Connect subnet to routerΒΆ
For most situations, you would want to connect your subnet to your router so that you can for example reach the internet (or your other networks) through it.
This means giving your router an interface on the network on which the subnet is defined as well as an IP-address on the subnet, thereby enabling traffic to be routed to and from the subnet.
For instructions on how to connect a subnet to a router, a step-by-step guide is available based on your choice of management platform:
Tip
If the communication on the subnet is only local to the hosts that connect to it (and does not need to be routed, that is reach other networks), there is no need (and indeed its not advised) to connect the subnet to a router.
An example use-case where this might be true is a back-net on which for example database connections or backups run.
We generally recommend keeping it your setup clean and consistent and not use multi-homing, i.e connecting an instance to more than one subnet as troubleshooting your network will become much more pleasant.
The reason for multi-homing is historically related to either capacity (which is normally not an issue in a public cloud) or security (which might actually be worsened by badly maintained firewall rules).