User-defined routes
When you create subnets, Azure creates system routes that enable all the resources in a subnet so that they can communicate with each other. Every subnet has a default system route table, which contains the following minimum routes:
- Local VNet: This is a route for resources that reside in the VNet. For these routes, there is no next hop address. If the destination IP address contains the local VNet prefix, traffic is routed there.
- On-premises: This is a route for defined on-premises address spaces. For this route, the next hop address will be the VNet gateway. If the destination IP address contains the on-premises address prefix, traffic is routed there.
- Internet: This route is for all the traffic that goes over the public internet, and the internet gateway is always the next hop address. If the destination IP address doesn't contain the VNet or on-premises prefixes, traffic is routed to the internet using Network Address Translation (NAT). ...