Public network

A public network is an internet-facing network providing physical connectivity for all servers. On some TCP and UDP ports, network traffic between the private network and the internet is limited. Some BareMetal server configurations support reserving MC-LAG public network channels.

When working with a public network and internet access, make sure to comply with the terms of use.

Ephemeral public subnetEphemeral public subnet

An ephemeral public subnet is a public subnet of the /31 size that is randomly assigned to a BareMetal server from the range of public IPv4 addresses reserved for Yandex BareMetal.

Ephemeral public subnets are assigned to servers with Public address set to From ephemeral subnet in their network parameters.

When leasing a BareMetal server, you can enable the DHCP server in an ephemeral public subnet. To do this, enable Assign via DHCP. Otherwise, the DHCP server in this subnet will be disabled. You will not be able to change the DHCP server settings in such subnet later.

If DHCP is disabled in an ephemeral public subnet or on the server's network interface connected to such a subnet, and obtaining an address via DHCP is disabled, consider the following when configuring that interface:

• The subnet the server's public IP address is in has a subnet prefix length of 31 bits and consists of these two addresses: the default gateway IP address and the host IP address.
• The gateway IP address is specified under Default gateway in the Public network section on the server information page.
• The host IP address is greater than the gateway IP address by one.

Here is an example:

• Subnet CIDR: 198.51.100.110/31.
• Default gateway IP address: 198.51.100.110.
• Server public IP address: 198.51.100.111.

You can convert an ephemeral public subnet to a dedicated public subnet of size /31; this dedicated public subnet of size /31 will be resolving the default gateway's IP address and the server's public address in the same way as the ephemeral subnet.

The lifecycle of an ephemeral public subnet depends on the lifecycle of the server this subnet is assigned to. When a server lease is cancelled, the ephemeral public subnet assigned to it will be automatically deleted and the server’s public IPv4 address will be released back to the BareMetal address pool.

Dedicated public subnetDedicated public subnet

A dedicated public subnet is a public subnet made up of an IP address range that will be available to your servers in the selected pools. The IP address range is assigned to the dedicated public subnet automatically.

You can order a dedicated public subnet in the following sizes:

¹ You can order a public subnet of size /31 only by converting an ephemeral public subnet.
² To order public subnets with sizes /27, /26, /25, and /24, contact support.

When you cancel the lease of a server which has a dedicated public subnet assigned to it, its public IPv4 address is released back to the dedicated public subnet’s address pool so you can later use it for another server.

In Yandex BareMetal, dedicated public subnets are billable. The minimum lease period for a dedicated public subnet is one month, so you cannot delete such a subnet during the first month after the order date.

IP address distribution in public subnetsIP address distribution in public subnets

The dedicated public subnet does not have a DHCP server; therefore, on the network interface of the server connected to such subnet, you should manually configure a static IP address from the subnet’s range of available public IP addresses and specify the default gateway address.

The information about the range of IP addresses available in a public subnet and default gateway is provided in the Public network section on the server information page and on the public subnet information page.

Within a dedicated public subnet range, IP addresses are distributed as follows:

See alsoSee also

• Network
• Private network
• DHCP in a Yandex BareMetal network
• Reserving a BareMetal network connection using MC-LAG
• Ordering a dedicated public subnet