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Public Cloud Networks

All virtual machines can be connected to a private network and a public network (the internet). The internet connection can be configured via Edge routers or Direct Connected subnets.

Public network

You can connect virtual machines to the public network (the Internet) using one of the following schemes:

  • via a local Edge router (by default). Virtual machines in a virtual data center are connected via a private network that connects to an Edge router, and the Edge router connects to the internet. Firewall and NAT must be configured on the Edge router;
  • via a Direct Connected subnet, which connects virtual machines and connects them to a public network without using a router. You must configure a Firewall on each virtual machine.

Connection via Edge Router

An Edge Router is a software router used by virtual machines to access the public network. Virtual machines communicate with the Edge Router via a private network.

When creating a virtual data center, a Compact-sized Edge router is automatically created with a preconfigured default_net private network and basic Firewall and NAT rules; for more information, see the Edge Routers instructions.

You can create a new Edge router and add a private network to it. After that, you need to configure the Firewall and NAT rules for SSH/RDP access. Additionally, you can configure a VPN and load balancing.

Connection via Direct Connected subnet

A Direct Connected subnet is a public subnet created at the virtual data center level, to which virtual machines connect directly and receive IP addresses from this network without using an additional router (Edge router) and without the need to configure Firewall and NAT. If the VMware Tools utility (the open-vm-tools package) is installed inside the virtual machine and network interface, the IP address will be added automatically when building the virtual machine.

A Direct Connected subnet can contain from 5 to 253 IPv4 addresses. The limit on Direct Connected subnets is five per organization. To increase the limit, submit a ticket.

For more information on working with Direct Connected subnets, see the Manage Direct Connected subnets instructions.

Private network

A network can be available within a virtual data center or a group of them and can be one of the following types:

  • Routed is a private network connecting virtual machines in a virtual data center with an Edge router. It is accessible from the internet if NAT rules are configured. When creating a virtual data center, a preconfigured default_net network of the Routed type is created automatically;
  • Isolated is a private network connecting virtual machines that is accessible only within a virtual data center and is not accessible from the internet. You can share such a network between virtual data centers within an organization; for details, see the Create a shared network between virtual data centers instructions.

Preconfigured private network default_net

The preconfigured default_net private network is created automatically after a virtual data center and a default (Compact size) Edge Router are created. You can use it to connect a virtual machine to the Internet.

default_net network specifications:

  • static address pool: 10.0.0.101 – 10.0.0.132;
  • DNS: Primary DNS 188.93.16.19 and Secondary DNS 188.93.17.19;
  • the network has Internet access: it is connected to an Edge Router with configured NAT and Firewall rules;
  • a DHCP server with an address pool of 10.0.0.2 – 10.0.0.100 is running on the network's Edge router.

Blocked ports

To protect the Selectel infrastructure from malicious network activity, we blocked certain ports, including 25 (mailings).

If a port is not covered by the listed restrictions, check its availability from the OS using the Nmap utility.