> ## Documentation Index
> Fetch the complete documentation index at: https://docs.nebius.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Allocating custom private addresses to resources

By default, Nebius AI Cloud [networks](/vpc/overview#network) and [subnets](/vpc/overview#subnet) provide private IP addresses from specific [CIDR blocks](https://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing#CIDR_blocks). These blocks depend on the network's or subnet's region. If you need private addresses outside these blocks, add the required CIDR block to one of the network's [pools](/vpc/overview#pool), or create a new pool and add it to the network. A pool must belong to the network before its addresses can be used in that network's subnets. Next, create a subnet with that CIDR block in the network. As a result, you can allocate random or specific addresses from this block in the required network or subnet.

## Prerequisites

1. Make sure you are in a [group](/iam/authorization/groups/index) that has at least the `editor` role within your tenant or project; for example, the default `editors` group. You can check this in the [Administration → IAM](https://console.nebius.com/iam) section of the web console.
2. Install and initialize the [Nebius AI Cloud CLI](/cli/quickstart).
3. Install [jq](https://jqlang.github.io/jq/) to extract IDs and tokens from the JSON data returned by the Nebius AI Cloud CLI:

   <CodeGroup>
     ```bash Ubuntu theme={null}
     sudo apt-get install jq
     ```

     ```bash macOS theme={null}
     brew install jq
     ```
   </CodeGroup>

## How to allocate addresses

1. Determine what CIDR block you need and save it to an environment variable. The block must fall within the [RFC 1918](https://datatracker.ietf.org/doc/html/rfc1918#section-3) private address ranges: `10.0.0.0/8`, `172.16.0.0/12` or `192.168.0.0/16`, and must not overlap with CIDR blocks already used by other pools or subnets in the network, or with external networks the VM reaches over a [Nebius VPN Gateway](/vpc/nebius-vpn-gateway).

   ```bash theme={null}
   export CUSTOM_SUBNET_CIDR=<CIDR_block>
   ```

   <Note>
     When you choose a custom CIDR block, do not use `172.17.0.0/16`. It conflicts with the Docker default bridge network and can make virtual machines unreachable. For more information, see [Virtual machine is unreachable due to a Docker subnet conflict](/compute/virtual-machines/docker-subnet-conflict).
   </Note>

2. Get the ID of the required network and save it to an environment variable:

   ```bash theme={null}
   export NETWORK_ID=$(nebius vpc network get-by-name \
     --name <network_name> \
     --format json | jq -r ".metadata.id")
   ```

3. Get the ID of this network's private pool and save it to an environment variable:

   ```bash theme={null}
   export PRIVATE_POOL_ID=$(nebius vpc network get \
     --id $NETWORK_ID \
     --format json | jq -r ".spec.ipv4_private_pools.pools[0].id")
   ```

   As this command contains `pools[0]`, it saves the ID of the private pool that goes first in the network specification. If you need a different pool, specify its index in `pools[<index>]`. To check the order of pools, run <code>nebius vpc network list</code>.

4. Add the `CUSTOM_SUBNET_CIDR` block to the private pool with `PRIVATE_POOL_ID`:

   ```bash theme={null}
   echo $(nebius vpc pool get --id $PRIVATE_POOL_ID --format json | \
     jq '.spec.cidrs += [{"cidr":$ENV.CUSTOM_SUBNET_CIDR}] |
     {metadata: .metadata, spec: .spec}') | \
     nebius vpc pool update -
   ```

5. Create a new subnet with this private pool and save the subnet ID to an environment variable:

   ```bash theme={null}
   export SUBNET_ID=$(nebius vpc subnet create \
     --name private_subnet \
     --network-id $NETWORK_ID \
     --ipv4-private-pools-pools "[{\"cidrs\":[{\"cidr\":\"$CUSTOM_SUBNET_CIDR\"}]}]" \
     --format json | jq -r ".metadata.id")
   ```

6. (Optional) To assign the VM a specific IP address, create an [allocation](/vpc/overview#allocation) within this subnet and save its ID to an environment variable:

   ```bash theme={null}
   export ALLOCATION_ID=$(nebius vpc allocation create \
     --name private_allocation \
     --ipv4-private-subnet-id $SUBNET_ID \
     --ipv4-private-cidr <IP_address> \
     --format json | jq -r ".metadata.id")
   ```

   The `--ipv4-private-cidr` parameter sets the IP address for the allocation. Make sure that this address is within the subnet's CIDR block. Without this parameter, the command creates an allocation with a random IP address from the subnet.

7. [Create a VM](/compute/virtual-machines/manage#create-a-vm) in the new subnet:

   ```bash theme={null}
   nebius compute instance create \
     --name <VM_name> \
     --stopped <true|false> \
     --resources-platform <platform> \
     --resources-preset <preset> \
     --boot-disk-existing-disk-id <boot_disk_ID> \
     --boot-disk-attach-mode READ_WRITE \
     --network-interfaces '[{"name": "<network_interface_name>", "subnet_id": "<subnet_ID>", "ip_address": {}, "public_ip_address": {}}]'
   ```

   The VM is assigned a private IP address from the subnet's pool. To assign the specific address from the allocation instead, set `ip_address` to `{"allocation_id": "$ALLOCATION_ID"}` inside the `--network-interfaces` parameter. If you later delete the VM, you can reuse the allocation for another VM.