communication. These default routes allow VMs on the same virtual network to initiate connections with each other, and with the internet (for outbound communications to the internet only).

Best Practices

• Tune the default routing table entries in your virtual network. Although the default system routes are useful for many deployment scenarios, there are times when you want to customize the routing configuration for your deployments. You can configure the next-hop address to reach specific destinations.
• Ensure that your services are not allowed to initiate a connection to devices on the Internet by enabling Forced tunneling, all connections to the internet are forced through your on-premises gateway. You can configure forced tunneling by taking advantage of UDRs (user defined routes).