Subnets section

Each instance must have at least one connection type. CROC Cloud supports creating instances attached to a subnet and/or to a virtual switch, which is located in one Availability Zone. The features of these connection types are listed below.


  • provides L2 + L3 connectivity between instances;
  • connects to the Internet via the NAT gateway (this cannot be disabled at the moment);
  • IP addresses are automatically associated with instances according to the selected address block via DHCP protocol;
  • configuring security groups on network interfaces of instances in VPC;
  • configuring network ACLs on cross-subnets level;
  • has the IP-connectivity with other VPC subnets;
  • you can attach only one subnet to an instance;
  • you can attach a subnet to an instance only when creating an instance;
  • you can’t detach a subnet from an instance;
  • you can attach external networks to a subnet;
  • you can create a network interface in the subnet with Private IP Address of the subnet’s CIDR block and associate it with a public Elastic IP Address.

Creating subnets

Click некартинка_5 to create a subnet.

In the dialog window enter subnet’s IP-address. Optionally, you can supply AZ, in which you want to create a Subnet. In case you don’t supply AZ, the Cloud will choose one automatically. It is impossible to predict an AZ, which will be elected by the Cloud – consistency of choice is not guaranteed. Confirm the action to proceed.


You must specify an IP-address for a new subnet from the CIDR block range of your VPC. Subnet IP-address must be specified in CIDR notation (<subnet address>/<subnet prefix>). Subnet prefix can take values of the same range as VPC CIDR block prefix (from 16 to 28).

In the Subnets section you can see the list of instances attached to the subnet and the network ACL associated with this subnet.


Operations with network interfaces

The “Network interfaces” tab contains the list of network interfaces, created in this subnet.

More information about operation with network interfaces can be found in the “Network interfaces” section.

Associating with a network ACL

Click button_1 to associate a subnet with a network ACL. In the dialog window select a network ACL with which you want to associate the subnet and confirm the action.


You can associate with network ACL no more than 200 subnets of each VPC.

Deleting a subnet

Click некартинка_11 to delete a subnet. The subnet will be deleted after your confirmation.


Before deleting the subnet please make sure that it contains no instances, network interfaces or external networks. Otherwise an error message will be displayed saying the subnet is not empty.